Merge branch 'GP-2644_ghidra_LinkedFolders'

Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/DebuggerCoordinates.java

@@ -27,6 +27,7 @@ import ghidra.framework.data.ProjectFileManager;
 import ghidra.framework.model.*;
 import ghidra.framework.options.SaveState;
 import ghidra.framework.plugintool.PluginTool;
+import ghidra.framework.store.LockException;
 import ghidra.trace.database.DBTraceContentHandler;
 import ghidra.trace.model.Lifespan;
 import ghidra.trace.model.Trace;
@@ -643,6 +644,7 @@ public class DebuggerCoordinates {
 		ProjectData projData = tool.getProject().getProjectData(projLoc);
 		if (projData == null) {
 			try {
+				// FIXME! orphaned instance - transient in nature
 				projData = new ProjectFileManager(projLoc, false, false);
 			}
 			catch (NotOwnerException e) {
@@ -650,7 +652,7 @@ public class DebuggerCoordinates {
 					"Not project owner: " + projLoc + "(" + pathname + ")");
 				return null;
 			}
-			catch (IOException e) {
+			catch (IOException | LockException e) {
 				Msg.showError(DebuggerCoordinates.class, tool.getToolFrame(), "Trace Open Failed",
 					"Project error: " + e.getMessage());
 				return null;

Ghidra/Debug/Debugger/src/main/java/ghidra/app/plugin/core/debug/service/tracemgr/DebuggerTraceManagerServicePlugin.java

@@ -368,7 +368,18 @@ public class DebuggerTraceManagerServicePlugin extends Plugin
 		if (traceChooserDialog != null) {
 			return traceChooserDialog;
 		}
-		DomainFileFilter filter = df -> Trace.class.isAssignableFrom(df.getDomainObjectClass());
+		DomainFileFilter filter = new DomainFileFilter() {
+
+			@Override
+			public boolean accept(DomainFile df) {
+				return Trace.class.isAssignableFrom(df.getDomainObjectClass());
+			}
+
+			@Override
+			public boolean followLinkedFolders() {
+				return false;
+			}
+		};
 
 		// TODO regarding the hack note below, I believe this issue ahs been fixed, but not sure how to test
 		return traceChooserDialog =

Ghidra/Debug/Debugger/src/test/java/ghidra/app/plugin/core/debug/service/url/ProjectExperimentsTest.java

@@ -176,7 +176,7 @@ public class ProjectExperimentsTest extends AbstractGhidraHeadedIntegrationTest
 
 		assertNotNull(proj2 = pm.openProject(loc2, false, false));
 
-		ProjectData data1 = proj2.addProjectView(loc1.getURL());
+		ProjectData data1 = proj2.addProjectView(loc1.getURL(), true);
 		assertNotNull(data1);
 
 		// It's a cryin' shame. I don't get *any* callbacks. _ANY!_

Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/DBTraceContentHandler.java

@@ -18,11 +18,13 @@ package ghidra.trace.database;
 import java.io.IOException;
 
 import javax.swing.Icon;
+import javax.swing.ImageIcon;
 
 import db.DBHandle;
 import db.buffers.BufferFile;
 import db.buffers.ManagedBufferFile;
-import ghidra.framework.data.*;
+import ghidra.framework.data.DBWithUserDataContentHandler;
+import ghidra.framework.data.DomainObjectMergeManager;
 import ghidra.framework.model.ChangeSet;
 import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.*;
@@ -34,9 +36,16 @@ import ghidra.util.exception.CancelledException;
 import ghidra.util.exception.VersionException;
 import ghidra.util.task.TaskMonitor;
 
-public class DBTraceContentHandler extends DBContentHandler {
+public class DBTraceContentHandler extends DBWithUserDataContentHandler<DBTrace> {
 	public static final String TRACE_CONTENT_TYPE = "Trace";
 
+	public static ImageIcon TRACE_ICON = Trace.TRACE_ICON;
+
+	static final Class<DBTrace> TRACE_DOMAIN_OBJECT_CLASS = DBTrace.class;
+	static final String TRACE_CONTENT_DEFAULT_TOOL = "Debugger";
+
+	private static final DBTraceLinkContentHandler linkHandler = new DBTraceLinkContentHandler();
+
 	@Override
 	public long createFile(FileSystem fs, FileSystem userfs, String path, String name,
 			DomainObject obj, TaskMonitor monitor)
@@ -48,7 +57,7 @@ public class DBTraceContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public DomainObjectAdapter getImmutableObject(FolderItem item, Object consumer, int version,
+	public DBTrace getImmutableObject(FolderItem item, Object consumer, int version,
 			int minChangeVersion, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException {
 		String contentType = item.getContentType();
@@ -96,7 +105,7 @@ public class DBTraceContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public DomainObjectAdapter getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
+	public DBTrace getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
 			Object consumer, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
 		String contentType = item.getContentType();
@@ -146,7 +155,7 @@ public class DBTraceContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public DomainObjectAdapter getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
+	public DBTrace getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
 			boolean okToUpgrade, boolean recover, Object consumer, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException {
 		String contentType = item.getContentType();
@@ -296,8 +305,8 @@ public class DBTraceContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public Class<? extends DomainObject> getDomainObjectClass() {
+	public Class<DBTrace> getDomainObjectClass() {
-		return DBTrace.class;
+		return TRACE_DOMAIN_OBJECT_CLASS;
 	}
 
 	@Override
@@ -312,12 +321,12 @@ public class DBTraceContentHandler extends DBContentHandler {
 
 	@Override
 	public String getDefaultToolName() {
-		return "Debugger";
+		return TRACE_CONTENT_DEFAULT_TOOL;
 	}
 
 	@Override
 	public Icon getIcon() {
-		return Trace.TRACE_ICON;
+		return TRACE_ICON;
 	}
 
 	@Override
@@ -331,4 +340,9 @@ public class DBTraceContentHandler extends DBContentHandler {
 		// TODO:
 		return null;
 	}
+
+	@Override
+	public DBTraceLinkContentHandler getLinkHandler() {
+		return linkHandler;
+	}
 }

Ghidra/Debug/Framework-TraceModeling/src/main/java/ghidra/trace/database/DBTraceLinkContentHandler.java

@@ -0,0 +1,71 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.trace.database;
+
+import java.io.IOException;
+
+import javax.swing.Icon;
+
+import ghidra.framework.data.LinkHandler;
+import ghidra.framework.data.URLLinkObject;
+import ghidra.framework.model.DomainObject;
+import ghidra.framework.store.FileSystem;
+import ghidra.util.InvalidNameException;
+import ghidra.util.exception.CancelledException;
+import ghidra.util.task.TaskMonitor;
+
+public class DBTraceLinkContentHandler extends LinkHandler<DBTrace> {
+
+	public static final String TRACE_LINK_CONTENT_TYPE = "TraceLink";
+
+	@Override
+	public long createFile(FileSystem fs, FileSystem userfs, String path, String name,
+			DomainObject obj, TaskMonitor monitor)
+			throws IOException, InvalidNameException, CancelledException {
+		if (!(obj instanceof URLLinkObject)) {
+			throw new IOException("Unsupported domain object: " + obj.getClass().getName());
+		}
+		return createFile((URLLinkObject) obj, TRACE_LINK_CONTENT_TYPE, fs, path, name,
+			monitor);
+	}
+
+	@Override
+	public String getContentType() {
+		return TRACE_LINK_CONTENT_TYPE;
+	}
+
+	@Override
+	public String getContentTypeDisplayString() {
+		return TRACE_LINK_CONTENT_TYPE;
+	}
+
+	@Override
+	public Class<DBTrace> getDomainObjectClass() {
+		// return linked content class
+		return DBTraceContentHandler.TRACE_DOMAIN_OBJECT_CLASS;
+	}
+
+	@Override
+	public Icon getIcon() {
+		return DBTraceContentHandler.TRACE_ICON;
+	}
+
+	@Override
+	public String getDefaultToolName() {
+		return DBTraceContentHandler.TRACE_CONTENT_DEFAULT_TOOL;
+	}
+
+}

Ghidra/Features/Base/certification.manifest

@@ -351,6 +351,7 @@ src/main/help/help/topics/FrontEndPlugin/images/DeleteProject.png||GHIDRA||||END
 src/main/help/help/topics/FrontEndPlugin/images/EditPluginPath.png||GHIDRA||||END|
 src/main/help/help/topics/FrontEndPlugin/images/EditProjectAccessList.png||GHIDRA||||END|
 src/main/help/help/topics/FrontEndPlugin/images/EditProjectAccessPanel.png||GHIDRA||||END|
+src/main/help/help/topics/FrontEndPlugin/images/LinkOtherProject.png||GHIDRA||||END|
 src/main/help/help/topics/FrontEndPlugin/images/MemoryUsage.png||GHIDRA||||END|
 src/main/help/help/topics/FrontEndPlugin/images/NonSharedProjectInfo.png||GHIDRA||||END|
 src/main/help/help/topics/FrontEndPlugin/images/OpenProject.png||GHIDRA||||END|
@@ -1089,7 +1090,6 @@ src/main/resources/images/layout_add.png||FAMFAMFAM Icons - CC 2.5|||famfamfam s
 src/main/resources/images/ledgreen.png||Nuvola Icons - LGPL 2.1|||Nuvola icon set|END|
 src/main/resources/images/ledred.png||Nuvola Icons - LGPL 2.1|||Nuvola icon set|END|
 src/main/resources/images/ledyellow.png||Nuvola Icons - LGPL 2.1|||Nuvola icon set|END|
-src/main/resources/images/link.png||Nuvola Icons - LGPL 2.1|||Nuvola icon set|END|
 src/main/resources/images/lock.gif||GHIDRA||||END|
 src/main/resources/images/magnifier.png||FAMFAMFAM Icons - CC 2.5||||END|
 src/main/resources/images/media-flash.png||Oxygen Icons - LGPL 3.0|||Oxygen icon theme (dual license; LGPL or CC-SA-3.0)|END|

Ghidra/Features/Base/ghidra_scripts/CallAnotherScriptForAllPrograms.java

@@ -17,6 +17,8 @@
 // NOTE: Script will only process unversioned and checked-out files.
 //@category Examples
 
+import java.io.IOException;
+
 import ghidra.app.script.GhidraScript;
 import ghidra.app.script.GhidraState;
 import ghidra.framework.model.*;
@@ -25,8 +27,6 @@ import ghidra.program.model.listing.Program;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.exception.VersionException;
 
-import java.io.IOException;
-
 public class CallAnotherScriptForAllPrograms extends GhidraScript {
 
 	// The script referenced in the following line should be replaced with the script to be called
@@ -59,6 +59,10 @@ public class CallAnotherScriptForAllPrograms extends GhidraScript {
 	}
 
 	private void processDomainFile(DomainFile domainFile) throws CancelledException, IOException {
+		// Do not follow folder-links or consider program links.  Using content type
+		// to filter is best way to control this.  If program links should be considered
+		// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+		// should be used.
 		if (!ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(domainFile.getContentType())) {
 			return; // skip non-Program files
 		}

Ghidra/Features/Base/ghidra_scripts/RepositoryFileUpgradeScript.java

@@ -143,6 +143,8 @@ public class RepositoryFileUpgradeScript extends GhidraScript {
 	}
 
 	private boolean performProgramUpgrade(DomainFile df) throws IOException, CancelledException {
+		// Do not follow folder-links or consider program links.  Using content type
+		// to filter is best way to control this.
 		if (!ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(df.getContentType())) {
 			return false;
 		}

Ghidra/Features/Base/ghidra_scripts/VersionControl_AddAll.java

@@ -48,7 +48,10 @@ public class VersionControl_AddAll extends GhidraScript {
 			if (monitor.isCancelled()) {
 				break;
 			}
-
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.  It may also be appropriate to handle other content types.
 			if (!ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(file.getContentType()) ||
 				file.isVersioned()) {
 				continue;// skip

Ghidra/Features/Base/src/main/help/help/topics/Annotations/Annotations.html

@@ -22,13 +22,15 @@
     hyperlink.</P>
     <!-- Annotation Example -->
 
-    <P>The following text shows the syntax of the URL annotation:</P>
+    <P>The following text shows the syntax of a sample URL annotation:</P>
 	<pre><font size="4"><br>
-	<b>{@<i>url</i></b> "http://www.google.com"<b>}</b><br>
+	<b>{@<i>url</i></b> "<i>http://www.google.com</i>"</b> "Search Web"<b>}</b><br>
 	</font><br></pre>
 
     <P>The bold text is required for all annotations. The italicized text is required but is
-    specific to the annotation being used (see the table below).</P>
+    specific to the annotation being used (see the table below).  The optional rendered display text
+    "Search Web" will be displayed in listing.  If the optional display test is omitted, the URL 
+    will be displayed.  Quotes around display text are optional.</P>
 
     <H2>Examples</H2>
 
@@ -47,10 +49,21 @@
        <I>Rendered URL Annotation Example</I></P>
 
       <P>When the URL text (e.g., "http://www.google.com") in the above image is clicked from within
-      Ghidra, a web browser is launched and attempts to load the corresponding web page.  If the URL text
+      Ghidra, a web browser is launched and attempts to load the corresponding web page.  </P>
-      is of the form <i>ghidra://&lt;host&gt;[:&lt;port&gt;]/&lt;repository-name&gt;/&lt;program-path&gt;[#&lt;address-or-symbol-ref&gt;]</i>
+      
-      an attempt will be made to open the corresponding program from the referenced Ghidra Server (e.g., 
+      <P>If the URL text corresponds to a Ghidra URL and attempt will be made to open the referenced
-      <i>ghidra://myserver/Repo/notepad.exe#entry</i>).</P>
+      Program file within the Code Browser.  Such a URL may refer to a Program file from a 
+      local project or Ghidra Server.  The Ghidra URL forms supported include:</P>
+      
+      <P><U>Remote Ghidra Server file</U><BR>
+      <i>ghidra://&lt;host&gt;[:&lt;port&gt;]/&lt;repository-name&gt;/&lt;program-path&gt;[#&lt;address-or-symbol-ref&gt;]</i><BR>
+      Example: <i>ghidra://hostname/Repo/notepad.exe#entry</i>
+      </P>
+      
+      <P><U>Local Ghidra project file</U><BR>
+      <i>ghidra:/[&lt;project-path&gt/]&lt;project-name&gt;?/&lt;program-path&gt;[#&lt;address-or-symbol-ref&gt;]</i><BR>
+      Example: <i>ghidra:/share/MyProject?/notepad.exe#entry</i>
+      </P>
     </BLOCKQUOTE>
 
     <H2>Valid Annotations</H2>
@@ -174,9 +187,10 @@
             <TD valign="top" width="15%">Displays the given URL has a hyperlink. This annotation
             optionally takes display text so that the hyperlink may be displayed with text other
             than that of the URL.<BR><BR>
-            References to <i>ghidra://</i>, which refer to a program within a Ghidra Server repository,
+            References to a program file on a Ghidra Server (<i>ghidra://&lt;host...</i>) or 
-            will be opened within the Listing display, while all other URL protocols (e.g., <i>http://, https://,
+            local project (<i>ghidra:/&lt;project-...</i>) will be opened within the Listing display, 
-            file://,</i> etc.) will be launched via an external web browser (see 
+            while all other URL forms (e.g., <i>http://, https://, file://,</i> etc.) will be 
+            launched via an external web browser (see 
             <a href="help/topics/ShowInstructionInfoPlugin/ShowInstructionInfo.htm#Show_Processor_Manual">command configuration 
             for Processor Manuals</a>). 
             </TD>
@@ -216,6 +230,12 @@
                 <LI>{@url "ghidra://myserver/Repo/notepad.exe#entry"}</LI>
                 
                 <LI>{@url "ghidra://myserver/Repo/notepad.exe" "see notepad.exe"}</LI>
+                
+                <LI>{@url "ghidra:/share/MyProject?/notepad.exe#entry"}</LI>
+                
+                <LI>{@url "ghidra:/share/MyProject?/notepad.exe" "see notepad.exe"}</LI>
+                
+                
               </UL>
             </TD>
           </TR>
@@ -224,8 +244,9 @@
             <TD valign="top" width="5%">Program<BR>
             </TD>
 
-            <TD valign="top" width="15%">Displays a hyperlink to the given Ghidra program name that
+            <TD valign="top" width="15%">Displays a hyperlink to the given Ghidra program pathname 
-            will open that program in a new Listing tab when clicked.<BR>
+            with the current project.  Referenced program 
+            will open in a new Listing tab when clicked.<BR>
              You may optionally provide an address or symbol to be displayed when the program is
             opened by appending to the program name an '@' character, followed by an address or
             symbol name.</TD>

Ghidra/Features/Base/src/main/help/help/topics/FrontEndPlugin/Ghidra_Front_end.htm

@@ -688,6 +688,54 @@
 
         <P>The tabbed pane for read-only Project data is removed from the Project Window.</P>
       </BLOCKQUOTE>
+      
+      <H3><A name="Create_File_Links"></A>Create Linked Folder or File</H3>
+      
+      <BLOCKQUOTE>
+        <P>This feature allows you to create a folder or file link in your active project to a 
+        corresponding folder or file within a read-only viewed project.  
+        This is done using a Ghidra URL which references the 
+        file in its local or remote storage location.  If the viewed project corresponds to a 
+        viewed repository a remote URL will be used, while other cases will refer to the
+        locally viewed project.  It is possible for links to become broken if the referenced
+        repository, local project or file location are changed.</P>
+        <ol>
+        <li>Select a single folder or file from a viewed READ-ONLY Project Data tree.</li>
+        <li>Right mouse click on the selected tree node and choose the <I>Copy</I> option.</li>
+        <li>Select a destination folder in the active project tree.</li>
+        <li>Right mouse click on the folder and choose the <I>Paste as Link</I> option.
+            <P><IMG src="../../shared/note.png" border="0">Currently, linked-file types are 
+            currently limited to <I>Program</I> and <I>Data Type Archive</I> files 
+            only.  The <I>Past as Link</I> menu item will be disabled for 
+            unsupported file content types or for other unsupported situations such as internal 
+            linking within the same project.</P>
+            </li>
+        </ol>
+        <P>A linked-file may be opened in a tool via the project window in the same fashion that 
+        a normal file is opened (e.g., double-left-mouse-click or drag-n-drop onto a tool box icon).
+        Such a project file may also be opened within a Tool using its <B>File->Open...</B> action
+        and selected from the resulting project file selection dilaog.
+        Clicking on a linked-folder in the active project window will open that location in a
+        <B>READ-ONLY Project Data</B> tree.  The user may be prompted for a shared repository
+        connection password when accessing a linked folder or file.</P>
+        <P>Within a project file chooser dialog a linked-folder may be expanded in a similar fashion
+        to local folders provided any neccessary repository connection can be completed.</P>
+        <P><IMG src="../../shared/note.png" border="0"><B>Add to Version Control...</B> is supported
+        for repository folder and file links only and will be disabled for links to a 
+        local project.</P>
+        <P><IMG src="../../shared/note.png" border="0">Currently, linked-files only provide access
+        to the latest file version and do not facilitate access to older file versions.</P>
+        <P>The project window below shows a Program file-link "Program1" which is linked to the
+        same file in the viewed project.  Hovering the mouse over a linked-file will show the URL 
+        of the linked file or folder.  The chain-link icon decoration indicates such a linked 
+        file or folder.</P>
+        
+        <CENTER>
+          <IMG src= "images/LinkOtherProject.png" border="0">
+        </CENTER>
+        
+      </BLOCKQUOTE>
+      
     </BLOCKQUOTE>
 
     <H2><A name="Workspace"></A>Workspaces</H2>

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/calltree/CallTreeProvider.java

@@ -1266,19 +1266,24 @@ public class CallTreeProvider extends ComponentProviderAdapter implements Domain
 		}
 
 		@Override
-		protected void expandNode(GTreeNode node, TaskMonitor monitor) throws CancelledException {
+		protected void expandNode(GTreeNode node, boolean force, TaskMonitor monitor)
+				throws CancelledException {
 			TreePath treePath = node.getTreePath();
 			Object[] path = treePath.getPath();
 			if (path.length > maxDepth) {
 				return;
 			}
 
+			if (!force && !node.isAutoExpandPermitted()) {
+				return;
+			}
+
 			CallNode callNode = (CallNode) node;
 			if (callNode.functionIsInPath()) {
 				return; // this path hit a function that is already in the path
 			}
 
-			super.expandNode(node, monitor);
+			super.expandNode(node, false, monitor);
 		}
 	}
 

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/clear/ClearFlowAndRepairCmd.java

@@ -106,9 +106,33 @@ public class ClearFlowAndRepairCmd extends BackgroundCommand {
 				CodeUnit cu = cuIter.next();
 				if (cu instanceof Instruction) {
 					Instruction instr = (Instruction) cu;
+
+					// check for function on delay slot
+					if (listing.getFunctionAt(instr.getMinAddress()) != null) {
+						continue; // skip since it will be picked-up by flow if appropriate
+					}
+
+					// check for fallthrough to instruction
 					Address ffAddr = instr.getFallFrom();
 					if (ffAddr != null && startAddrs.contains(ffAddr)) {
-						continue; // skip since it will be picked-up by flow
+						continue; // skip since it will be picked-up by flow if appropriate
+					}
+
+					// check for flow into delay slot
+					if (instr.isInDelaySlot()) {
+						boolean skip = false;
+						ReferenceIterator refToIter = instr.getReferenceIteratorTo();
+						while (refToIter.hasNext()) {
+							Reference ref = refToIter.next();
+							RefType refType = ref.getReferenceType();
+							if (refType.isJump() || refType.isCall()) {
+								skip = true;
+								break;
+							}
+						}
+						if (skip) {
+							continue; // skip since it will be picked-up by flow if appropriate
+						}
 					}
 				}
 				else {

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/comments/CommentsDialog.java

@@ -240,10 +240,11 @@ public class CommentsDialog extends DialogComponentProvider implements KeyListen
 	////////////////////////////////////////////////////////////////////
 
 	private AnnotationAdapterWrapper[] getAnnotationAdapterWrappers() {
-		AnnotatedStringHandler[] annotations = Annotation.getAnnotatedStringHandlers();
+		List<AnnotatedStringHandler> annotations = Annotation.getAnnotatedStringHandlers();
-		AnnotationAdapterWrapper[] retVal = new AnnotationAdapterWrapper[annotations.length];
+		int count = annotations.size();
-		for (int i = 0; i < annotations.length; i++) {
+		AnnotationAdapterWrapper[] retVal = new AnnotationAdapterWrapper[count];
-			retVal[i] = new AnnotationAdapterWrapper(annotations[i]);
+		for (int i = 0; i < count; i++) {
+			retVal[i] = new AnnotationAdapterWrapper(annotations.get(i));
 		}
 		return retVal;
 	}

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/DataTypeManagerPlugin.java

@@ -56,7 +56,6 @@ import ghidra.framework.options.SaveState;
 import ghidra.framework.plugintool.PluginInfo;
 import ghidra.framework.plugintool.PluginTool;
 import ghidra.framework.plugintool.util.PluginStatus;
-import ghidra.program.database.DataTypeArchiveContentHandler;
 import ghidra.program.database.data.ProgramDataTypeManager;
 import ghidra.program.model.address.AddressSetView;
 import ghidra.program.model.data.*;
@@ -245,8 +244,7 @@ public class DataTypeManagerPlugin extends ProgramPlugin
 		Project project = tool.getProjectManager().getActiveProject();
 		if (project != null && project.getName().equals(projectName)) {
 			DomainFile df = project.getProjectData().getFile(pathname);
-			if (df != null && DataTypeArchiveContentHandler.DATA_TYPE_ARCHIVE_CONTENT_TYPE
+			if (DataTypeArchive.class.isAssignableFrom(df.getDomainObjectClass())) {
-					.equals(df.getContentType())) {
 				return df;
 			}
 		}
@@ -588,12 +586,9 @@ public class DataTypeManagerPlugin extends ProgramPlugin
 					openArchive(domainFile, version);
 				}
 			};
-			DomainFileFilter filter = f -> {
-				Class<?> c = f.getDomainObjectClass();
-				return DataTypeArchive.class.isAssignableFrom(c);
-			};
 			openDialog =
-				new OpenVersionedFileDialog(tool, "Open Project Data Type Archive", filter);
+				new OpenVersionedFileDialog(tool, "Open Project Data Type Archive",
+					df -> DataTypeArchive.class.isAssignableFrom(df.getDomainObjectClass()));
 			openDialog.setHelpLocation(new HelpLocation(HelpTopics.PROGRAM, "Open_File_Dialog"));
 			openDialog.addOkActionListener(listener);
 		}

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/DataTypesProvider.java

@@ -608,8 +608,15 @@ public class DataTypesProvider extends ComponentProviderAdapter {
 		ArchiveNode archiveNode = dataTypeNode.getArchiveNode();
 
 		if (archiveNode instanceof ProjectArchiveNode && !archiveNode.isModifiable()) {
+			ProjectArchiveNode projectArchive = (ProjectArchiveNode) archiveNode;
+			if (projectArchive.getDomainFile().isReadOnly()) {
+				Msg.showInfo(getClass(), archiveGTree, "Read-Only Archive",
+					"You may not edit data type within a read-only project archive.");
+			}
+			else {
 				Msg.showInfo(getClass(), archiveGTree, "Archive Not Checked Out",
 					"You must checkout this archive before you may edit data types.");
+			}
 			return;
 		}
 

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/actions/associate/AssociateDataTypeAction.java

@@ -38,6 +38,7 @@ import ghidra.app.plugin.core.datamgr.tree.ArchiveNode;
 import ghidra.app.plugin.core.datamgr.tree.DataTypeNode;
 import ghidra.app.plugin.core.datamgr.util.DataTypeTreeCopyMoveTask;
 import ghidra.app.plugin.core.datamgr.util.DataTypeTreeCopyMoveTask.ActionType;
+import ghidra.app.plugin.core.datamgr.util.DataTypeUtils;
 import ghidra.program.model.data.*;
 import ghidra.util.Msg;
 import ghidra.util.layout.PairLayout;
@@ -85,26 +86,21 @@ public class AssociateDataTypeAction extends DockingAction {
 		return !nodes.isEmpty();
 	}
 
-	private boolean hasSingleModifiableSourceArchive(List<GTreeNode> nodes) {
+	private Archive getSingleDTArchive(List<GTreeNode> nodes) {
 
-		Archive sourceArchive = null;
+		Archive dtArchive = null;
 		for (GTreeNode node : nodes) {
 			Archive archive = findArchive(node);
-			if (sourceArchive == null) {
+			if (dtArchive == null) {
-				sourceArchive = archive;
+				dtArchive = archive;
 				continue;
 			}
 
-			if (sourceArchive != archive) {
+			if (dtArchive != archive) {
-				return false;
+				return null;
 			}
 		}
-
+		return dtArchive;
-		if (sourceArchive != null && sourceArchive.isModifiable()) {
-			return true;
-		}
-
-		return false;
 	}
 
 	private static Archive findArchive(GTreeNode node) {
@@ -134,13 +130,20 @@ public class AssociateDataTypeAction extends DockingAction {
 
 		List<GTreeNode> nodes = ((DataTypesActionContext) context).getSelectedNodes();
 
-		if (!hasSingleModifiableSourceArchive(nodes)) {
+		Archive dtArchive = getSingleDTArchive(nodes);
-			Msg.showInfo(this, getProviderComponent(), "Multiple Source Archives",
+		if (dtArchive == null) {
+			Msg.showInfo(this, getProviderComponent(), "Multiple Data Type Archives",
 				"The currently selected nodes are from multiple archives.\n" +
 					"Please select only nodes from a single archvie.");
 			return;
 		}
 
+		if (!dtArchive.isModifiable()) {
+			DataTypeUtils.showUnmodifiableArchiveErrorMessage(context.getSourceComponent(),
+				"Disassociate Failed", dtArchive.getDataTypeManager());
+			return;
+		}
+
 		if (isAlreadyAssociated((DataTypesActionContext) context)) {
 			Msg.showInfo(this, getProviderComponent(), "Already Associated",
 				"One or more of the currently selected nodes are already associated\n" +

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/archive/DataTypeManagerHandler.java

@@ -76,7 +76,7 @@ public class DataTypeManagerHandler {
 	private DataTreeDialog dataTreeSaveDialog;
 	private CreateDataTypeArchiveDataTreeDialog dataTreeCreateDialog;
 	private boolean treeDialogCancelled = false;
-	private DomainFileFilter domainFileFilter;
+	private DomainFileFilter createArchiveFileFilter;
 
 	private DataTypeIndexer dataTypeIndexer;
 	private List<ArchiveManagerListener> archiveManagerlisteners = new ArrayList<>();
@@ -102,9 +102,17 @@ public class DataTypeManagerHandler {
 		dataTypeIndexer.addDataTypeManager(builtInDataTypesManager);
 		openArchives.add(new BuiltInArchive(this, builtInDataTypesManager));
 
-		domainFileFilter = f -> {
+		createArchiveFileFilter = new DomainFileFilter() {
-			Class<?> c = f.getDomainObjectClass();
+
-			return DataTypeArchive.class.isAssignableFrom(c);
+			@Override
+			public boolean accept(DomainFile df) {
+				return DataTypeArchive.class.isAssignableFrom(df.getDomainObjectClass());
+			}
+
+			@Override
+			public boolean followLinkedFolders() {
+				return false;
+			}
 		};
 
 		folderListener = new MyFolderListener();
@@ -1425,7 +1433,7 @@ public class DataTypeManagerHandler {
 				}
 			};
 			dataTreeSaveDialog =
-				new DataTreeDialog(null, "Save As", DataTreeDialog.SAVE, domainFileFilter);
+				new DataTreeDialog(null, "Save As", DataTreeDialog.SAVE, createArchiveFileFilter);
 
 			dataTreeSaveDialog.addOkActionListener(listener);
 			dataTreeSaveDialog
@@ -1465,7 +1473,7 @@ public class DataTypeManagerHandler {
 			};
 
 			dataTreeCreateDialog = new CreateDataTypeArchiveDataTreeDialog(null, "Create",
-				DataTreeDialog.CREATE, domainFileFilter);
+				DataTreeDialog.CREATE, createArchiveFileFilter);
 
 			dataTreeCreateDialog.addOkActionListener(listener);
 			dataTreeCreateDialog.setHelpLocation(

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/datamgr/util/DataTypeUtils.java

@@ -24,6 +24,7 @@ import javax.swing.Icon;
 import generic.theme.GColor;
 import generic.theme.GIcon;
 import ghidra.app.services.DataTypeQueryService;
+import ghidra.program.database.data.ProjectDataTypeManager;
 import ghidra.program.model.data.*;
 import ghidra.program.model.data.Enum;
 import ghidra.util.Msg;
@@ -438,10 +439,19 @@ public class DataTypeUtils {
 			msg = "The archive file is not modifiable!\nYou must open the archive for editing\n" +
 				"before performing this operation.\n" + dtm.getName();
 		}
+		else if (dtm instanceof ProjectDataTypeManager) {
+			ProjectDataTypeManager projectDtm = (ProjectDataTypeManager) dtm;
+			if (!projectDtm.isUpdatable() && !projectDtm.getDomainFile().canCheckout()) {
+				msg = "The project archive is not modifiable!\n" + dtm.getName();
+			}
 			else {
 				msg = "The project archive is not modifiable!\nYou must check out the archive\n" +
 					"before performing this operation.\n" + dtm.getName();
 			}
+		}
+		else {
+			msg = "The Archive is not modifiable!\n";
+		}
 		Msg.showInfo(DataTypeUtils.class, parent, title, msg);
 	}
 }

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/exporter/ExporterDialog.java

@@ -295,11 +295,15 @@ public class ExporterDialog extends DialogComponentProvider implements AddressFa
 		return comboBox;
 	}
 
+	@SuppressWarnings("unchecked")
 	private List<Exporter> getApplicableExporters() {
 		List<Exporter> list = new ArrayList<>(ClassSearcher.getInstances(Exporter.class));
-		Class<? extends DomainObject> domainObjectClass = domainFile.getDomainObjectClass();
+		Class<?> domainObjectClass = domainFile.getDomainObjectClass();
-		list.removeIf(exporter -> !exporter.canExportDomainObject(domainObjectClass));
+		if (DomainObject.class.isAssignableFrom(domainObjectClass)) {
+			list.removeIf(exporter -> !exporter
+					.canExportDomainObject((Class<? extends DomainObject>) domainObjectClass));
 			Collections.sort(list, (o1, o2) -> o1.toString().compareTo(o2.toString()));
+		}
 		return list;
 	}
 
@@ -422,8 +426,16 @@ public class ExporterDialog extends DialogComponentProvider implements AddressFa
 
 	private void doOpenFile(TaskMonitor monitor) {
 		try {
-			domainObject = domainFile.getImmutableDomainObject(this, DomainFile.DEFAULT_VERSION,
+			if (domainFile.isLinkFile()) {
-				TaskMonitor.DUMMY);
+				// Linked files are always subject to upgrade if needed and do not support
+				// getImmutableDomainObject
+				domainObject =
+					domainFile.getReadOnlyDomainObject(this, DomainFile.DEFAULT_VERSION, monitor);
+			}
+			else {
+				domainObject =
+					domainFile.getImmutableDomainObject(this, DomainFile.DEFAULT_VERSION, monitor);
+			}
 		}
 		catch (VersionException | CancelledException | IOException e) {
 			Msg.showError(this, getComponent(), "Error Opening File",

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/misc/MyProgramChangesDisplayPlugin.java

@@ -147,7 +147,8 @@ public class MyProgramChangesDisplayPlugin extends ProgramPlugin implements Doma
 
 			@Override
 			public boolean isEnabledForContext(ActionContext context) {
-				return currentProgram != null && currentProgram.getDomainFile().canCheckin();
+				return currentProgram != null &&
+					currentProgram.getDomainFile().modifiedSinceCheckout();
 			}
 		};
 

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/processors/LanguageProviderPlugin.java

@@ -26,8 +26,8 @@ import docking.action.MenuData;
 import docking.widgets.OptionDialog;
 import ghidra.app.CorePluginPackage;
 import ghidra.app.plugin.PluginCategoryNames;
-import ghidra.framework.main.FrontEndTool;
 import ghidra.framework.main.ApplicationLevelPlugin;
+import ghidra.framework.main.FrontEndTool;
 import ghidra.framework.main.datatable.ProjectDataContext;
 import ghidra.framework.model.*;
 import ghidra.framework.plugintool.*;
@@ -316,18 +316,20 @@ public final class LanguageProviderPlugin extends Plugin implements ApplicationL
 			try {
 				SwingUtilities.invokeAndWait(() -> {
 					ToolServices toolServices = tool.getToolServices();
-					String defaultToolName = toolServices.getDefaultToolTemplate(file).getName();
+					ToolTemplate defaultToolTemplate = toolServices.getDefaultToolTemplate(file);
+					if (defaultToolTemplate != null) {
+						String defaultToolName = defaultToolTemplate.getName();
 						for (PluginTool t : toolServices.getRunningTools()) {
 							if (t.getName().equals(defaultToolName)) {
 								openTool = t;
 								break;
 							}
 						}
-					if (openTool != null) {
-						openTool.acceptDomainFiles(new DomainFile[] { file });
 					}
-					else {
+					if (openTool == null ||
-						openTool = tool.getToolServices().launchDefaultTool(file);
+						!openTool.acceptDomainFiles(new DomainFile[] { file })) {
+						Msg.showError(this, tool.getToolFrame(), "Failed to Open Program",
+							"A suitable default tool could not found!");
 					}
 				});
 			}
@@ -336,7 +338,7 @@ public final class LanguageProviderPlugin extends Plugin implements ApplicationL
 			}
 			catch (InvocationTargetException e) {
 				Throwable t = e.getCause();
-				Msg.showError(this, tool.getToolFrame(), "Tool Launch Failed",
+				Msg.showError(this, tool.getToolFrame(), "Failed to Open Program",
 					"An error occurred while attempting to launch your default tool!", t);
 			}
 		}

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/MultiProgramManager.java

@@ -30,6 +30,7 @@ import ghidra.app.events.*;
 import ghidra.app.nav.Navigatable;
 import ghidra.app.services.*;
 import ghidra.app.util.task.OpenProgramTask;
+import ghidra.app.util.task.OpenProgramTask.OpenProgramRequest;
 import ghidra.framework.data.DomainObjectAdapterDB;
 import ghidra.framework.model.*;
 import ghidra.framework.plugintool.PluginTool;
@@ -42,9 +43,6 @@ import ghidra.util.task.TaskLauncher;
 
 class MultiProgramManager implements DomainObjectListener, TransactionListener {
 
-	// arbitrary counter for given ProgramInfo objects and ID to use for sorting
-	private static final AtomicInteger nextAvailableId = new AtomicInteger();
-
 	private ProgramManagerPlugin plugin;
 	private PluginTool tool;
 	private ProgramInfo currentInfo;
@@ -82,26 +80,32 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 		};
 	}
 
-	void addProgram(Program p, URL ghidraURL, int state) {
+	void addProgram(Program p, DomainFile domainFile, int state) {
+		addProgram(new ProgramInfo(p, domainFile, state != ProgramManager.OPEN_HIDDEN), state);
+	}
+
+	void addProgram(Program p, URL ghidraUrl, int state) {
+		addProgram(new ProgramInfo(p, ghidraUrl, state != ProgramManager.OPEN_HIDDEN), state);
+	}
+
+	private void addProgram(ProgramInfo programInfo, int state) {
+		Program p = programInfo.program;
 		ProgramInfo oldInfo = getInfo(p);
 		if (oldInfo == null) {
+			oldInfo = programInfo;
 			p.addConsumer(tool);
-			ProgramInfo info = new ProgramInfo(p, state != ProgramManager.OPEN_HIDDEN);
+			openPrograms.add(oldInfo);
-			info.ghidraURL = ghidraURL;
-			openPrograms.add(info);
 			openPrograms.sort(Comparator.naturalOrder());
-			programMap.put(p, info);
+			programMap.put(p, oldInfo);
 
 			fireOpenEvents(p);
 
 			p.addListener(this);
 			p.addTransactionListener(this);
 		}
-		else {
+		else if (!oldInfo.visible && state != ProgramManager.OPEN_HIDDEN) {
-			if (!oldInfo.visible && state != ProgramManager.OPEN_HIDDEN) {
 			oldInfo.setVisible(true);
 		}
-		}
 		if (state == ProgramManager.OPEN_CURRENT) {
 			saveLocation();
 			setCurrentProgram(p);
@@ -246,12 +250,7 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 		TransientToolState toolState = null;
 		if (currentInfo != null) {
 			currentInfo.setVisible(true);
-			DomainFile df = currentInfo.program.getDomainFile();
+			tool.setSubTitle(currentInfo.toString());
-			String title = df.toString();
-			if (df.isReadOnly()) {
-				title = title + " [Read-Only]";
-			}
-			tool.setSubTitle(title);
 			txMonitor.setProgram(currentInfo.program);
 			if (currentInfo.lastState != null) {
 				toolState = currentInfo.lastState;
@@ -370,7 +369,7 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 		return (info != null && info.owner != null);
 	}
 
-	private ProgramInfo getInfo(Program p) {
+	ProgramInfo getInfo(Program p) {
 		if (p == null) {
 			return null;
 		}
@@ -378,9 +377,6 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 	}
 
 	Program getOpenProgram(URL ghidraURL) {
-		if (!GhidraURL.isServerRepositoryURL(ghidraURL)) {
-			return null;
-		}
 		URL normalizedURL = GhidraURL.getNormalizedURL(ghidraURL);
 		for (ProgramInfo info : programMap.values()) {
 			URL url = info.ghidraURL;
@@ -392,10 +388,10 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 	}
 
 	Program getOpenProgram(DomainFile domainFile, int version) {
-		for (Program program : programMap.keySet()) {
+		for (ProgramInfo info : programMap.values()) {
-			DomainFile programDomainFile = program.getDomainFile();
+			DomainFile df = info.domainFile;
-			if (filesMatch(domainFile, version, programDomainFile)) {
+			if (df != null && filesMatch(domainFile, version, df)) {
-				return program;
+				return info.program;
 			}
 		}
 		return null;
@@ -413,7 +409,7 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 		if (!SystemUtilities.isEqual(file1.getProjectLocator(), file2.getProjectLocator())) {
 			return false;
 		}
-
+		// TODO: version check is questionable - unclear how proxy file would work
 		int openVersion = file2.isReadOnly() ? file2.getVersion() : -1;
 		return version == openVersion;
 	}
@@ -488,28 +484,54 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 			OpenProgramTask openTask = new OpenProgramTask(file, -1, this);
 			openTask.setSilent();
 			new TaskLauncher(openTask, tool.getToolFrame());
-			Program openProgram = openTask.getOpenProgram();
+			OpenProgramRequest openProgramReq = openTask.getOpenProgram();
-			plugin.openProgram(openProgram,
+			if (openProgramReq != null) {
+				plugin.openProgram(openProgramReq.getProgram(),
 					dataState != null ? ProgramManager.OPEN_CURRENT : ProgramManager.OPEN_VISIBLE);
-			openProgram.release(this);
+				openProgramReq.release();
 				removeProgram((Program) oldObject);
 				if (dataState != null) {
 					tool.restoreDataStateFromXml(dataState);
 				}
 			}
 		}
+	}
 
-	private class ProgramInfo implements Comparable<ProgramInfo> {
+	class ProgramInfo implements Comparable<ProgramInfo> {
+
+		// arbitrary counter for given ProgramInfo objects and ID to use for sorting
+		private static final AtomicInteger nextAvailableId = new AtomicInteger();
+
+		public final Program program;
+		
+		// NOTE: domainFile and ghidraURL use are mutually exclusive and reflect how program was
+		// opened.  Supported cases include:
+		// 1. Opened via Program file
+		// 2. Opened via ProgramLink file
+		// 3. Opened via Program URL
+		
+		public final DomainFile domainFile; // may be link file
+		public final URL ghidraURL;
 
-		private Program program;
-		private URL ghidraURL;
 		private TransientToolState lastState;
 		private int instance;
-		private boolean visible;
+		private boolean visible = false;
 		private Object owner;
 
-		ProgramInfo(Program p, boolean visible) {
+		private String str; // cached toString
+
+		ProgramInfo(Program p, DomainFile domainFile, boolean visible) {
 			this.program = p;
+			this.domainFile = domainFile;
+			this.ghidraURL = null;
+			this.visible = visible;
+			instance = nextAvailableId.incrementAndGet();
+		}
+		
+		ProgramInfo(Program p, URL ghidraURL, boolean visible) {
+			this.program = p;
+			this.domainFile = null;
+			this.ghidraURL = ghidraURL;
 			this.visible = visible;
 			instance = nextAvailableId.incrementAndGet();
 		}
@@ -523,5 +545,24 @@ class MultiProgramManager implements DomainObjectListener, TransactionListener {
 		public int compareTo(ProgramInfo info) {
 			return instance - info.instance;
 		}
+
+		@Override
+		public String toString() {
+			if (str != null) {
+				return str;
+			}
+			StringBuilder buf = new StringBuilder();
+			DomainFile df = program.getDomainFile();
+			if (domainFile != null && domainFile.isLinkFile()) {
+				buf.append(domainFile.getName());
+				buf.append("->");
+			}
+			buf.append(df.toString());
+			if (df.isReadOnly()) {
+				buf.append(" [Read-Only]");
+			}
+			str = buf.toString();
+			return str;
+		}
 	}
 }

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/ProgramManagerPlugin.java

@@ -18,7 +18,6 @@ package ghidra.app.plugin.core.progmgr;
 import java.awt.Component;
 import java.awt.event.ActionListener;
 import java.beans.PropertyEditor;
-import java.io.IOException;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.ArrayList;
@@ -32,26 +31,26 @@ import ghidra.app.CorePluginPackage;
 import ghidra.app.context.ProgramActionContext;
 import ghidra.app.events.*;
 import ghidra.app.plugin.PluginCategoryNames;
+import ghidra.app.plugin.core.progmgr.MultiProgramManager.ProgramInfo;
 import ghidra.app.services.ProgramManager;
 import ghidra.app.util.HelpTopics;
 import ghidra.app.util.NamespaceUtils;
 import ghidra.app.util.task.OpenProgramTask;
+import ghidra.app.util.task.OpenProgramTask.OpenProgramRequest;
 import ghidra.framework.client.ClientUtil;
-import ghidra.framework.data.ProjectFileManager;
 import ghidra.framework.main.OpenVersionedFileDialog;
 import ghidra.framework.model.*;
 import ghidra.framework.options.*;
 import ghidra.framework.plugintool.*;
 import ghidra.framework.plugintool.util.PluginStatus;
-import ghidra.framework.protocol.ghidra.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
-import ghidra.program.database.ProgramContentHandler;
 import ghidra.program.model.address.*;
 import ghidra.program.model.listing.Program;
 import ghidra.program.model.symbol.Symbol;
 import ghidra.program.model.symbol.SymbolType;
 import ghidra.program.util.*;
 import ghidra.util.*;
-import ghidra.util.exception.NotFoundException;
+import ghidra.util.exception.AssertException;
 import ghidra.util.task.TaskLauncher;
 
 //@formatter:off
@@ -121,16 +120,21 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 			if (domainFile == null) {
 				continue;
 			}
-			if (!(Program.class.isAssignableFrom(domainFile.getDomainObjectClass()))) {
+			Class<? extends DomainObject> domainObjectClass = domainFile.getDomainObjectClass();
-				continue;
+			if (Program.class.isAssignableFrom(domainObjectClass)) {
-			}
 				filesToOpen.add(domainFile);
 			}
+		}
 		openPrograms(filesToOpen);
 
 		return !filesToOpen.isEmpty();
 	}
 
+	@Override
+	public boolean accept(URL url) {
+		return openProgram(url, OPEN_CURRENT) != null;
+	}
+
 	@Override
 	public Class<?>[] getSupportedDataTypes() {
 		return new Class[] { Program.class };
@@ -144,89 +148,53 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 			return null;
 		}
 
-		return Swing.runNow(() -> doOpenProgram(ghidraURL, state));
+		// Check for URL already open and re-use
-	}
+		URL url = GhidraURL.getNormalizedURL(ghidraURL);
-
+		Program p = programMgr.getOpenProgram(url);
-	private void messageBadProgramURL(URL ghidraURL) {
+		if (p != null) {
-		Msg.showError(this, null, "Invalid Ghidra URL",
+			showProgram(p, url, state);
-			"Ghidra URL does not reference a Ghidra Program: " + ghidraURL);
+			if (state == ProgramManager.OPEN_CURRENT) {
-	}
+				gotoProgramRef(p, ghidraURL.getRef());
-
-	protected Program doOpenProgram(URL ghidraURL, int openState) {
-		if (!GhidraURL.isServerRepositoryURL(ghidraURL)) {
-			Msg.showError(this, null, "Invalid Ghidra URL",
-				"Ghidra URL does not reference a Ghidra Program: " + ghidraURL);
-			return null;
-		}
-		Program openProgram = programMgr.getOpenProgram(ghidraURL);
-		if (openProgram != null) {
-			programMgr.addProgram(openProgram, GhidraURL.getNormalizedURL(ghidraURL), openState);
-			if (openState == ProgramManager.OPEN_CURRENT) {
-				gotoProgramRef(openProgram, ghidraURL.getRef());
 				programMgr.saveLocation();
 			}
-			contextChanged();
+			return p;
-			return openProgram;
 		}
 
-		GhidraURLWrappedContent wrappedContent = null;
+		Program program = Swing.runNow(() -> doOpenProgram(ghidraURL, state));
-		Object content = null;
+
+		if (program != null) {
+			Msg.info(this, "Opened program in " + tool.getName() + " tool: " + ghidraURL);
+		}
+		return program;
+	}
+
+	/**
+	 * Open GhidraURL which corresponds to {@code ghidra://} remote URLs which correspond to a 
+	 * repository program file.
+	 * @param ghidraURL Ghidra URL which specified Program to be opened which optional ref
+	 * @param openState open state 
+	 * @return program instance of null if open failed
+	 */
+	private Program doOpenProgram(URL ghidraURL, int openState) {
+		Program p = null;
 		try {
-			GhidraURLConnection c = (GhidraURLConnection) ghidraURL.openConnection();
+			URL url = GhidraURL.getNormalizedURL(ghidraURL);
-			Object obj = c.getContent();
+			OpenProgramTask task = new OpenProgramTask(url, this);
-			if (c.getResponseCode() == GhidraURLConnection.GHIDRA_UNAUTHORIZED) {
+			new TaskLauncher(task, tool.getToolFrame());
-				return null; // assume user already notified
+			OpenProgramRequest openProgramReq = task.getOpenProgram();
+			if (openProgramReq != null) {
+				p = openProgramReq.getProgram();
+				showProgram(p, url, openState);
+				openProgramReq.release();
 			}
-			if (!(obj instanceof GhidraURLWrappedContent)) {
-				messageBadProgramURL(ghidraURL);
-				return null;
-			}
-			wrappedContent = (GhidraURLWrappedContent) obj;
-			content = wrappedContent.getContent(this);
-			if (!(content instanceof DomainFile)) {
-				messageBadProgramURL(ghidraURL);
-				return null;
-			}
-			DomainFile df = (DomainFile) content;
-			if (!ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(df.getContentType())) {
-				messageBadProgramURL(ghidraURL);
-				return null;
-			}
-
-			OpenProgramTask task = new OpenProgramTask(df, true, this);
-			TaskLauncher.launch(task);
-
-			openProgram = task.getOpenProgram();
-			if (openProgram == null) {
-				return null;
-			}
-
-			programMgr.addProgram(openProgram, GhidraURL.getNormalizedURL(ghidraURL), openState);
-			contextChanged();
-			openProgram.release(this);
-			if (openState == ProgramManager.OPEN_CURRENT) {
-				gotoProgramRef(openProgram, ghidraURL.getRef());
-				programMgr.saveLocation();
-			}
-			return openProgram;
-		}
-		catch (NotFoundException e) {
-			messageBadProgramURL(ghidraURL);
-		}
-		catch (MalformedURLException e) {
-			Msg.showError(this, null, "Invalid Ghidra URL",
-				"Improperly formed Ghidra URL: " + ghidraURL);
-		}
-		catch (IOException e) {
-			Msg.showError(this, null, "Program Open Failed",
-				"Failed to open Ghidra URL: " + e.getMessage());
 		}
 		finally {
-			if (content != null) {
+			if (p != null && openState == ProgramManager.OPEN_CURRENT) {
-				wrappedContent.release(content, this);
+				gotoProgramRef(p, ghidraURL.getRef());
+				programMgr.saveLocation();
 			}
 		}
-		return null;
+		return p;
 	}
 
 	private boolean gotoProgramRef(Program program, String ref) {
@@ -296,9 +264,7 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 		}
 
 		Program program = Swing.runNow(() -> {
-			Program p = doOpenProgram(domainFile, version, state);
+			return doOpenProgram(domainFile, version, state);
-			contextChanged();
-			return p;
 		});
 
 		if (program != null) {
@@ -460,13 +426,39 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 
 	@Override
 	public void openProgram(final Program program, final int state) {
+		showProgram(program, program.getDomainFile(), state);
+	}
+
+	private void showProgram(Program p, URL ghidraUrl, final int state) {
+		if (p == null || p.isClosed()) {
+			throw new AssertException("Opened program required");
+		}
 		if (locked) {
 			throw new IllegalStateException(
 				"Progam manager is locked and cannot accept a new program");
 		}
 
 		Runnable r = () -> {
-			programMgr.addProgram(program, null, state);
+			programMgr.addProgram(p, ghidraUrl, state);
+			if (state == ProgramManager.OPEN_CURRENT) {
+				programMgr.saveLocation();
+			}
+			contextChanged();
+		};
+		Swing.runNow(r);
+	}
+
+	private void showProgram(Program p, DomainFile domainFile, final int state) {
+		if (p == null || p.isClosed()) {
+			throw new AssertException("Opened program required");
+		}
+		if (locked) {
+			throw new IllegalStateException(
+				"Progam manager is locked and cannot accept a new program");
+		}
+
+		Runnable r = () -> {
+			programMgr.addProgram(p, domainFile, state);
 			if (state == ProgramManager.OPEN_CURRENT) {
 				programMgr.saveLocation();
 			}
@@ -625,11 +617,9 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 					doOpenProgram(domainFile, version, OPEN_CURRENT);
 				}
 			};
-			DomainFileFilter filter = f -> {
+			openDialog = new OpenVersionedFileDialog(tool, "Open Program", f -> {
-				Class<?> c = f.getDomainObjectClass();
+				return Program.class.isAssignableFrom(f.getDomainObjectClass());
-				return Program.class.isAssignableFrom(c);
+			});
-			};
-			openDialog = new OpenVersionedFileDialog(tool, "Open Program", filter);
 			openDialog.setHelpLocation(new HelpLocation(HelpTopics.PROGRAM, "Open_File_Dialog"));
 			openDialog.addOkActionListener(listener);
 		}
@@ -638,9 +628,12 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 	}
 
 	public void openPrograms(List<DomainFile> filesToOpen) {
+		Program showIfNeeded = null;
 		OpenProgramTask openTask = null;
 		for (DomainFile domainFile : filesToOpen) {
-			if (programMgr.getOpenProgram(domainFile, -1) != null) {
+			Program p = programMgr.getOpenProgram(domainFile, -1);
+			if (p != null) {
+				showIfNeeded = p;
 				continue;
 			}
 			if (openTask == null) {
@@ -652,32 +645,37 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 		}
 		if (openTask != null) {
 			new TaskLauncher(openTask, tool.getToolFrame());
-			List<Program> openPrograms = openTask.getOpenPrograms();
+			List<OpenProgramRequest> openProgramReqs = openTask.getOpenPrograms();
-
+			boolean isFirst = true;
-			for (Program program : openPrograms) {
+			for (OpenProgramRequest programReq : openProgramReqs) {
-				openProgram(program, OPEN_VISIBLE);
+				showProgram(programReq.getProgram(), programReq.getDomainFile(),
-				program.release(this);
+					isFirst ? OPEN_CURRENT : OPEN_VISIBLE);
+				programReq.release();
+				isFirst = false;
+				showIfNeeded = null;
 			}
-			if (!openPrograms.isEmpty()) {
-				openProgram(openPrograms.get(0), OPEN_CURRENT);
 		}
+		if (showIfNeeded != null) {
+			showProgram(showIfNeeded, showIfNeeded.getDomainFile(), OPEN_CURRENT);
 		}
 	}
 
 	protected Program doOpenProgram(DomainFile domainFile, int version, int openState) {
-		Program openProgram = programMgr.getOpenProgram(domainFile, version);
+		Program p = programMgr.getOpenProgram(domainFile, version);
-		if (openProgram != null) {
+		if (p != null) {
-			openProgram(openProgram, openState);
+			openProgram(p, openState);
-			return openProgram;
 		}
+		else {
 			OpenProgramTask task = new OpenProgramTask(domainFile, version, this);
 			new TaskLauncher(task, tool.getToolFrame());
-		openProgram = task.getOpenProgram();
+			OpenProgramRequest programReq = task.getOpenProgram();
-		if (openProgram != null) {
+			if (programReq != null) {
-			openProgram(openProgram, openState);
+				p = programReq.getProgram();
-			openProgram.release(this);
+				showProgram(p, programReq.getDomainFile(), openState);
+				programReq.release();
 			}
-		return openProgram;
+		}
+		return p;
 	}
 
 	@Override
@@ -705,18 +703,20 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 	 */
 	@Override
 	public void writeDataState(SaveState saveState) {
-		// Only remember programs from non-transient projects
+
-		ArrayList<Program> programs = new ArrayList<>();
+		ArrayList<ProgramInfo> programInfos = new ArrayList<>();
 		for (Program p : programMgr.getAllPrograms()) {
-			ProjectLocator projectLocator = p.getDomainFile().getProjectLocator();
+			ProgramInfo info = programMgr.getInfo(p);
-			if (projectLocator != null && !projectLocator.isTransient()) {
+			if (info != null) {
-				programs.add(p);
+				programInfos.add(info);
 			}
 		}
-		saveState.putInt("NUM_PROGRAMS", programs.size());
+
+		saveState.putInt("NUM_PROGRAMS", programInfos.size());
+
 		int i = 0;
-		for (Program p : programs) {
+		for (ProgramInfo programInfo : programInfos) {
-			writeProgramInfo(p, saveState, i++);
+			writeProgramInfo(programInfo, saveState, i++);
 		}
 		Program p = programMgr.getCurrentProgram();
 		if (p != null) {
@@ -768,13 +768,21 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 		}
 	}
 
-	private void writeProgramInfo(Program program, SaveState saveState, int index) {
+	private void writeProgramInfo(ProgramInfo programInfo, SaveState saveState, int index) {
 		if (locked) {
 			return; // do not save state when locked.
 		}
+
+		if (programInfo.ghidraURL != null) {
+			saveState.putString("URL_" + index, programInfo.ghidraURL.toString());
+			return;
+		}
+
 		String projectLocation = null;
 		String projectName = null;
 		String path = null;
+
+		Program program = programInfo.program;
 		DomainFile df = program.getDomainFile();
 		ProjectLocator projectLocator = df.getProjectLocator();
 		if (projectLocator != null && !projectLocator.isTransient()) {
@@ -797,28 +805,30 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 	 * Read in my data state.
 	 */
 	private void loadPrograms(SaveState saveState) {
+
 		int n = saveState.getInt("NUM_PROGRAMS", 0);
 		if (n == 0) {
 			return;
 		}
-		OpenProgramTask openTask = null;
+		OpenProgramTask openTask = new OpenProgramTask(this);
 
 		for (int index = 0; index < n; index++) {
+
+			URL url = getGhidraURL(saveState, index);
+			if (url != null) {
+				openTask.addProgramToOpen(url);
+				continue;
+			}
+
 			DomainFile domainFile = getDomainFile(saveState, index);
 			if (domainFile == null) {
 				continue;
 			}
 			int version = getVersion(saveState, index);
-
-			if (openTask == null) {
-				openTask = new OpenProgramTask(domainFile, version, this);
-			}
-			else {
 			openTask.addProgramToOpen(domainFile, version);
 		}
-		}
 
-		if (openTask == null) {
+		if (!openTask.hasOpenProgramRequests()) {
 			return;
 		}
 
@@ -835,10 +845,29 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 				"Can't open program", e);
 		}
 
-		List<Program> openPrograms = openTask.getOpenPrograms();
+		List<OpenProgramRequest> openProgramReqs = openTask.getOpenPrograms();
-		for (Program program : openPrograms) {
+		for (OpenProgramRequest programReq : openProgramReqs) {
-			openProgram(program, OPEN_VISIBLE);
+			DomainFile df = programReq.getDomainFile();
-			program.release(this);
+			if (df != null) {
+				showProgram(programReq.getProgram(), df, OPEN_VISIBLE);
+			}
+			else {
+				showProgram(programReq.getProgram(), programReq.getGhidraURL(), OPEN_VISIBLE);
+			}
+			programReq.release();
+		}
+	}
+
+	private URL getGhidraURL(SaveState saveState, int index) {
+		String url = saveState.getString("URL_" + index, null);
+		if (url == null) {
+			return null;
+		}
+		try {
+			return new URL(url);
+		}
+		catch (MalformedURLException e) {
+			return null;
 		}
 	}
 
@@ -853,21 +882,8 @@ public class ProgramManagerPlugin extends Plugin implements ProgramManager {
 
 		ProjectData projectData = tool.getProject().getProjectData(projectLocator);
 		if (projectData == null) {
-			// Viewed project not available
-			try {
-				projectData = new ProjectFileManager(projectLocator, false, false);
-			}
-			catch (NotOwnerException e) {
-				Msg.showError(this, tool.getToolFrame(), "Program Open Failed",
-					"Not project owner: " + projectLocator + "(" + pathname + ")");
 			return null;
 		}
-			catch (IOException e) {
-				Msg.showError(this, tool.getToolFrame(), "Program Open Failed",
-					"Project error: " + e.getMessage());
-				return null;
-			}
-		}
 
 		DomainFile df = projectData.getFile(pathname);
 		if (df == null) {

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/ProgramSaveManager.java

@@ -45,9 +45,17 @@ class ProgramSaveManager {
 	ProgramSaveManager(PluginTool tool, ProgramManager programMgr) {
 		this.tool = tool;
 		this.programMgr = programMgr;
-		domainFileFilter = f -> {
+		domainFileFilter = new DomainFileFilter() {
-			Class<?> c = f.getDomainObjectClass();
+
-			return Program.class.isAssignableFrom(c);
+			@Override
+			public boolean accept(DomainFile df) {
+				return Program.class.isAssignableFrom(df.getDomainObjectClass());
+			}
+
+			@Override
+			public boolean followLinkedFolders() {
+				return false; // can't save to linked-folder (read-only)
+			}
 		};
 	}
 
@@ -244,7 +252,8 @@ class ProgramSaveManager {
 			return;
 		}
 		if (existingFile != null) {
-			String msg = "Program " + name + " already exists.\n" + "Do you want to overwrite it?";
+			String msg = existingFile.getContentType() + " file " + name + " already exists.\n" +
+				"Do you want to overwrite it?";
 			if (OptionDialog.showOptionDialog(tool.getToolFrame(), "Duplicate Name", msg,
 				"Overwrite", OptionDialog.QUESTION_MESSAGE) == OptionDialog.CANCEL_OPTION) {
 				return;

Ghidra/Features/Base/src/main/java/ghidra/app/util/headless/HeadlessAnalyzer.java

@@ -312,7 +312,7 @@ public class HeadlessAnalyzer {
 			Object obj = c.getContent();
 			if (!(obj instanceof GhidraURLWrappedContent)) {
 				throw new IOException(
-					"Connect to repository folder failed. Response code: " + c.getResponseCode());
+					"Connect to repository folder failed. Response code: " + c.getStatusCode());
 			}
 			GhidraURLWrappedContent wrappedContent = (GhidraURLWrappedContent) obj;
 			Object content = null;
@@ -336,7 +336,7 @@ public class HeadlessAnalyzer {
 					processWithImport(folder.getPathname(), filesToImport);
 				}
 			}
-			catch (NotFoundException e) {
+			catch (FileNotFoundException e) {
 				throw new IOException("Connect to repository folder failed");
 			}
 			finally {
@@ -369,7 +369,8 @@ public class HeadlessAnalyzer {
 	 * @param rootFolderPath root folder for imports
 	 * @param filesToImport directories and files to be imported (null or empty is acceptable if
 	 *        				we are in -process mode)
-	 * @throws IOException if there was an IO-related problem
+	 * @throws IOException if there was an IO-related problem.  If caused by a failure to obtain a 
+	 * write-lock on the project the exception cause will a {@code LockException}.
 	 */
 	public void processLocal(String projectLocation, String projectName, String rootFolderPath,
 			List<File> filesToImport) throws IOException {
@@ -1107,6 +1108,8 @@ public class HeadlessAnalyzer {
 			return;
 		}
 
+		// Do not follow folder-links or consider program links.  Using content type
+		// to filter is best way to control this.
 		if (!ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(domFile.getContentType())) {
 			return; // skip non-Program files
 		}
@@ -1275,6 +1278,8 @@ public class HeadlessAnalyzer {
 
 		for (DomainFile domFile : parentFolder.getFiles()) {
 			if (filenamePattern == null || filenamePattern.matcher(domFile.getName()).matches()) {
+				// Do not follow folder-links or consider program links.  Using content type
+				// to filter is best way to control this.
 				if (ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(domFile.getContentType())) {
 					filesProcessed = true;
 					processFileNoImport(domFile);
@@ -1308,6 +1313,8 @@ public class HeadlessAnalyzer {
 		boolean filesProcessed = false;
 
 		DomainFile domFile = parentFolder.getFile(filename);
+		// Do not follow folder-links or consider program links.  Using content type
+		// to filter is best way to control this.
 		if (domFile != null &&
 			ProgramContentHandler.PROGRAM_CONTENT_TYPE.equals(domFile.getContentType())) {
 			filesProcessed = true;

Ghidra/Features/Base/src/main/java/ghidra/app/util/task/OpenProgramTask.java

@@ -16,8 +16,9 @@
 package ghidra.app.util.task;
 
 import java.io.IOException;
-import java.util.ArrayList;
+import java.net.MalformedURLException;
-import java.util.List;
+import java.net.URL;
+import java.util.*;
 
 import docking.widgets.OptionDialog;
 import ghidra.app.util.dialog.CheckoutDialog;
@@ -25,8 +26,11 @@ import ghidra.framework.client.ClientUtil;
 import ghidra.framework.client.RepositoryAdapter;
 import ghidra.framework.main.AppInfo;
 import ghidra.framework.model.DomainFile;
+import ghidra.framework.protocol.ghidra.*;
+import ghidra.framework.protocol.ghidra.GhidraURLConnection.StatusCode;
 import ghidra.framework.remote.User;
 import ghidra.framework.store.ExclusiveCheckoutException;
+import ghidra.program.database.ProgramLinkContentHandler;
 import ghidra.program.model.lang.LanguageNotFoundException;
 import ghidra.program.model.listing.Program;
 import ghidra.util.*;
@@ -37,8 +41,8 @@ import ghidra.util.task.TaskMonitor;
 
 public class OpenProgramTask extends Task {
 
-	private final List<DomainFileInfo> domainFileInfoList = new ArrayList<>();
+	private final List<OpenProgramRequest> openProgramRequests = new ArrayList<>();
-	private List<Program> programList = new ArrayList<>();
+	private List<OpenProgramRequest> openedProgramList = new ArrayList<>();
 
 	private final Object consumer;
 	private boolean silent; // if true operation does not permit interaction
@@ -46,11 +50,16 @@ public class OpenProgramTask extends Task {
 
 	private String openPromptText = "Open";
 
+	public OpenProgramTask(Object consumer) {
+		super("Open Program(s)", true, false, true);
+		this.consumer = consumer;
+	}
+
 	public OpenProgramTask(DomainFile domainFile, int version, boolean forceReadOnly,
 			Object consumer) {
 		super("Open Program(s)", true, false, true);
 		this.consumer = consumer;
-		domainFileInfoList.add(new DomainFileInfo(domainFile, version, forceReadOnly));
+		openProgramRequests.add(new OpenProgramRequest(domainFile, version, forceReadOnly));
 	}
 
 	public OpenProgramTask(DomainFile domainFile, int version, Object consumer) {
@@ -65,17 +74,10 @@ public class OpenProgramTask extends Task {
 		this(domainFile, DomainFile.DEFAULT_VERSION, false, consumer);
 	}
 
-	public OpenProgramTask(List<DomainFile> domainFileList, boolean forceReadOnly,
+	public OpenProgramTask(URL ghidraURL, Object consumer) {
-			Object consumer) {
+		super("Open Program(s)", true, false, true);
-		super("Open Program(s)", true, domainFileList.size() > 1, true);
 		this.consumer = consumer;
-		for (DomainFile domainFile : domainFileList) {
+		openProgramRequests.add(new OpenProgramRequest(ghidraURL));
-			domainFileInfoList.add(new DomainFileInfo(domainFile, -1, forceReadOnly));
-		}
-	}
-
-	public OpenProgramTask(List<DomainFile> domainFileList, Object consumer) {
-		this(domainFileList, false, consumer);
 	}
 
 	public void setOpenPromptText(String text) {
@@ -88,7 +90,16 @@ public class OpenProgramTask extends Task {
 
 	public void addProgramToOpen(DomainFile domainFile, int version, boolean forceReadOnly) {
 		setHasProgress(true);
-		domainFileInfoList.add(new DomainFileInfo(domainFile, version, forceReadOnly));
+		openProgramRequests.add(new OpenProgramRequest(domainFile, version, forceReadOnly));
+	}
+
+	public void addProgramToOpen(URL ghidraURL) {
+		setHasProgress(true);
+		openProgramRequests.add(new OpenProgramRequest(ghidraURL));
+	}
+
+	public boolean hasOpenProgramRequests() {
+		return !openProgramRequests.isEmpty();
 	}
 
 	/**
@@ -110,100 +121,97 @@ public class OpenProgramTask extends Task {
 		this.noCheckout = true;
 	}
 
-	public List<Program> getOpenPrograms() {
+	/**
-		return programList;
+	 * Get all successful open program requests
+	 * @return all successful open program requests
+	 */
+	public List<OpenProgramRequest> getOpenPrograms() {
+		return Collections.unmodifiableList(openedProgramList);
 	}
 
-	public Program getOpenProgram() {
+	/**
-		if (programList.isEmpty()) {
+	 * Get the first successful open program request
+	 * @return first successful open program request or null if none
+	 */
+	public OpenProgramRequest getOpenProgram() {
+		if (openedProgramList.isEmpty()) {
 			return null;
 		}
-		return programList.get(0);
+		return openedProgramList.get(0);
 	}
 
 	@Override
 	public void run(TaskMonitor monitor) {
 
-		taskMonitor.initialize(domainFileInfoList.size());
+		taskMonitor.initialize(openProgramRequests.size());
 
-		for (DomainFileInfo domainFileInfo : domainFileInfoList) {
+		for (OpenProgramRequest domainFileInfo : openProgramRequests) {
 			if (taskMonitor.isCancelled()) {
 				return;
 			}
-			openDomainFile(domainFileInfo);
+			domainFileInfo.open();
-
 			taskMonitor.incrementProgress(1);
 		}
 	}
 
-	private void openDomainFile(DomainFileInfo domainFileInfo) {
+	private Object openReadOnlyFile(DomainFile domainFile, URL url, int version) {
-		int version = domainFileInfo.getVersion();
-		DomainFile domainFile = domainFileInfo.getDomainFile();
-		if (version != DomainFile.DEFAULT_VERSION) {
-			openVersionedFile(domainFile, version);
-		}
-		else if (domainFileInfo.isReadOnly()) {
-			openReadOnlyFile(domainFile, version);
-		}
-		else {
-			openUnversionedFile(domainFile);
-		}
-	}
-
-	private void openReadOnlyFile(DomainFile domainFile, int version) {
 		taskMonitor.setMessage("Opening " + domainFile.getName());
-		openReadOnly(domainFile, version);
+		return openReadOnly(domainFile, url, version);
 	}
 
-	private void openVersionedFile(DomainFile domainFile, int version) {
+	private Object openVersionedFile(DomainFile domainFile, URL url, int version) {
 		taskMonitor.setMessage("Getting Version " + version + " for " + domainFile.getName());
-		openReadOnly(domainFile, version);
+		return openReadOnly(domainFile, url, version);
 	}
 
-	private void openReadOnly(DomainFile domainFile, int version) {
+	private Object openReadOnly(DomainFile domainFile, URL url, int version) {
-		String contentType = null;
+		String contentType = domainFile.getContentType();
+		String path = url != null ? url.toString() : domainFile.getPathname();
+		Object obj = null;
 		try {
-			contentType = domainFile.getContentType();
-			Program program =
-				(Program) domainFile.getReadOnlyDomainObject(consumer, version, taskMonitor);
 
-			if (program == null) {
+			obj = domainFile.getReadOnlyDomainObject(consumer, version, taskMonitor);
-				String errorMessage = "Can't open program - \"" + domainFile.getPathname() + "\"";
+
+			if (obj == null) {
+				String errorMessage = "Can't open " + contentType + " - \"" + path + "\"";
 				if (version != DomainFile.DEFAULT_VERSION) {
 					errorMessage += " version " + version;
 				}
 
-				Msg.showError(this, null, "DomainFile Not Found", errorMessage);
+				Msg.showError(this, null, "File Not Found", errorMessage);
-			}
-			else {
-				programList.add(program);
 			}
+			
 		}
 		catch (CancelledException e) {
 			// we don't care, the task has been cancelled
 		}
 		catch (IOException e) {
-			if (domainFile.isInWritableProject()) {
+			if (url == null && domainFile.isInWritableProject()) {
 				ClientUtil.handleException(AppInfo.getActiveProject().getRepository(), e,
-					"Get Versioned Object", null);
+					"Get " + contentType, null);
+			}
+			else if (version != DomainFile.DEFAULT_VERSION) {
+				Msg.showError(this, null, "Error Getting Versioned Program",
+					"Could not get version " + version + " for " + path, e);
 			}
 			else {
-				Msg.showError(this, null, "Error Getting Versioned Object",
+				Msg.showError(this, null, "Error Getting Program",
-					"Could not get version " + version + " for " + domainFile.getName(), e);
+					"Open program failed for " + path, e);
 			}
 		}
 		catch (VersionException e) {
 			VersionExceptionHandler.showVersionError(null, domainFile.getName(), contentType,
 				"Open", e);
 		}
+		return obj;
 	}
 
-	private void openUnversionedFile(DomainFile domainFile) {
+	private Program openUnversionedFile(DomainFile domainFile) {
 		String filename = domainFile.getName();
 		taskMonitor.setMessage("Opening " + filename);
 		performOptionalCheckout(domainFile);
 		try {
-			openFileMaybeUgrade(domainFile);
+			return openFileMaybeUgrade(domainFile);
 		}
 		catch (VersionException e) {
 			String contentType = domainFile.getContentType();
@@ -226,9 +234,10 @@ public class OpenProgramTask extends Task {
 					"Getting domain object failed.\n" + e.getMessage(), e);
 			}
 		}
+		return null;
 	}
 
-	private void openFileMaybeUgrade(DomainFile domainFile)
+	private Program openFileMaybeUgrade(DomainFile domainFile)
 			throws IOException, CancelledException, VersionException {
 
 		boolean recoverFile = false;
@@ -236,24 +245,18 @@ public class OpenProgramTask extends Task {
 			recoverFile = askRecoverFile(domainFile.getName());
 		}
 
+		Program program = null;
 		try {
-			Program program =
+			program =
 				(Program) domainFile.getDomainObject(consumer, false, recoverFile, taskMonitor);
-
-			if (program != null) {
-				programList.add(program);
-			}
-
 		}
 		catch (VersionException e) {
 			if (VersionExceptionHandler.isUpgradeOK(null, domainFile, openPromptText, e)) {
-				Program program =
+				program =
 					(Program) domainFile.getDomainObject(consumer, true, recoverFile, taskMonitor);
-				if (program != null) {
-					programList.add(program);
-				}
 			}
 		}
+		return program;
 	}
 
 	private boolean askRecoverFile(final String filename) {
@@ -294,32 +297,158 @@ public class OpenProgramTask extends Task {
 		}
 	}
 
-	static class DomainFileInfo {
+	public class OpenProgramRequest {
-		private final DomainFile domainFile;
-		private final int version;
-		private boolean forceReadOnly;
 
-		public DomainFileInfo(DomainFile domainFile, int version, boolean forceReadOnly) {
+		// ghidraURL and domainFile use are mutually exclusive
+		private final URL ghidraURL;
+		private final DomainFile domainFile;
+
+		private URL linkURL; // link URL read from domainFile
+
+		private final int version;
+		private final boolean forceReadOnly;
+		private Program program;
+
+		public OpenProgramRequest(URL ghidraURL) {
+			if (!GhidraURL.PROTOCOL.equals(ghidraURL.getProtocol())) {
+				throw new IllegalArgumentException(
+					"unsupported protocol: " + ghidraURL.getProtocol());
+			}
+			this.ghidraURL = ghidraURL;
+			this.domainFile = null;
+			this.version = -1;
+			this.forceReadOnly = true;
+		}
+
+		public OpenProgramRequest(DomainFile domainFile, int version, boolean forceReadOnly) {
 			this.domainFile = domainFile;
+			this.ghidraURL = null;
 			this.version =
 				(domainFile.isReadOnly() && domainFile.isVersioned()) ? domainFile.getVersion()
 						: version;
 			this.forceReadOnly = forceReadOnly;
 		}
 
-		public boolean isReadOnly() {
+		/**
-			return forceReadOnly || domainFile.isReadOnly() ||
+		 * Get the {@link DomainFile} which corresponds to program open request.  This will be
-				version != DomainFile.DEFAULT_VERSION;
+		 * null for all URL-based open requests.
-		}
+		 * @return {@link DomainFile} which corresponds to program open request or null.
-
+		 */
 		public DomainFile getDomainFile() {
 			return domainFile;
 		}
 
-		public int getVersion() {
+		/**
-			return version;
+		 * Get the {@link URL} which corresponds to program open request.  This will be
+		 * null for all non-URL-based open requests.  URL will be a {@link GhidraURL}.
+		 * @return {@link URL} which corresponds to program open request or null.
+		 */
+		public URL getGhidraURL() {
+			return ghidraURL;
 		}
 
+		/**
+		 * Get the {@link URL} which corresponds to the link domainFile used to open a program.
+		 * @return {@link URL} which corresponds to the link domainFile used to open a program.
+		 */
+		public URL getLinkURL() {
+			return linkURL;
+		}
+
+		/**
+		 * Get the open Program instance which corresponds to this open request.
+		 * @return program instance or null if never opened.
+		 */
+		public Program getProgram() {
+			return program;
+		}
+
+		/**
+		 * Release opened program.  This must be done once, and only once, on a successful 
+		 * open request.  If handing ownership off to another consumer, they should be added
+		 * as a program consumer prior to invoking this method.  Releasing the last consumer
+		 * will close the program instance.
+		 */
+		public void release() {
+			if (program != null) {
+				program.release(consumer);
+			}
+		}
+
+		private Program openProgram(DomainFile df, URL url) {
+			if (version != DomainFile.DEFAULT_VERSION) {
+				return (Program) openVersionedFile(df, url, version);
+			}
+			if (forceReadOnly) {
+				return (Program) openReadOnlyFile(df, url, version);
+			}
+			return openUnversionedFile(df);
+		}
+
+		void open() {
+			DomainFile df = domainFile;
+			URL url = ghidraURL;
+			GhidraURLWrappedContent wrappedContent = null;
+			Object content = null;
+			try {
+				if (df == null && url != null) {
+					GhidraURLConnection c = (GhidraURLConnection) url.openConnection();
+					Object obj = c.getContent(); // read-only access
+					if (c.getStatusCode() == StatusCode.UNAUTHORIZED) {
+						return; // assume user already notified
+					}
+					if (!(obj instanceof GhidraURLWrappedContent)) {
+						messageBadProgramURL(url);
+						return;
+					}
+					wrappedContent = (GhidraURLWrappedContent) obj;
+					content = wrappedContent.getContent(this);
+					if (!(content instanceof DomainFile)) {
+						messageBadProgramURL(url);
+						return;
+					}
+					df = (DomainFile) content;
+
+					if (ProgramLinkContentHandler.PROGRAM_LINK_CONTENT_TYPE
+							.equals(df.getContentType())) {
+						Msg.showError(this, null, "Program Multi-Link Error",
+							"Multi-link Program access not supported: " + url);
+						return;
+					}
+				}
+
+				if (!Program.class.isAssignableFrom(df.getDomainObjectClass())) {
+					Msg.showError(this, null, "Error Opening Program",
+						"File does not correspond to a Ghidra Program: " + df.getPathname());
+					return;
+				}
+
+				program = openProgram(df, url);
+
+			}
+			catch (MalformedURLException e) {
+				Msg.showError(this, null, "Invalid Ghidra URL",
+					"Improperly formed Ghidra URL: " + url);
+			}
+			catch (IOException e) {
+				Msg.showError(this, null, "Program Open Failed",
+					"Failed to open Ghidra URL: " + e.getMessage());
+			}
+			finally {
+				if (content != null) {
+					wrappedContent.release(content, this);
+				}
+			}
+
+			if (program != null) {
+				openedProgramList.add(this);
+			}
+		}
+
+		private void messageBadProgramURL(URL url) {
+			Msg.error("Invalid Ghidra URL",
+				"Ghidra URL does not reference a Ghidra Program: " + url);
+		}
 	}
 
 }

Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/Annotation.java

@@ -33,6 +33,7 @@ public class Annotation {
 	private static final Pattern QUOTATION_PATTERN =
 		Pattern.compile("(?<!\\\\)[\"](.*?)(?<!\\\\)[\"]");
 
+	private static List<AnnotatedStringHandler> ANNOTATED_STRING_HANDLERS;
 	private static Map<String, AnnotatedStringHandler> ANNOTATED_STRING_MAP;
 
 	private String annotationText;
@@ -40,6 +41,13 @@ public class Annotation {
 	private AnnotatedStringHandler annotatedStringHandler;
 	private AttributedString displayString;
 
+	public static List<AnnotatedStringHandler> getAnnotatedStringHandlers() {
+		if (ANNOTATED_STRING_HANDLERS == null) {
+			ANNOTATED_STRING_HANDLERS = getSupportedAnnotationHandlers();
+		}
+		return ANNOTATED_STRING_HANDLERS;
+	}
+
 	private static Map<String, AnnotatedStringHandler> getAnnotatedStringHandlerMap() {
 		if (ANNOTATED_STRING_MAP == null) { // lazy init due to our use of ClassSearcher
 			ANNOTATED_STRING_MAP = createAnnotatedStringHandlerMap();
@@ -47,24 +55,28 @@ public class Annotation {
 		return ANNOTATED_STRING_MAP;
 	}
 
-	// locates AnnotatedStringHandler implementations to handle annotations
 	private static Map<String, AnnotatedStringHandler> createAnnotatedStringHandlerMap() {
 		Map<String, AnnotatedStringHandler> map = new HashMap<>();
-
+		for (AnnotatedStringHandler instance : getAnnotatedStringHandlers()) {
-		// find all instances of AnnotatedString
-		List<AnnotatedStringHandler> instances =
-			ClassSearcher.getInstances(AnnotatedStringHandler.class);
-
-		for (AnnotatedStringHandler instance : instances) {
 			String[] supportedAnnotations = instance.getSupportedAnnotations();
 			for (String supportedAnnotation : supportedAnnotations) {
 				map.put(supportedAnnotation, instance);
 			}
 		}
-
 		return Collections.unmodifiableMap(map);
 	}
 
+	// locates AnnotatedStringHandler implementations to handle annotations
+	private static List<AnnotatedStringHandler> getSupportedAnnotationHandlers() {
+		List<AnnotatedStringHandler> list = new ArrayList<>();
+		for (AnnotatedStringHandler h : ClassSearcher.getInstances(AnnotatedStringHandler.class)) {
+			if (h.getSupportedAnnotations().length != 0) {
+				list.add(h);
+			}
+		}
+		return Collections.unmodifiableList(list);
+	}
+
 	/**
 	 * Constructor
 	 * <b>Note</b>: This constructor assumes that the string starts with "{<pre>@</pre>" and ends with '}'
@@ -184,14 +196,6 @@ public class Annotation {
 		return annotationText;
 	}
 
-	public static AnnotatedStringHandler[] getAnnotatedStringHandlers() {
-		Set<AnnotatedStringHandler> annotations =
-			new HashSet<>(getAnnotatedStringHandlerMap().values());
-		AnnotatedStringHandler[] retVal = new AnnotatedStringHandler[annotations.size()];
-		annotations.toArray(retVal);
-		return retVal;
-	}
-
 	/*package*/ static Set<String> getAnnotationNames() {
 		return Collections.unmodifiableSet(getAnnotatedStringHandlerMap().keySet());
 	}

Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/GhidraLocalURLAnnotatedStringHandler.java

@@ -0,0 +1,34 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.app.util.viewer.field;
+
+/**
+ * This implementation expands {@link URLAnnotatedStringHandler} providing an example form
+ * of a local project Ghidra URL.
+ */
+public class GhidraLocalURLAnnotatedStringHandler extends URLAnnotatedStringHandler {
+
+	@Override
+	public String getDisplayString() {
+		return "Ghidra-URL(local)";
+	}
+
+	@Override
+	public String getPrototypeString() {
+		return "{@url \"ghidra:/dirpath/myproject?/folder/program.exe#symbol\" \"display string\"}";
+	}
+
+}

Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/GhidraServerURLAnnotatedStringHandler.java

@@ -0,0 +1,34 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.app.util.viewer.field;
+
+/**
+ * This implementation expands {@link URLAnnotatedStringHandler} providing an example form
+ * of a Ghidra Server URL.
+ */
+public class GhidraServerURLAnnotatedStringHandler extends URLAnnotatedStringHandler {
+
+	@Override
+	public String getDisplayString() {
+		return "Ghidra-URL(remote)";
+	}
+
+	@Override
+	public String getPrototypeString() {
+		return "{@url \"ghidra://myserver/myrepo/folder/program.exe#symbol\" \"display string\"}";
+	}
+
+}

Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/URLAnnotatedStringHandler.java

@@ -36,8 +36,10 @@ import ghidra.util.Msg;
  * displayed.
  */
 public class URLAnnotatedStringHandler implements AnnotatedStringHandler {
+
 	private static final String INVALID_SYMBOL_TEXT =
-		"@url annotation must have a URL string " + "optionally followed by a display string";
+		"@url annotation must have a URL string optionally followed by a display string";
+
 	private static final String[] SUPPORTED_ANNOTATIONS = { "url", "hyperlink", "href", "link" };
 
 	@Override

Ghidra/Features/Base/src/main/java/ghidra/base/project/GhidraProject.java

@@ -233,6 +233,13 @@ public class GhidraProject {
 		return project;
 	}
 
+	/**
+	 * Returns the underlying ProjectData instance.
+	 */
+	public ProjectData getProjectData() {
+		return projectData;
+	}
+
 	/**
 	 * Closes the ghidra project, closing (without saving!) any open programs in
 	 * that project. Also deletes the project if created as a temporary project.

Ghidra/Features/Base/src/main/java/ghidra/framework/main/DataTreeDialog.java

@@ -93,7 +93,10 @@ public class DataTreeDialog extends DialogComponentProvider
 	private Integer treeSelectionMode;
 
 	/**
-	 * Construct a new DataTreeDialog.
+	 * Construct a new DataTreeDialog.  This chooser will show all project files.  
+	 * Following linked-folders will only be allowed if a type of {@link #CHOOSE_FOLDER}
+	 * or {@link #OPEN} is specified.  If different behavior is required a filter should 
+	 * be specified using the other constructor. 
 	 *
 	 * @param parent dialog's parent
 	 * @param title title to use
@@ -101,7 +104,7 @@ public class DataTreeDialog extends DialogComponentProvider
 	 * @throws IllegalArgumentException if invalid type is specified
 	 */
 	public DataTreeDialog(Component parent, String title, int type) {
-		this(parent, title, type, null);
+		this(parent, title, type, getDefaultFilter(type));
 	}
 
 	/**
@@ -119,6 +122,20 @@ public class DataTreeDialog extends DialogComponentProvider
 		initDataTreeDialog(type, filter);
 	}
 
+	private static DomainFileFilter getDefaultFilter(int type) {
+		if (type == CHOOSE_FOLDER || type == OPEN) {
+			// return filter which forces folder selection and allow navigation into linked-folders
+			return new DomainFileFilter() {
+
+				@Override
+				public boolean accept(DomainFile df) {
+					return true; // show all files (legacy behavior)
+				}
+			};
+		}
+		return null;
+	}
+
 	public void setTreeSelectionMode(int mode) {
 		if (treePanel != null) {
 			treePanel.getTreeSelectionModel().setSelectionMode(mode);

Ghidra/Features/Base/src/main/java/ghidra/test/TestEnv.java

@@ -18,6 +18,7 @@ package ghidra.test;
 import java.awt.Dialog;
 import java.awt.Window;
 import java.io.*;
+import java.net.URL;
 import java.util.*;
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
@@ -47,6 +48,7 @@ import ghidra.framework.plugintool.Plugin;
 import ghidra.framework.plugintool.PluginTool;
 import ghidra.framework.plugintool.util.PluginException;
 import ghidra.framework.project.DefaultProjectManager;
+import ghidra.framework.protocol.ghidra.GhidraURL;
 import ghidra.program.database.ProgramDB;
 import ghidra.program.model.data.FileDataTypeManager;
 import ghidra.program.model.lang.*;
@@ -874,10 +876,58 @@ public class TestEnv {
 	 * @param domainFile The domain file used to launch the tool; may be null
 	 * @return the tool that is launched
 	 */
-	public PluginTool launchTool(final String toolName, final DomainFile domainFile) {
+	public PluginTool launchTool(String toolName, DomainFile domainFile) {
 		AtomicReference<PluginTool> ref = new AtomicReference<>();
 
 		AbstractGenericTest.runSwing(() -> {
+			PluginTool newTool = doLaunchTool(toolName);
+			ref.set(newTool);
+			if (newTool != null) {
+				newTool.acceptDomainFiles(new DomainFile[] { domainFile });
+			}
+		});
+
+		PluginTool launchedTool = ref.get();
+		if (launchedTool == null) {
+			throw new NullPointerException("Unable to launch the tool: " + toolName);
+		}
+
+		// this will make sure that our tool is closed during disposal
+		extraTools.add(launchedTool);
+		return launchedTool;
+	}
+
+	/**
+	 * Launches a tool of the given name using the given Ghidra URL.
+	 * <p>
+	 * Note: the tool returned will have auto save disabled by default.
+	 *
+	 * @param toolName the name of the tool to launch
+	 * @param ghidraUrl The Ghidra URL to be opened in tool (see {@link GhidraURL})
+	 * @return the tool that is launched
+	 */
+	public PluginTool launchToolWithURL(String toolName, URL ghidraUrl) {
+		AtomicReference<PluginTool> ref = new AtomicReference<>();
+
+		AbstractGenericTest.runSwing(() -> {
+			PluginTool newTool = doLaunchTool(toolName);
+			ref.set(newTool);
+			if (newTool != null) {
+				newTool.accept(ghidraUrl);
+			}
+		});
+
+		PluginTool launchedTool = ref.get();
+		if (launchedTool == null) {
+			throw new NullPointerException("Unable to launch the tool: " + toolName);
+		}
+
+		// this will make sure that our tool is closed during disposal
+		extraTools.add(launchedTool);
+		return launchedTool;
+	}
+
+	private PluginTool doLaunchTool(String toolName) {
 		boolean wasErrorGUIEnabled = AbstractDockingTest.isUseErrorGUI();
 		AbstractDockingTest.setErrorGUIEnabled(false); // disable the error GUI while launching the tool
 		FrontEndTool frontEndToolInstance = getFrontEndTool();
@@ -889,21 +939,8 @@ public class TestEnv {
 			// couldn't find the tool in the workspace...check the test area
 			newTool = launchDefaultToolByName(toolName);
 		}
-
-			ref.set(newTool);
-
 		AbstractDockingTest.setErrorGUIEnabled(wasErrorGUIEnabled);
-			newTool.acceptDomainFiles(new DomainFile[] { domainFile });
+		return newTool;
-		});
-
-		PluginTool launchedTool = ref.get();
-		if (launchedTool == null) {
-			throw new NullPointerException("Unable to launch the tool: " + toolName);
-		}
-
-		// this will make sure that our tool is closed during disposal
-		extraTools.add(launchedTool);
-		return launchedTool;
 	}
 
 	/**

Ghidra/Features/Base/src/test.slow/java/ghidra/app/util/viewer/field/AnnotationTest.java

@@ -19,6 +19,8 @@ import static org.hamcrest.CoreMatchers.*;
 import static org.junit.Assert.*;
 
 import java.awt.*;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -37,6 +39,8 @@ import ghidra.framework.model.*;
 import ghidra.framework.plugintool.ServiceProvider;
 import ghidra.framework.plugintool.TestDummyServiceProvider;
 import ghidra.framework.project.ProjectDataService;
+import ghidra.framework.protocol.ghidra.GhidraURLConnection;
+import ghidra.framework.store.FileSystem;
 import ghidra.program.database.ProgramBuilder;
 import ghidra.program.database.ProgramDB;
 import ghidra.program.model.address.Address;
@@ -620,6 +624,60 @@ public class AnnotationTest extends AbstractGhidraHeadedIntegrationTest {
 		assertTrue(spyNavigatable.navigatedTo(otherProgramPath, address));
 	}
 
+	@Test
+	public void testGhidraLocalUrlAnnotation_Program_WithAddress() {
+
+		SpyNavigatable spyNavigatable = new SpyNavigatable();
+		SpyServiceProvider spyServiceProvider = new SpyServiceProvider();
+
+		String addresstring = "1001000";
+
+		String pathname = "/a/b/prog";
+		String url = "ghidra:/folder/project?" + pathname + "#" + addresstring;
+		String annotationText = "{@url \"" + url + "\"}";
+		String rawComment = "My comment - " + annotationText;
+		AttributedString prototype = prototype();
+		FieldElement element =
+			CommentUtils.parseTextForAnnotations(rawComment, program, prototype, 0);
+
+		String displayString = element.getText();
+		assertEquals("My comment - " + url, displayString);
+
+		AnnotatedTextFieldElement annotatedElement = getAnnotatedTextFieldElement(element);
+		click(spyNavigatable, spyServiceProvider, annotatedElement);
+
+		assertTrue(spyServiceProvider.programOpened(pathname));
+
+		// Navigation performed by ProgramManager not tested due to use of spyServiceProvider
+	}
+
+	@Test
+	public void testGhidraServerUrlAnnotation_Program_WithAddress() {
+
+		SpyNavigatable spyNavigatable = new SpyNavigatable();
+		SpyServiceProvider spyServiceProvider = new SpyServiceProvider();
+
+		String addresstring = "1001000";
+
+		String pathname = "/a/b/prog";
+		String url = "ghidra://server/repo" + pathname + "#" + addresstring;
+		String annotationText = "{@url \"" + url + "\"}";
+		String rawComment = "My comment - " + annotationText;
+		AttributedString prototype = prototype();
+		FieldElement element =
+			CommentUtils.parseTextForAnnotations(rawComment, program, prototype, 0);
+
+		String displayString = element.getText();
+		assertEquals("My comment - " + url, displayString);
+
+		AnnotatedTextFieldElement annotatedElement = getAnnotatedTextFieldElement(element);
+		click(spyNavigatable, spyServiceProvider, annotatedElement);
+
+		assertTrue(spyServiceProvider.programOpened(pathname));
+
+		// Navigation performed by ProgramManager not tested due to use of spyServiceProvider
+	}
+
 	@Test
 	public void testUnknownAnnotation() {
 		String rawComment = "This is a symbol {@syyyybol bob} annotation";
@@ -903,13 +961,7 @@ public class AnnotationTest extends AbstractGhidraHeadedIntegrationTest {
 		private Set<String> openedPrograms = new HashSet<>();
 		private Set<String> closedPrograms = new HashSet<>();
 
-		@Override
+		private Program generateProgram(String pathname, String name) {
-		public Program openProgram(DomainFile domainFile, int version, int state) {
-			String name = domainFile.getName();
-			String pathname = domainFile.getPathname();
-
-			openedPrograms.add(name);
-
 			try {
 				ProgramBuilder builder = new ProgramBuilder();
 				builder.setName(pathname);
@@ -923,6 +975,39 @@ public class AnnotationTest extends AbstractGhidraHeadedIntegrationTest {
 			}
 		}
 
+		@Override
+		public Program openProgram(URL ghidraURL, int state) {
+			try {
+				GhidraURLConnection c = new GhidraURLConnection(ghidraURL);
+				String folderpath = c.getFolderPath();
+				String name = c.getFolderItemName();
+				String pathname = folderpath;
+				if (!pathname.endsWith(FileSystem.SEPARATOR)) {
+					pathname += FileSystem.SEPARATOR;
+				}
+				pathname += name;
+				openedPrograms.add(name);
+
+				Program p = generateProgram(pathname, name);
+
+				// NOTE: URL ref navigation not performed
+
+				return p;
+			}
+			catch (MalformedURLException e) {
+				failWithException("Bad URL", e);
+			}
+			return null;
+		}
+
+		@Override
+		public Program openProgram(DomainFile domainFile, int version, int state) {
+			String name = domainFile.getName();
+			String pathname = domainFile.getPathname();
+			openedPrograms.add(name);
+			return generateProgram(pathname, name);
+		}
+
 		@Override
 		public boolean closeProgram(Program p, boolean ignoreChanges) {
 			String name = FilenameUtils.getName(p.getName());

Ghidra/Features/Base/src/test.slow/java/ghidra/framework/data/ProjectFileManagerTest.java

@@ -121,13 +121,8 @@ public class ProjectFileManagerTest extends AbstractGhidraHeadedIntegrationTest
 		// If there are queued actions, then we have to kick the handling thread and 
 		// let it finish running.
 
-		try {
 		assertTrue(eventManager.flushEvents(DEFAULT_WAIT_TIMEOUT, TimeUnit.MILLISECONDS));
 	}
-		catch (InterruptedException e) {
-			failWithException("Interrupted waiting for filesystem events", e);
-		}
-	}
 
 	private void deleteAll(File file) {
 		if (file.isDirectory()) {

Ghidra/Features/Base/src/test.slow/java/ghidra/framework/main/DataTreeDialogTest.java

@@ -421,15 +421,10 @@ public class DataTreeDialogTest extends AbstractGhidraHeadedIntegrationTest {
 		assertNotNull(dialog);
 	}
 
-	private DomainFileFilter createStartsWithFilter(String startsWith) {
+	private void showFiltered(final String startsWith) {
-		return (df) -> df.getName().startsWith(startsWith);
-	}
-
-	private void showFiltered(String startsWith) {
 		SwingUtilities.invokeLater(() -> {
 			dialog = new DataTreeDialog(frontEndTool.getToolFrame(), "Test Data Tree Dialog",
-				DataTreeDialog.OPEN, createStartsWithFilter(startsWith));
+				DataTreeDialog.OPEN, f -> f.getName().startsWith(startsWith));
-
 			dialog.showComponent();
 		});
 		waitForSwing();

Ghidra/Features/Base/src/test.slow/java/ghidra/framework/project/AddViewToProjectTest.java

@@ -79,10 +79,10 @@ public class AddViewToProjectTest extends AbstractGhidraHeadlessIntegrationTest
 
 		try {
 			URL view = GhidraURL.makeURL(DIRECTORY_NAME, PROJECT_VIEW1);
-			project.addProjectView(view);
+			project.addProjectView(view, true);
 
 			// add another view that will be removed to test the remove
-			project.addProjectView(GhidraURL.makeURL(DIRECTORY_NAME, PROJECT_VIEW2));
+			project.addProjectView(GhidraURL.makeURL(DIRECTORY_NAME, PROJECT_VIEW2), true);
 
 			// validate the view was added to project
 			ProjectLocator[] projViews = project.getProjectViews();

Ghidra/Features/Base/src/test.slow/java/ghidra/framework/project/CreateDomainObjectTest.java

@@ -117,7 +117,7 @@ public class CreateDomainObjectTest extends AbstractGhidraHeadedIntegrationTest
 		project.close();
 		Project project2 = ProjectTestUtils.getProject(testDir, PROJECT_NAME2);
 		try {
-			project2.addProjectView(GhidraURL.makeURL(testDir, PROJECT_NAME1));
+			project2.addProjectView(GhidraURL.makeURL(testDir, PROJECT_NAME1), true);
 		}
 		catch (Exception e) {
 			Assert.fail("View Not found");

Ghidra/Features/Base/src/test/java/ghidra/base/project/FakeRepository.java

@@ -15,15 +15,18 @@
  */
 package ghidra.base.project;
 
+import java.io.File;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
-import generic.test.TestUtils;
+import generic.test.AbstractGTest;
 import ghidra.framework.model.DomainFile;
 import ghidra.framework.remote.User;
+import ghidra.framework.store.local.IndexedV1LocalFileSystem;
 import ghidra.framework.store.local.LocalFileSystem;
 import ghidra.test.TestEnv;
+import utilities.util.FileUtilities;
 
 /**
  * This class represents the idea of a shared Ghidra repository.  This class is meant to be
@@ -54,11 +57,34 @@ public class FakeRepository {
 	private Map<String, User> usersByName = new HashMap<>();
 	private Map<User, FakeSharedProject> projectsByUser = new HashMap<>();
 
+	private File versionedFSDir;
 	private LocalFileSystem versionedFileSystem;
 
-	public FakeRepository() {
+	public FakeRepository() throws IOException {
 		// validation must be enabled if both environments are utilized by a test
 		LocalFileSystem.setValidationRequired();
+
+		versionedFSDir =
+			new File(AbstractGTest.getTestDirectoryPath() + File.separator + "TestRepo.rep");
+		if (versionedFSDir.exists()) {
+			FileUtilities.deleteDir(versionedFSDir);
+		}
+		if (versionedFSDir.exists() || !FileUtilities.createDir(versionedFSDir)) {
+			throw new IOException("Failed to create clean repo dir: " + versionedFSDir);
+		}
+		versionedFileSystem = new MyVersionedFileSystem(versionedFSDir.getPath());
+	}
+
+	private static class MyVersionedFileSystem extends IndexedV1LocalFileSystem {
+		MyVersionedFileSystem(String rootPath) throws IOException {
+			super(rootPath, true, false, true, true);
+		}
+
+		@Override
+		public boolean isShared() {
+			// Enables use of asyncronous event dispatching thread
+			return true;
+		}
 	}
 
 	/**
@@ -109,11 +135,6 @@ public class FakeRepository {
 
 		FakeSharedProject project = new FakeSharedProject(this, user);
 		projectsByUser.put(user, project);
-
-		if (versionedFileSystem == null) {
-			versionedFileSystem = project.getVersionedFileSystem();
-			TestUtils.setInstanceField("isShared", versionedFileSystem, Boolean.TRUE);
-		}
 		return project;
 	}
 
@@ -139,6 +160,8 @@ public class FakeRepository {
 	 */
 	public void dispose() {
 		projectsByUser.values().forEach(p -> disposeProject(p));
+		versionedFileSystem.dispose();
+		FileUtilities.deleteDir(versionedFSDir);
 	}
 
 	private void disposeProject(FakeSharedProject p) {

Ghidra/Features/Base/src/test/java/ghidra/base/project/FakeSharedProject.java

@@ -25,7 +25,7 @@ import java.util.concurrent.TimeUnit;
 
 import org.apache.commons.lang3.StringUtils;
 
-import generic.test.AbstractGenericTest;
+import generic.test.AbstractGTest;
 import generic.test.TestUtils;
 import ghidra.framework.data.*;
 import ghidra.framework.model.*;
@@ -39,6 +39,7 @@ import ghidra.test.TestProgramManager;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.task.TaskMonitor;
 import junit.framework.AssertionFailedError;
+import utilities.util.FileUtilities;
 
 /**
  * This class represents the idea of a shared Ghidra project.  Each project is associated with
@@ -61,21 +62,18 @@ public class FakeSharedProject {
 	public FakeSharedProject(FakeRepository repo, User user) throws IOException {
 
 		this.repo = repo;
-		String projectDirPath = AbstractGenericTest.getTestDirectoryPath();
+		String projectDirPath = AbstractGTest.getTestDirectoryPath();
 		gProject =
 			GhidraProject.createProject(projectDirPath, "TestProject_" + user.getName(), true);
 		gProject.setDeleteOnClose(true);
 
-		LocalFileSystem fs = repo.getSharedFileSystem();
+		// use local shared fake repo versioned file system
-		if (fs != null) {
+		setVersionedFileSystem(repo.getSharedFileSystem());
-			// first project will keeps its versioned file system
-			setVersionedFileSystem(fs);
-		}
 	}
 
 	FakeSharedProject(User user) throws IOException {
 
-		String projectDirPath = AbstractGenericTest.getTestDirectoryPath();
+		String projectDirPath = AbstractGTest.getTestDirectoryPath();
 		gProject =
 			GhidraProject.createProject(projectDirPath, "TestProject_" + user.getName(), true);
 	}
@@ -101,7 +99,7 @@ public class FakeSharedProject {
 	 * @return the project file manager
 	 */
 	public ProjectFileManager getProjectFileManager() {
-		return (ProjectFileManager) gProject.getProject().getProjectData();
+		return (ProjectFileManager) gProject.getProjectData();
 	}
 
 	/**
@@ -369,8 +367,11 @@ public class FakeSharedProject {
 	 * @see FakeRepository#dispose()
 	 */
 	public void dispose() {
+		ProjectLocator projectLocator = getProjectFileManager().getProjectLocator();
 		programManager.disposeOpenPrograms();
 		gProject.close();
+		FileUtilities.deleteDir(projectLocator.getProjectDir());
+		projectLocator.getMarkerFile().delete();
 	}
 
 	@Override
@@ -400,13 +401,8 @@ public class FakeSharedProject {
 			(FileSystemEventManager) TestUtils.getInstanceField("eventManager",
 				versionedFileSystem);
 
-		try {
 		eventManager.flushEvents(DEFAULT_WAIT_TIMEOUT, TimeUnit.MILLISECONDS);
 	}
-		catch (InterruptedException e) {
-			failWithException("Interrupted waiting for filesystem events", e);
-		}
-	}
 
 	private DomainFolder getFolder(String path) throws Exception {
 		Project project = getGhidraProject().getProject();

Ghidra/Features/FunctionID/ghidra_scripts/CollectFailedRelocations.java

@@ -99,6 +99,10 @@ public class CollectFailedRelocations extends GhidraScript {
 			if (monitor.isCancelled()) {
 				return;
 			}
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/FunctionID/ghidra_scripts/CreateMultipleLibraries.java

@@ -258,6 +258,10 @@ public class CreateMultipleLibraries extends GhidraScript {
 		DomainFile[] files = myFolder.getFiles();
 		for (DomainFile domainFile : files) {
 			monitor.checkCanceled();
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/FunctionID/ghidra_scripts/FidStatistics.java

@@ -372,6 +372,10 @@ public class FidStatistics extends GhidraScript {
 		DomainFile[] files = folder.getFiles();
 		for (DomainFile domainFile : files) {
 			monitor.checkCanceled();
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/FunctionID/ghidra_scripts/FindErrors.java

@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +16,9 @@
 //Opens all programs under a chosen domain folder, grabs their error count,
 //then sorts in increasing error order and prints them
 //@category FunctionID
+import java.io.IOException;
+import java.util.*;
+
 import generic.stl.Pair;
 import ghidra.app.script.GhidraScript;
 import ghidra.framework.model.DomainFile;
@@ -27,9 +29,6 @@ import ghidra.util.Msg;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.exception.VersionException;
 
-import java.io.IOException;
-import java.util.*;
-
 public class FindErrors extends GhidraScript {
 
 	@Override
@@ -82,6 +81,10 @@ public class FindErrors extends GhidraScript {
 			if (monitor.isCancelled()) {
 				return;
 			}
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/FunctionID/ghidra_scripts/FindFunctionByHash.java

@@ -100,6 +100,10 @@ public class FindFunctionByHash extends GhidraScript {
 			if (monitor.isCancelled()) {
 				return;
 			}
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/FunctionID/ghidra_scripts/FindNamedFunction.java

@@ -16,6 +16,9 @@
 //Opens all programs under a chosen domain folder, scans them for functions
 //that match a user supplied name, and prints info about the match.
 //@category FunctionID
+import java.io.IOException;
+import java.util.ArrayList;
+
 import ghidra.app.script.GhidraScript;
 import ghidra.feature.fid.service.FidService;
 import ghidra.framework.model.DomainFile;
@@ -26,9 +29,6 @@ import ghidra.util.Msg;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.exception.VersionException;
 
-import java.io.IOException;
-import java.util.ArrayList;
-
 public class FindNamedFunction extends GhidraScript {
 
 	FidService service;
@@ -85,6 +85,10 @@ public class FindNamedFunction extends GhidraScript {
 			if (monitor.isCancelled()) {
 				return;
 			}
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/FunctionID/src/main/java/ghidra/feature/fid/plugin/IngestTask.java

@@ -153,6 +153,10 @@ public class IngestTask extends Task {
 		for (DomainFile domainFile : files) {
 			monitor.checkCanceled();
 			monitor.incrementProgress(1);
+			// Do not follow folder-links or consider program links.  Using content type
+			// to filter is best way to control this.  If program links should be considered
+			// "Program.class.isAssignableFrom(domainFile.getDomainObjectClass())"
+			// should be used.
 			if (domainFile.getContentType().equals(ProgramContentHandler.PROGRAM_CONTENT_TYPE)) {
 				programs.add(domainFile);
 			}

Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/VTSessionDB.java

@@ -21,6 +21,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 
 import db.*;
 import ghidra.app.util.task.OpenProgramTask;
+import ghidra.app.util.task.OpenProgramTask.OpenProgramRequest;
 import ghidra.feature.vt.api.correlator.program.ImpliedMatchProgramCorrelator;
 import ghidra.feature.vt.api.correlator.program.ManualMatchProgramCorrelator;
 import ghidra.feature.vt.api.impl.*;
@@ -309,7 +310,8 @@ public class VTSessionDB extends DomainObjectAdapterDB implements VTSession, VTC
 
 		TaskLauncher.launch(openTask);
 
-		return openTask.getOpenProgram();
+		OpenProgramRequest openProgram = openTask.getOpenProgram();
+		return openProgram != null ? openProgram.getProgram() : null;
 	}
 
 	@Override

Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/impl/VTSessionContentHandler.java

@@ -24,7 +24,8 @@ import db.OpenMode;
 import db.buffers.BufferFile;
 import generic.theme.GIcon;
 import ghidra.feature.vt.api.db.VTSessionDB;
-import ghidra.framework.data.*;
+import ghidra.framework.data.DBContentHandler;
+import ghidra.framework.data.DomainObjectMergeManager;
 import ghidra.framework.model.ChangeSet;
 import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.*;
@@ -34,7 +35,8 @@ import ghidra.util.exception.CancelledException;
 import ghidra.util.exception.VersionException;
 import ghidra.util.task.TaskMonitor;
 
-public class VTSessionContentHandler extends DBContentHandler {
+public class VTSessionContentHandler extends DBContentHandler<VTSessionDB> {
+
 	private static Icon ICON = new GIcon("icon.version.tracking.session.content.type");
 
 	public final static String CONTENT_TYPE = "VersionTracking";
@@ -49,7 +51,6 @@ public class VTSessionContentHandler extends DBContentHandler {
 				"Unsupported domain object: " + domainObject.getClass().getName());
 		}
 		return createFile((VTSessionDB) domainObject, CONTENT_TYPE, fs, path, name, monitor);
-
 	}
 
 	@Override
@@ -74,7 +75,7 @@ public class VTSessionContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public DomainObjectAdapter getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
+	public VTSessionDB getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
 			boolean okToUpgrade, boolean okToRecover, Object consumer, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException {
 
@@ -119,7 +120,7 @@ public class VTSessionContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public Class<? extends DomainObject> getDomainObjectClass() {
+	public Class<VTSessionDB> getDomainObjectClass() {
 		return VTSessionDB.class;
 	}
 
@@ -129,7 +130,7 @@ public class VTSessionContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public DomainObjectAdapter getImmutableObject(FolderItem item, Object consumer, int version,
+	public VTSessionDB getImmutableObject(FolderItem item, Object consumer, int version,
 			int minChangeVersion, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException {
 
@@ -149,7 +150,7 @@ public class VTSessionContentHandler extends DBContentHandler {
 	}
 
 	@Override
-	public DomainObjectAdapter getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
+	public VTSessionDB getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
 			Object consumer, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException {
 

Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/actions/OpenVersionTrackingSessionAction.java

@@ -15,6 +15,10 @@
  */
 package ghidra.feature.vt.gui.actions;
 
+import docking.ActionContext;
+import docking.action.DockingAction;
+import docking.action.MenuData;
+import docking.tool.ToolConstants;
 import ghidra.feature.vt.api.main.VTSession;
 import ghidra.feature.vt.gui.plugin.VTController;
 import ghidra.feature.vt.gui.plugin.VTPlugin;
@@ -23,10 +27,6 @@ import ghidra.framework.model.DomainFile;
 import ghidra.framework.model.DomainFileFilter;
 import ghidra.framework.plugintool.PluginTool;
 import ghidra.util.HelpLocation;
-import docking.ActionContext;
-import docking.action.DockingAction;
-import docking.action.MenuData;
-import docking.tool.ToolConstants;
 
 public class OpenVersionTrackingSessionAction extends DockingAction {
 
@@ -60,5 +60,10 @@ public class OpenVersionTrackingSessionAction extends DockingAction {
 			Class<?> c = f.getDomainObjectClass();
 			return VTSession.class.isAssignableFrom(c);
 		}
+
+		@Override
+		public boolean followLinkedFolders() {
+			return false;
+		}
 	}
 }

Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/wizard/NewSessionPanel.java

@@ -29,6 +29,7 @@ import docking.widgets.label.GDLabel;
 import docking.wizard.*;
 import generic.theme.*;
 import ghidra.app.util.task.OpenProgramTask;
+import ghidra.app.util.task.OpenProgramTask.OpenProgramRequest;
 import ghidra.framework.main.DataTreeDialog;
 import ghidra.framework.model.DomainFile;
 import ghidra.framework.model.DomainFolder;
@@ -383,8 +384,8 @@ public class NewSessionPanel extends AbstractMageJPanel<VTWizardStateKey> {
 
 		OpenProgramTask openProgramTask = new OpenProgramTask(programInfo.getFile(), tool);
 		new TaskLauncher(openProgramTask, tool.getActiveWindow());
-		Program program = openProgramTask.getOpenProgram();
+		OpenProgramRequest openProgram = openProgramTask.getOpenProgram();
-		programInfo.setProgram(program);
+		programInfo.setProgram(openProgram != null ? openProgram.getProgram() : null);
 	}
 
 	@Override

Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/gui/wizard/VTWizardUtils.java

@@ -20,12 +20,12 @@ import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 
 import docking.widgets.OptionDialog;
-import ghidra.feature.vt.api.impl.VTSessionContentHandler;
+import ghidra.feature.vt.api.main.VTSession;
 import ghidra.feature.vt.gui.task.SaveTask;
 import ghidra.framework.main.DataTreeDialog;
 import ghidra.framework.model.DomainFile;
 import ghidra.framework.model.DomainFileFilter;
-import ghidra.program.database.ProgramDB;
+import ghidra.program.model.listing.Program;
 import ghidra.util.HTMLUtilities;
 import ghidra.util.task.TaskLauncher;
 
@@ -36,23 +36,20 @@ public class VTWizardUtils {
 	}
 
 	public static final DomainFileFilter VT_SESSION_FILTER = new DomainFileFilter() {
+
 		@Override
 		public boolean accept(DomainFile df) {
-			if (VTSessionContentHandler.CONTENT_TYPE.equals(df.getContentType())) {
+			return VTSession.class.isAssignableFrom(df.getDomainObjectClass());
-				return true;
 		}
+
+		@Override
+		public boolean followLinkedFolders() {
 			return false;
 		}
 	};
 
-	public static final DomainFileFilter PROGRAM_FILTER = new DomainFileFilter() {
+	public static final DomainFileFilter PROGRAM_FILTER = f -> {
-		@Override
+		return Program.class.isAssignableFrom(f.getDomainObjectClass());
-		public boolean accept(DomainFile df) {
-			if (ProgramDB.CONTENT_TYPE.equals(df.getContentType())) {
-				return true;
-			}
-			return false;
-		}
 	};
 
 	static DomainFile chooseDomainFile(Component parent, String domainIdentifier,

Ghidra/Framework/DB/src/main/java/db/buffers/BufferFileAdapter.java

@@ -16,8 +16,7 @@
 package db.buffers;
 
 import java.io.IOException;
-import java.rmi.NoSuchObjectException;
+import java.rmi.*;
-import java.rmi.Remote;
 import java.util.NoSuchElementException;
 
 import ghidra.util.Msg;
@@ -104,8 +103,8 @@ public class BufferFileAdapter implements BufferFile {
 			bufferFileHandle.dispose();
 		}
 		catch (IOException e) {
-			// handle may have already been disposed
+			// handle may have already been disposed or disconnected
-			if (!(e instanceof NoSuchObjectException)) {
+			if (!(e instanceof NoSuchObjectException) && !(e instanceof ConnectException)) {
 				Msg.error(this, e);
 			}
 		}

Ghidra/Framework/Docking/src/main/java/docking/widgets/tree/GTreeNode.java

@@ -16,6 +16,7 @@
 package docking.widgets.tree;
 
 import java.util.*;
+import java.util.function.Predicate;
 import java.util.stream.Stream;
 
 import javax.swing.Icon;
@@ -197,6 +198,22 @@ public abstract class GTreeNode extends CoreGTreeNode implements Comparable<GTre
 		return null;
 	}
 
+	/**
+	 * Returns the child node of this node with the given name which satisfies predicate filter.
+	 * 
+	 * @param name the name of the child to be returned
+	 * @param filter predicate filter
+	 * @return the child with the given name
+	 */
+	public GTreeNode getChild(String name, Predicate<GTreeNode> filter) {
+		for (GTreeNode node : children()) {
+			if (name.equals(node.getName()) && filter.test(node)) {
+				return node;
+			}
+		}
+		return null;
+	}
+
 	/**
 	 * Returns the child node at the given index. Returns null if the index is out of bounds.
 	 * 
@@ -488,6 +505,15 @@ public abstract class GTreeNode extends CoreGTreeNode implements Comparable<GTre
 		}
 	}
 
+	/**
+	 * Determine if this node may be auto-expanded.  Some special node cases may need to prevent
+	 * or limit auto-expansion due to tree depth or other special conditions.
+	 * @return true if this node allows auto-expansion, else false.
+	 */
+	public boolean isAutoExpandPermitted() {
+		return !isLeaf();
+	}
+
 	/**
 	 * Convenience method for collapsing (closing) this node in the tree. If this node is not
 	 * currently attached to a visible tree, then this call does nothing

Ghidra/Framework/Docking/src/main/java/docking/widgets/tree/tasks/GTreeExpandAllTask.java

@@ -42,14 +42,24 @@ public class GTreeExpandAllTask extends GTreeTask {
 		monitor.initialize(1000);
 		monitor.setMessage("Expanding nodes...");
 		try {
-			expandNode(node, monitor);
+			expandNode(node, true, monitor);
 		}
 		catch (CancelledException e) {
 			// Not everything expanded which is ok
 		}
 	}
 
-	protected void expandNode(GTreeNode parent, TaskMonitor monitor) throws CancelledException {
+	/**
+	 * Expand the specified parent tree node.
+	 * @param parent the tree node to be expanded
+	 * @param force if parent node has auto-expand disabled 
+	 * (see {@link GTreeNode#isAutoExpandPermitted()}) passing true will force such a node to 
+	 * expand, false will respect this restriction and not expand the parent node.
+	 * @param monitor task monitor
+	 * @throws CancelledException if task cancelled
+	 */
+	protected void expandNode(GTreeNode parent, boolean force, TaskMonitor monitor)
+			throws CancelledException {
 		// only expand MAX number of nodes.
 		if (monitor.getProgress() >= MAX) {
 			return;
@@ -57,6 +67,9 @@ public class GTreeExpandAllTask extends GTreeTask {
 		if (parent.isLeaf()) {
 			return;
 		}
+		if (!force && !parent.isAutoExpandPermitted()) {
+			return;
+		}
 		monitor.checkCanceled();
 		List<GTreeNode> allChildren = parent.getChildren();
 		if (allChildren.size() == 0) {
@@ -68,9 +81,9 @@ public class GTreeExpandAllTask extends GTreeTask {
 		}
 		for (GTreeNode child : allChildren) {
 			monitor.checkCanceled();
-			expandNode(child, monitor);
+			expandNode(child, false, monitor);
 		}
-		monitor.incrementProgress(1);
+		monitor.incrementProgress(1); // TODO: total node count is unknown
 	}
 
 	private void expandPath(final TreePath treePath, final TaskMonitor monitor) {

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/client/RepositoryAdapter.java

@@ -158,8 +158,10 @@ public class RepositoryAdapter implements RemoteAdapterListener {
 
 	/**
 	 * Attempt to connect to the server.
+	 * @throws RepositoryNotFoundException if named repository does not exist
+	 * @throws IOException if IO error occurs
 	 */
-	public void connect() throws IOException {
+	public void connect() throws RepositoryNotFoundException, IOException {
 		synchronized (serverAdapter) {
 			if (repository != null) {
 				try {
@@ -180,7 +182,7 @@ public class RepositoryAdapter implements RemoteAdapterListener {
 				unexpectedDisconnect = false;
 				if (repository == null) {
 					noSuchRepository = true;
-					throw new IOException("Repository '" + name + "': not found");
+					throw new RepositoryNotFoundException("Repository '" + name + "': not found");
 				}
 				Msg.info(this, "Connected to repository '" + name + "'");
 				changeDispatcher.start();

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/client/RepositoryNotFoundException.java

@@ -0,0 +1,31 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.client;
+
+import java.io.IOException;
+
+/**
+ * {@code RepositoryNotFoundException} thrown when a failed connection occurs to a
+ * non-existing repository.  A valid server connection is required to make this 
+ * determination.
+ */
+public class RepositoryNotFoundException extends IOException {
+
+	public RepositoryNotFoundException(String msg) {
+		super(msg);
+	}
+
+}

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/client/RepositoryServerAdapter.java

@@ -52,6 +52,9 @@ public class RepositoryServerAdapter {
 	// Keeps track of whether the connection attempt was cancelled by the user
 	private boolean connectCancelled = false;
 
+	// Keep track of last connect error
+	private Throwable lastConnectError;
+
 	private WeakSet<RemoteAdapterListener> listenerList =
 		WeakDataStructureFactory.createCopyOnWriteWeakSet();
 
@@ -105,6 +108,14 @@ public class RepositoryServerAdapter {
 		return connectCancelled;
 	}
 
+	/**
+	 * Returns the last error associated with a failed connection attempt.
+	 * @return last connect error or null
+	 */
+	public Throwable getLastConnectError() {
+		return lastConnectError;
+	}
+
 	/**
 	 * Notify listeners of a connection state change.
 	 */
@@ -135,7 +146,7 @@ public class RepositoryServerAdapter {
 			}
 		}
 
-		Throwable cause = null;
+		lastConnectError = null;
 		try {
 			try {
 				serverHandle = ClientUtil.connect(server);
@@ -162,22 +173,22 @@ public class RepositoryServerAdapter {
 		catch (LoginException e) {
 			Msg.showError(this, null, "Server Error",
 				"Server access denied (" + serverInfoStr + ").");
-			cause = e;
+			lastConnectError = e;
 		}
 		catch (GeneralSecurityException e) {
 			Msg.showError(this, null, "Server Error",
 				"Server access denied (" + serverInfoStr + "): " + e.getMessage());
-			cause = e;
+			lastConnectError = e;
 		}
 		catch (SocketTimeoutException | java.net.ConnectException | java.rmi.ConnectException e) {
 			Msg.showError(this, null, "Server Error",
 				"Connection to server failed (" + server + ").");
-			cause = e;
+			lastConnectError = e;
 		}
 		catch (java.net.UnknownHostException | java.rmi.UnknownHostException e) {
 			Msg.showError(this, null, "Server Error",
 				"Server Not Found (" + server.getServerName() + ").");
-			cause = e;
+			lastConnectError = e;
 		}
 		catch (RemoteException e) {
 			String msg = e.getMessage();
@@ -185,7 +196,7 @@ public class RepositoryServerAdapter {
 			while ((t = t.getCause()) != null) {
 				String err = t.getMessage();
 				msg = err != null ? err : t.toString();
-				cause = t;
+				lastConnectError = t;
 			}
 			Msg.showError(this, null, "Server Error",
 				"An error occurred on the server (" + serverInfoStr + ").\n" + msg, e);
@@ -200,7 +211,7 @@ public class RepositoryServerAdapter {
 				"An error occurred while connecting to the server (" + serverInfoStr + ").\n" + msg,
 				e);
 		}
-		throw new NotConnectedException("Not connected to repository server", cause);
+		throw new NotConnectedException("Not connected to repository server", lastConnectError);
 	}
 
 	private void checkPasswordExpiration() {

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/remote/RepositoryHandle.java

@@ -32,7 +32,7 @@ public interface RepositoryHandle {
 
 	// TODO: NOTE! Debugging client or sever garbage collection delays could
 	// cause handle to be disposed prematurely.
-	public final static int CLIENT_CHECK_PERIOD = SystemUtilities.isInTestingMode() ? 1000 : 30000;
+	public final static int CLIENT_CHECK_PERIOD = SystemUtilities.isInTestingMode() ? 2000 : 30000;
 
 	/**
 	 * Returns the name of this repository.

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/FileSystemEventManager.java

@@ -22,41 +22,69 @@ import java.util.concurrent.*;
  * <code>FileSystemListenerList</code> maintains a list of FileSystemListener's.
  * This class, acting as a FileSystemListener, simply relays each callback to
  * all FileSystemListener's within its list.  Employs either a synchronous 
- * and asynchronous notification mechanism.
+ * and asynchronous notification mechanism. Once disposed event dispatching will 
+ * discontinue.
  */
 public class FileSystemEventManager implements FileSystemListener {
 
+	private static enum ThreadState {
+		STOPPED, RUNNING, DISPOSED
+	}
+
 	private List<FileSystemListener> listeners = new CopyOnWriteArrayList<>();
 	private BlockingQueue<FileSystemEvent> eventQueue = new LinkedBlockingQueue<>();
 
-	private volatile boolean disposed = false;
+	private final boolean asyncDispatchEnabled;
+
+	private volatile ThreadState state = ThreadState.STOPPED;
 	private Thread thread;
 
 	/**
 	 * Constructor
 	 * @param enableAsynchronousDispatching if true a separate dispatch thread will be used
-	 * to notify listeners.  If false, blocking notification will be performed.
+	 * to notify listeners.  If false, blocking notification will be performed.  Events are 
+	 * immediately discarded in the absence of any listener(s).
 	 */
 	public FileSystemEventManager(boolean enableAsynchronousDispatching) {
+		asyncDispatchEnabled = enableAsynchronousDispatching;
+	}
 
-		if (enableAsynchronousDispatching) {
+	/**
+	 * Return true if asynchornous event processing is enabled.
+	 * @return true if asynchornous event processing is enabled, else false
+	 */
+	public boolean isAsynchronous() {
+		return asyncDispatchEnabled;
+	}
+
+	/**
+	 * Discontinue event dispatching and terminate dispatch thread if it exists.
+	 */
+	public synchronized void dispose() {
+		state = ThreadState.DISPOSED;
+		if (asyncDispatchEnabled) {
+			if (thread != null && thread.isAlive()) {
+				thread.interrupt();
+			}
+			eventQueue.clear();
+		}
+	}
+
+	private synchronized void startDispatchThread() {
+		if (asyncDispatchEnabled && state == ThreadState.STOPPED) {
+			// only starts when first listener is added
+			state = ThreadState.RUNNING;
 			thread = new FileSystemEventProcessingThread();
 			thread.start();
 		}
 	}
 
-	public void dispose() {
-		disposed = true;
-		if (thread != null) {
-			thread.interrupt();
-		}
-	}
-
 	/**
 	 * Add a listener to this list.
 	 * @param listener the listener
 	 */
 	public void add(FileSystemListener listener) {
+		startDispatchThread(); // if asyncDispatchEnabled
 		listeners.add(listener);
 	}
 
@@ -116,30 +144,34 @@ public class FileSystemEventManager implements FileSystemListener {
 	@Override
 	public void syncronize() {
 		// Note: synchronize calls will only work when using a threaded event queue
-		if (isAsynchronous()) {
+		if (asyncDispatchEnabled) {
-			add(new SynchronizeEvent());
+			queueEvent(new SynchronizeEvent());
 		}
 	}
 
-	private boolean isAsynchronous() {
+	/**
-		return thread != null;
+	 * Queue specified event if listener thread is running
-	}
+	 * @param ev filesystm event
-
+	 * @return true if queued, else false if listener thread not running
-	private void add(FileSystemEvent ev) {
+	 */
-		if (!listeners.isEmpty()) {
+	private boolean queueEvent(FileSystemEvent ev) {
-			eventQueue.add(ev);
+		if (state == ThreadState.RUNNING) {
+			return eventQueue.add(ev);
 		}
+		return false;
 	}
 
 	private void handleEvent(FileSystemEvent e) {
-		if (disposed) {
+		if (state == ThreadState.DISPOSED) {
 			return;
 		}
 
-		if (isAsynchronous()) {
+		if (asyncDispatchEnabled) {
-			add(e);
+			// if there are no listeners event will be discarded (i.e., listener thread not running)
+			queueEvent(e);
 		}
 		else {
+			// process in a synchronous fashion in current thread
 			e.process(listeners);
 		}
 	}
@@ -154,18 +186,27 @@ public class FileSystemEventManager implements FileSystemListener {
 	 * 
 	 * @param timeout the maximum time to wait
 	 * @param unit the time unit of the {@code time} argument
-	 * @return true if the events were processed in the given timeout
+	 * @return true if the events were processed in the given timeout.  A false value will be
-	 * @throws InterruptedException if this waiting thread is interrupted
+	 * returned if either a timeout occured
 	 */
-	public boolean flushEvents(long timeout, TimeUnit unit) throws InterruptedException {
+	public boolean flushEvents(long timeout, TimeUnit unit) {
-		if (!isAsynchronous()) {
+		if (!asyncDispatchEnabled) {
 			return true; // each thread processes its own event
 		}
 
 		MarkerEvent event = new MarkerEvent();
-		eventQueue.add(event);
+		if (!queueEvent(event)) {
+			// events are not queuing since there are no listeners or dispose has occured
+			return true;
+		}
+		try {
 			return event.waitForEvent(timeout, unit);
 		}
+		catch (InterruptedException e) {
+			// ignore - listener thread stopped or disposed
+			return true;
+		}
+	}
 
 //==================================================================================================
 // Inner Classes
@@ -180,18 +221,14 @@ public class FileSystemEventManager implements FileSystemListener {
 
 		@Override
 		public void run() {
-			while (!disposed) {
+			while (state == ThreadState.RUNNING) {
-
 				FileSystemEvent event;
 				try {
 					event = eventQueue.take();
 					event.process(listeners);
 				}
 				catch (InterruptedException e) {
-					// interrupt has been cleared; if other threads rely on this interrupted state,
+					// ignore - interrupt has been cleared
-					// then mark the thread as interrupted again by calling: 
-					// Thread.currentThread().interrupt();
-					// For now, this code relies on the 'alive' flag to know when to terminate
 				}
 			}
 		}

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/local/IndexedLocalFileSystem.java

@@ -916,6 +916,7 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 
 	@Override
 	public int getItemCount() throws IOException {
+		checkDisposed();
 		if (readOnly) {
 			refreshReadOnlyIndex();
 		}
@@ -930,11 +931,9 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		return count;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#getFolders(java.lang.String)
-	 */
 	@Override
 	public synchronized String[] getFolderNames(String folderPath) throws IOException {
+		checkDisposed();
 		if (readOnly) {
 			refreshReadOnlyIndex();
 		}
@@ -948,13 +947,12 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		}
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#createFolder(java.lang.String, java.lang.String)
-	 */
 	@Override
 	public synchronized void createFolder(String parentPath, String folderName)
 			throws InvalidNameException, IOException {
 
+		checkDisposed();
+
 		if (readOnly) {
 			throw new ReadOnlyException();
 		}
@@ -987,12 +985,11 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		eventManager.folderCreated(parentPath, getName(path));
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#deleteFolder(java.lang.String)
-	 */
 	@Override
 	public synchronized void deleteFolder(String folderPath) throws IOException {
 
+		checkDisposed();
+
 		if (readOnly) {
 			throw new ReadOnlyException();
 		}
@@ -1059,13 +1056,12 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		getListener().itemCreated(destFolderPath, itemName);
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#moveItem(java.lang.String, java.lang.String, java.lang.String)
-	 */
 	@Override
 	public synchronized void moveItem(String folderPath, String name, String newFolderPath,
 			String newName) throws IOException, InvalidNameException {
 
+		checkDisposed();
+
 		if (readOnly) {
 			throw new ReadOnlyException();
 		}
@@ -1140,13 +1136,12 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		deleteEmptyVersionedFolders(folderPath);
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#moveFolder(java.lang.String, java.lang.String, java.lang.String)
-	 */
 	@Override
 	public synchronized void moveFolder(String parentPath, String folderName, String newParentPath)
 			throws InvalidNameException, IOException {
 
+		checkDisposed();
+
 		if (readOnly) {
 			throw new ReadOnlyException();
 		}
@@ -1206,13 +1201,12 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		}
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#renameFolder(java.lang.String, java.lang.String, java.lang.String)
-	 */
 	@Override
 	public synchronized void renameFolder(String parentPath, String folderName,
 			String newFolderName) throws InvalidNameException, IOException {
 
+		checkDisposed();
+
 		if (readOnly) {
 			throw new ReadOnlyException();
 		}
@@ -1247,16 +1241,14 @@ public class IndexedLocalFileSystem extends LocalFileSystem {
 		eventManager.folderRenamed(parentPath, folderName, newFolderName);
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#folderExists(java.lang.String)
-	 */
 	@Override
 	public synchronized boolean folderExists(String folderPath) {
 		try {
+			checkDisposed();
 			getFolder(folderPath, GetFolderOption.READ_ONLY);
 			return true;
 		}
-		catch (NotFoundException e) {
+		catch (IOException | NotFoundException e) {
 			return false;
 		}
 	}

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/local/IndexedV1LocalFileSystem.java

@@ -46,7 +46,7 @@ public class IndexedV1LocalFileSystem extends IndexedLocalFileSystem {
 	 * @throws FileNotFoundException if specified rootPath does not exist
 	 * @throws IOException if error occurs while reading/writing index files
 	 */
-	IndexedV1LocalFileSystem(String rootPath, boolean isVersioned, boolean readOnly,
+	protected IndexedV1LocalFileSystem(String rootPath, boolean isVersioned, boolean readOnly,
 			boolean enableAsyncronousDispatching, boolean create) throws IOException {
 		super(rootPath, isVersioned, readOnly, enableAsyncronousDispatching, create);
 	}
@@ -134,6 +134,7 @@ public class IndexedV1LocalFileSystem extends IndexedLocalFileSystem {
 
 	@Override
 	public FolderItem getItem(String fileID) throws IOException, UnsupportedOperationException {
+		checkDisposed();
 		if (fileIdMap == null) {
 			return null;
 		}

Ghidra/Framework/FileSystem/src/main/java/ghidra/framework/store/local/LocalFileSystem.java

@@ -71,6 +71,8 @@ public abstract class LocalFileSystem implements FileSystem {
 
 	private static boolean refreshRequired = false;
 
+	private boolean disposed = false;
+
 	protected final File root;
 	protected final boolean isVersioned;
 	protected final boolean readOnly;
@@ -78,9 +80,6 @@ public abstract class LocalFileSystem implements FileSystem {
 
 	private RepositoryLogger repositoryLogger;
 
-	// Always false in production; can be manipulated by tests
-	private boolean isShared;
-
 	/**
 	 * Construct a local filesystem for existing data
 	 * @param rootPath
@@ -285,25 +284,16 @@ public abstract class LocalFileSystem implements FileSystem {
 		return refreshRequired;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#isVersioned()
-	 */
 	@Override
 	public boolean isVersioned() {
 		return isVersioned;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#isOnline()
-	 */
 	@Override
 	public boolean isOnline() {
-		return true;
+		return !disposed;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#isReadOnly()
-	 */
 	@Override
 	public boolean isReadOnly() {
 		return readOnly;
@@ -388,9 +378,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		return getItemNames(folderPath, false);
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#getItem(java.lang.String, java.lang.String)
-	 */
 	@Override
 	public synchronized LocalFolderItem getItem(String folderPath, String name) throws IOException {
 		try {
@@ -424,9 +411,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		throw new UnsupportedOperationException("getItem by File-ID");
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#createDatabase(java.lang.String, java.lang.String, java.lang.String, db.buffers.BufferFile, java.lang.String, java.lang.String, boolean, ghidra.util.task.TaskMonitor, java.lang.String)
-	 */
 	@Override
 	public synchronized LocalDatabaseItem createDatabase(String parentPath, String name,
 			String fileID, BufferFile bufferFile, String comment, String contentType,
@@ -483,9 +467,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		return item;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#createDatabase(java.lang.String, java.lang.String, java.lang.String, int, java.lang.String)
-	 */
 	@Override
 	public LocalManagedBufferFile createDatabase(String parentPath, String name, String fileID,
 			String contentType, int bufferSize, String user, String projectPath)
@@ -513,9 +494,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		return bufferFile;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#createDataFile(java.lang.String, java.lang.String, java.io.InputStream, java.lang.String, java.lang.String, ghidra.util.task.TaskMonitor)
-	 */
 	@Override
 	public synchronized LocalDataFile createDataFile(String parentPath, String name,
 			InputStream istream, String comment, String contentType, TaskMonitor monitor)
@@ -546,9 +524,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		return dataFile;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#createFile(java.lang.String, java.lang.String, java.io.File, ghidra.util.task.TaskMonitor, java.lang.String)
-	 */
 	@Override
 	public LocalDatabaseItem createFile(String parentPath, String name, File packedFile,
 			TaskMonitor monitor, String user)
@@ -591,9 +566,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		return item;
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#moveItem(java.lang.String, java.lang.String, java.lang.String)
-	 */
 	@Override
 	public synchronized void moveItem(String folderPath, String name, String newFolderPath,
 			String newName) throws IOException, InvalidNameException {
@@ -652,9 +624,6 @@ public abstract class LocalFileSystem implements FileSystem {
 	@Override
 	public abstract boolean folderExists(String folderPath);
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#fileExists(java.lang.String, java.lang.String)
-	 */
 	@Override
 	public boolean fileExists(String folderPath, String name) {
 		try {
@@ -669,9 +638,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		}
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#addFileSystemListener(ghidra.framework.store.FileSystemListener)
-	 */
 	@Override
 	public void addFileSystemListener(FileSystemListener listener) {
 		if (eventManager != null) {
@@ -679,9 +645,6 @@ public abstract class LocalFileSystem implements FileSystem {
 		}
 	}
 
-	/*
-	 * @see ghidra.framework.store.FileSystem#removeFileSystemListener(ghidra.framework.store.FileSystemListener)
-	 */
 	@Override
 	public void removeFileSystemListener(FileSystemListener listener) {
 		if (eventManager != null) {
@@ -829,8 +792,7 @@ public abstract class LocalFileSystem implements FileSystem {
 
 	@Override
 	public boolean isShared() {
-		// Does not support direct sharing in production
+		return false;
-		return isShared;
 	}
 
 //	static void testValidPathLength(File file) throws IOException {
@@ -846,6 +808,17 @@ public abstract class LocalFileSystem implements FileSystem {
 		if (eventManager != null) {
 			eventManager.dispose();
 		}
+		disposed = true;
+	}
+
+	/**
+	 * Check to see if file-system has been disposed.
+	 * @throws IOException if file-system has been disposed
+	 */
+	protected void checkDisposed() throws IOException {
+		if (disposed) {
+			throw new IOException("File-system has been disposed");
+		}
 	}
 
 	public boolean migrationInProgress() {

Ghidra/Framework/FileSystem/src/test.slow/java/ghidra/framework/store/local/AbstractLocalFileSystemTest.java

@@ -929,13 +929,8 @@ public abstract class AbstractLocalFileSystemTest extends AbstractGenericTest {
 		FileSystemEventManager eventManager =
 			(FileSystemEventManager) TestUtils.getInstanceField("eventManager", fs);
 
-		try {
 		eventManager.flushEvents(DEFAULT_WAIT_TIMEOUT, TimeUnit.MILLISECONDS);
 	}
-		catch (InterruptedException e) {
-			failWithException("Interrupted waiting for filesystem events", e);
-		}
-	}
 }
 
 class MyEvent {

Ghidra/Framework/Generic/src/main/java/generic/test/AbstractGenericTest.java

@@ -507,6 +507,41 @@ public abstract class AbstractGenericTest extends AbstractGTest {
 		return null;
 	}
 
+	public static <T extends Component> List<T> findComponents(Container parent,
+			Class<T> desiredClass) {
+		return findComponents(parent, desiredClass, false);
+	}
+
+	public static <T extends Component> List<T> findComponents(Container parent,
+			Class<T> desiredClass, boolean checkOwnedWindows) {
+		Component[] comps = parent.getComponents();
+		List<T> list = new ArrayList<>();
+		for (Component element : comps) {
+			if (element == null) {
+				continue;// this started happening in 1.6, not sure why
+			}
+			if (desiredClass.isAssignableFrom(element.getClass())) {
+				list.add(desiredClass.cast(element));
+			}
+			else if (element instanceof Container) {
+				T c = findComponent((Container) element, desiredClass, checkOwnedWindows);
+				if (c != null) {
+					list.add(desiredClass.cast(c));
+				}
+			}
+		}
+		if (checkOwnedWindows && (parent instanceof Window)) {
+			Window[] windows = ((Window) parent).getOwnedWindows();
+			for (int i = windows.length - 1; i >= 0; i--) {
+				Component c = findComponent(windows[i], desiredClass, checkOwnedWindows);
+				if (c != null) {
+					list.add(desiredClass.cast(c));
+				}
+			}
+		}
+		return list;
+	}
+
 	/**
 	 * Get the first field object contained within object ownerInstance which
 	 * has the type classType. This method is only really useful if it is known

Ghidra/Framework/Generic/src/main/java/generic/util/FileChannelLock.java

@@ -1,6 +1,5 @@
 /* ###
  * IP: GHIDRA
- * REVIEWED: YES
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,8 +16,7 @@
 package generic.util;
 
 import java.io.*;
-import java.nio.channels.FileChannel;
+import java.nio.channels.*;
-import java.nio.channels.FileLock;
 
 public class FileChannelLock {
 
@@ -51,7 +49,7 @@ public class FileChannelLock {
 
 			return isLocked;
 		}
-		catch (IOException e) {
+		catch (IOException | OverlappingFileLockException e) {
 			release();
 		}
 		return false;

Ghidra/Framework/Project/certification.manifest

@@ -36,6 +36,7 @@ src/main/resources/images/disconnected.gif||GHIDRA||reviewed||END|
 src/main/resources/images/disk.png||FAMFAMFAM Icons - CC 2.5||||END|
 src/main/resources/images/face-glasses.png||Tango Icons - Public Domain|||tango icon set|END|
 src/main/resources/images/folder_add.png||FAMFAMFAM Icons - CC 2.5|||famfamfam silk icon set|END|
+src/main/resources/images/link.png||Crystal Clear Icons - LGPL 2.1||||END|
 src/main/resources/images/lock.png||FAMFAMFAM Icons - CC 2.5|||famfamfam silk icon set|END|
 src/main/resources/images/monitor.png||FAMFAMFAM Icons - CC 2.5|||silk|END|
 src/main/resources/images/noneInTool.gif||GHIDRA||reviewed||END|

Ghidra/Framework/Project/data/project.icons.theme.properties

@@ -6,10 +6,14 @@ icon.project.data.file.ghidra.unsupported = unknownFile.gif
 icon.project.data.file.ghidra.checked.out = icon.check
 icon.project.data.file.ghidra.checked.out.exclusive = checkex.png
 icon.project.data.file.ghidra.hijacked = small_hijack.gif
-icon.project.data.file.ghidra.read.only = user-busy.png [size(10,10)]
+icon.project.data.file.ghidra.read.only = user-busy.png [size(8,8)]
 icon.project.data.file.ghidra.not.latest = checkNotLatest.gif
 
+icon.content.handler.link = link.png
+icon.content.handler.link.overlay = EMPTY_ICON[size(16,16)]{icon.content.handler.link[move(0,8)]} // lower-left of 16x16 icon
 
+icon.content.handler.linked.folder.open = icon.datatree.node.domain.folder.open{icon.content.handler.link.overlay}
+icon.content.handler.linked.folder.closed = icon.datatree.node.domain.folder.closed{icon.content.handler.link.overlay}
 
 [Dark Defaults]
 

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ContentHandler.java

@@ -19,9 +19,7 @@ import java.io.IOException;
 
 import javax.swing.Icon;
 
-import db.DBHandle;
+import ghidra.framework.model.*;
-import ghidra.framework.model.ChangeSet;
-import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.FileSystem;
 import ghidra.framework.store.FolderItem;
 import ghidra.util.InvalidNameException;
@@ -31,15 +29,17 @@ import ghidra.util.exception.VersionException;
 import ghidra.util.task.TaskMonitor;
 
 /**
- * NOTE:  ALL ContentHandler CLASSES MUST END IN "ContentHandler".  If not,
+ * NOTE:  ALL ContentHandler implementations MUST END IN "ContentHandler".  If not,
  * the ClassSearcher will not find them.
  * 
  * <code>ContentHandler</code> defines an application interface for converting 
  * between a specific domain object implementation and folder item storage. 
  * This interface also defines a method which provides an appropriate icon 
  * corresponding to the content.
+ * 
+ * @param <T> {@link DomainObjectAdapter} implementation class
  */
-public interface ContentHandler extends ExtensionPoint {
+public interface ContentHandler<T extends DomainObjectAdapter> extends ExtensionPoint {
 
 	public static final String UNKNOWN_CONTENT = "Unknown-File";
 	public static final String MISSING_CONTENT = "Missing-File";
@@ -56,7 +56,8 @@ public interface ContentHandler extends ExtensionPoint {
 	 * @param domainObject the domain object to store in the newly created folder item
 	 * @param monitor the monitor that allows the user to cancel
 	 * @return checkout ID for new item
-	 * @throws IOException if an i/o error occurs
+	 * @throws IOException if an IO error occurs or an unsupported {@code domainObject} 
+	 * implementation is specified.
 	 * @throws InvalidNameException if the specified name contains invalid characters
 	 * @throws CancelledException if the user cancels
 	 */
@@ -77,12 +78,12 @@ public interface ContentHandler extends ExtensionPoint {
 	 * set.
 	 * @param monitor the monitor that allows the user to cancel
 	 * @return immutable domain object
-	 * @throws IOException if a folder item access error occurs
+	 * @throws IOException if an IO or folder item access error occurs
 	 * @throws CancelledException if operation is cancelled by user
 	 * @throws VersionException if unable to handle file content due to version 
 	 * difference which could not be handled.
 	 */
-	DomainObjectAdapter getImmutableObject(FolderItem item, Object consumer, int version,
+	T getImmutableObject(FolderItem item, Object consumer, int version,
 			int minChangeVersion, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException;
 
@@ -98,12 +99,12 @@ public interface ContentHandler extends ExtensionPoint {
 	 * @param consumer consumer of the returned object
 	 * @param monitor the monitor that allows the user to cancel
 	 * @return read-only domain object
-	 * @throws IOException if a folder item access error occurs
+	 * @throws IOException if an IO or folder item access error occurs
 	 * @throws CancelledException if operation is cancelled by user
 	 * @throws VersionException if unable to handle file content due to version 
 	 * difference which could not be handled.
 	 */
-	DomainObjectAdapter getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
+	T getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
 			Object consumer, TaskMonitor monitor)
 			throws IOException, VersionException, CancelledException;
 
@@ -121,12 +122,12 @@ public interface ContentHandler extends ExtensionPoint {
 	 * @param consumer consumer of the returned object
 	 * @param monitor cancelable task monitor
 	 * @return updateable domain object
-	 * @throws IOException if a folder item access error occurs
+	 * @throws IOException if an IO or folder item access error occurs
 	 * @throws CancelledException if operation is cancelled by user
 	 * @throws VersionException if unable to handle file content due to version 
 	 * difference which could not be handled.
 	 */
-	DomainObjectAdapter getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
+	T getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
 			boolean okToUpgrade, boolean okToRecover, Object consumer, TaskMonitor monitor)
 			throws IOException, CancelledException, VersionException;
 
@@ -138,7 +139,7 @@ public interface ContentHandler extends ExtensionPoint {
 	 * @param newerVersion the newer version number
 	 * @return the set of changes that were made 
 	 * @throws VersionException if a database version change prevents reading of data.
-	 * @throws IOException if a folder item access error occurs or change set was 
+	 * @throws IOException if an IO or folder item access error occurs or change set was 
 	 * produced by newer version of software and can not be read
 	 */
 	ChangeSet getChangeSet(FolderItem versionedFolderItem, int olderVersion, int newerVersion)
@@ -161,55 +162,46 @@ public interface ContentHandler extends ExtensionPoint {
 	/**
 	 * Returns true if the content type is always private 
 	 * (i.e., can not be added to the versioned filesystem).
+	 * @return true if private content type, else false
 	 */
 	boolean isPrivateContentType();
 
 	/**
-	 * Returns list of unique content-types supported.
+	 * Returns a unique content-type identifier
-	 * A minimum of one content-type will be returned. If more than one
+	 * @return content type identifier for associated domain object(s).
-	 * is returned, these are considered equivalent aliases.
 	 */
 	String getContentType();
 
 	/**
 	 * A string that is meant to be presented to the user.
+	 * @return user friendly content type for associated domain object(s).
 	 */
 	String getContentTypeDisplayString();
 
 	/**
 	 * Returns the Icon associated with this handlers content type.
+	 * @return base icon to be used for a {@link DomainFile} with the associated content type.
 	 */
 	Icon getIcon();
 
 	/**
-	 * Returns the name of the default tool that should be used to open this content type
+	 * Returns the name of the default tool that should be used to open this content type.
+	 * @return associated default tool for this content type
 	 */
 	String getDefaultToolName();
 
 	/**
 	 * Returns domain object implementation class supported.
+	 * @return implementation class for the associated {@link DomainObjectAdapter} implementation.
 	 */
-	Class<? extends DomainObject> getDomainObjectClass();
+	Class<T> getDomainObjectClass();
 
 	/**
-	 * Create user data file associated with existing content.
+	 * If linking is supported return an instanceof the appropriate {@link LinkHandler}.
-	 * This facilitates the lazy creation of the user data file.
+	 * @return corresponding link handler or null if not supported.
-	 * @param associatedDomainObj associated domain object corresponding to this content handler
-	 * @param userDbh user data handle
-	 * @param userfs private user data filesystem
-	 * @param monitor task monitor
-	 * @throws IOException if an access error occurs
-	 * @throws CancelledException if operation is cancelled by user
 	 */
-	void saveUserDataFile(DomainObject associatedDomainObj, DBHandle userDbh, FileSystem userfs,
+	default LinkHandler<?> getLinkHandler() {
-			TaskMonitor monitor) throws CancelledException, IOException;
+		return null;
-
+	}
-	/**
-	 * Remove user data file associated with an existing folder item.
-	 * @param item folder item
-	 * @param userFilesystem
-	 * @throws IOException if an access error occurs
-	 */
-	void removeUserDataFile(FolderItem item, FileSystem userFilesystem) throws IOException;
 
 }

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DBContentHandler.java

@@ -18,13 +18,10 @@ package ghidra.framework.data;
 import java.io.IOException;
 
 import db.DBHandle;
-import db.buffers.BufferFile;
 import db.buffers.ManagedBufferFile;
-import ghidra.framework.model.DomainFile;
-import ghidra.framework.model.DomainObject;
 import ghidra.framework.store.*;
-import ghidra.util.*;
+import ghidra.util.InvalidNameException;
-import ghidra.util.exception.AssertException;
+import ghidra.util.SystemUtilities;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.task.TaskMonitor;
 
@@ -32,8 +29,11 @@ import ghidra.util.task.TaskMonitor;
  * <code>DBContentHandler</code> provides an abstract ContentHandler for 
  * domain object content which is stored within a database file.
  * This class provides helper methods for working with database files.
+ * 
+ * @param <T> {@link DomainObjectAdapterDB} implementation class
  */
-public abstract class DBContentHandler implements ContentHandler {
+public abstract class DBContentHandler<T extends DomainObjectAdapterDB>
+		implements ContentHandler<T> {
 
 	/**
 	 * Create a new database file from an open database handle.
@@ -70,6 +70,7 @@ public abstract class DBContentHandler implements ContentHandler {
 					bf.delete();
 				}
 				catch (IOException e) {
+					// ignore
 				}
 				abortCreate(fs, path, name, checkoutId);
 			}
@@ -77,7 +78,7 @@ public abstract class DBContentHandler implements ContentHandler {
 		return checkoutId;
 	}
 
-	private void abortCreate(FileSystem fs, String path, String name, long checkoutId) {
+	protected void abortCreate(FileSystem fs, String path, String name, long checkoutId) {
 		try {
 			FolderItem item = fs.getItem(path, name);
 			if (item != null) {
@@ -92,98 +93,4 @@ public abstract class DBContentHandler implements ContentHandler {
 		}
 	}
 
-	/**
-	 * Return user data content type corresponding to associatedContentType.
-	 */
-	private static String getUserDataContentType(String associatedContentType) {
-		return associatedContentType + "UserData";
-	}
-
-	/**
-	 * @see ghidra.framework.data.ContentHandler#saveUserDataFile(ghidra.framework.model.DomainObject, db.DBHandle, ghidra.framework.store.FileSystem, ghidra.util.task.TaskMonitor)
-	 */
-	@Override
-	public final void saveUserDataFile(DomainObject domainObj, DBHandle userDbh, FileSystem userfs,
-			TaskMonitor monitor) throws CancelledException, IOException {
-		if (userfs.isVersioned()) {
-			throw new IllegalArgumentException("User data file-system may not be versioned");
-		}
-		String associatedContentType = getContentType();
-		DomainFile associatedDf = domainObj.getDomainFile();
-		if (associatedDf == null) {
-			throw new IllegalStateException("associated " + associatedContentType +
-				" file must be saved before user data can be saved");
-		}
-		String associatedFileID = associatedDf.getFileID();
-		if (associatedFileID == null) {
-			Msg.error(this, associatedContentType + " '" + associatedDf.getName() +
-				"' has not been assigned a file ID, user settings can not be saved!");
-			return;
-		}
-		String path = "/";
-		String name = ProjectFileManager.getUserDataFilename(associatedFileID);
-		BufferFile bf = null;
-		boolean success = false;
-		try {
-			bf =
-				userfs.createDatabase(path, name, FileIDFactory.createFileID(),
-					getUserDataContentType(associatedContentType), userDbh.getBufferSize(),
-					SystemUtilities.getUserName(), null);
-			userDbh.saveAs(bf, true, monitor);
-			success = true;
-		}
-		catch (InvalidNameException e) {
-			throw new AssertException("Unexpected Error", e);
-		}
-		finally {
-			if (bf != null && !success) {
-				try {
-					bf.delete();
-				}
-				catch (IOException e) {
-				}
-				abortCreate(userfs, path, name, FolderItem.DEFAULT_CHECKOUT_ID);
-			}
-		}
-	}
-
-	/**
-	 * @see ghidra.framework.data.ContentHandler#removeUserDataFile(ghidra.framework.store.FolderItem, ghidra.framework.store.FileSystem)
-	 */
-	@Override
-	public final void removeUserDataFile(FolderItem associatedItem, FileSystem userfs)
-			throws IOException {
-		String path = "/";
-		String name = ProjectFileManager.getUserDataFilename(associatedItem.getFileID());
-		FolderItem item = userfs.getItem(path, name);
-		if (item != null) {
-			item.delete(-1, null);
-		}
-	}
-
-	/**
-	 * Open user data file associatedDbh
-	 * @param associatedFileID
-	 * @param associatedContentType
-	 * @param userfs
-	 * @param monitor
-	 * @return user data file database handle
-	 * @throws IOException
-	 * @throws CancelledException
-	 */
-	protected final DBHandle openAssociatedUserFile(String associatedFileID,
-			String associatedContentType, FileSystem userfs, TaskMonitor monitor)
-			throws IOException, CancelledException {
-		String path = "/";
-		String name = ProjectFileManager.getUserDataFilename(associatedFileID);
-		FolderItem item = userfs.getItem(path, name);
-		if (item == null || !(item instanceof DatabaseItem) ||
-			!getUserDataContentType(associatedContentType).equals(item.getContentType())) {
-			return null;
-		}
-		DatabaseItem dbItem = (DatabaseItem) item;
-		BufferFile bf = dbItem.openForUpdate(FolderItem.DEFAULT_CHECKOUT_ID);
-		return new DBHandle(bf, false, monitor);
-	}
-
 }

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DBWithUserDataContentHandler.java

@@ -0,0 +1,144 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.IOException;
+
+import db.DBHandle;
+import db.buffers.BufferFile;
+import ghidra.framework.model.DomainFile;
+import ghidra.framework.model.DomainObject;
+import ghidra.framework.store.*;
+import ghidra.util.*;
+import ghidra.util.exception.AssertException;
+import ghidra.util.exception.CancelledException;
+import ghidra.util.task.TaskMonitor;
+
+/**
+ * <code>DBContentHandler</code> provides an abstract ContentHandler for 
+ * domain object content which is stored within a database file.
+ * This class provides helper methods for working with database files.
+ * 
+ * @param <T> {@link DomainObjectAdapterDB} implementation class
+ */
+public abstract class DBWithUserDataContentHandler<T extends DomainObjectAdapterDB>
+		extends DBContentHandler<T> {
+
+	/**
+	 * Return user data content type corresponding to associatedContentType.
+	 */
+	private static String getUserDataContentType(String associatedContentType) {
+		return associatedContentType + "UserData";
+	}
+
+	/**
+	 * Create user data file associated with existing content.
+	 * This facilitates the lazy creation of the user data file.
+	 * @param associatedDomainObj associated domain object corresponding to this content handler
+	 * @param userDbh user data handle
+	 * @param userfs private user data filesystem
+	 * @param monitor task monitor
+	 * @throws IOException if an IO or access error occurs
+	 * @throws CancelledException if operation is cancelled by user
+	 */
+	public final void saveUserDataFile(DomainObject associatedDomainObj, DBHandle userDbh,
+			FileSystem userfs,
+			TaskMonitor monitor) throws CancelledException, IOException {
+		if (userfs.isVersioned()) {
+			throw new IllegalArgumentException("User data file-system may not be versioned");
+		}
+		String associatedContentType = getContentType();
+		DomainFile associatedDf = associatedDomainObj.getDomainFile();
+		if (associatedDf == null) {
+			throw new IllegalStateException("associated " + associatedContentType +
+				" file must be saved before user data can be saved");
+		}
+		String associatedFileID = associatedDf.getFileID();
+		if (associatedFileID == null) {
+			Msg.error(this, associatedContentType + " '" + associatedDf.getName() +
+				"' has not been assigned a file ID, user settings can not be saved!");
+			return;
+		}
+		String path = "/";
+		String name = ProjectFileManager.getUserDataFilename(associatedFileID);
+		BufferFile bf = null;
+		boolean success = false;
+		try {
+			bf =
+				userfs.createDatabase(path, name, FileIDFactory.createFileID(),
+					getUserDataContentType(associatedContentType), userDbh.getBufferSize(),
+					SystemUtilities.getUserName(), null);
+			userDbh.saveAs(bf, true, monitor);
+			success = true;
+		}
+		catch (InvalidNameException e) {
+			throw new AssertException("Unexpected Error", e);
+		}
+		finally {
+			if (bf != null && !success) {
+				try {
+					bf.delete();
+				}
+				catch (IOException e) {
+					// ignore
+				}
+				abortCreate(userfs, path, name, FolderItem.DEFAULT_CHECKOUT_ID);
+			}
+		}
+	}
+
+	/**
+	 * Remove user data file associated with an existing folder item.
+	 * @param associatedItem associated folder item
+	 * @param userFilesystem user data file system from which corresponding data should be removed.
+	 * @throws IOException if an access error occurs
+	 */
+	public final void removeUserDataFile(FolderItem associatedItem, FileSystem userFilesystem)
+			throws IOException {
+		String path = "/";
+		String name = ProjectFileManager.getUserDataFilename(associatedItem.getFileID());
+		FolderItem item = userFilesystem.getItem(path, name);
+		if (item != null) {
+			item.delete(-1, null);
+		}
+	}
+
+	/**
+	 * Open user data file associatedDbh
+	 * @param associatedFileID
+	 * @param associatedContentType
+	 * @param userfs
+	 * @param monitor
+	 * @return user data file database handle
+	 * @throws IOException
+	 * @throws CancelledException
+	 */
+	protected final DBHandle openAssociatedUserFile(String associatedFileID,
+			String associatedContentType, FileSystem userfs, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		String path = "/";
+		String name = ProjectFileManager.getUserDataFilename(associatedFileID);
+		FolderItem item = userfs.getItem(path, name);
+		if (item == null || !(item instanceof DatabaseItem) ||
+			!getUserDataContentType(associatedContentType).equals(item.getContentType())) {
+			return null;
+		}
+		DatabaseItem dbItem = (DatabaseItem) item;
+		BufferFile bf = dbItem.openForUpdate(FolderItem.DEFAULT_CHECKOUT_ID);
+		return new DBHandle(bf, false, monitor);
+	}
+
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainFileProxy.java

@@ -17,11 +17,14 @@ package ghidra.framework.data;
 
 import java.io.File;
 import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.*;
 
 import javax.swing.Icon;
 
 import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
 import ghidra.framework.store.ItemCheckoutStatus;
 import ghidra.framework.store.Version;
 import ghidra.framework.store.db.PackedDatabase;
@@ -111,6 +114,29 @@ public class DomainFileProxy implements DomainFile {
 		return parentPath + DomainFolder.SEPARATOR + getName();
 	}
 
+	@Override
+	public URL getSharedProjectURL() {
+		if (projectLocation != null && version == DomainFile.DEFAULT_VERSION) {
+			URL projectURL = projectLocation.getURL();
+			if (GhidraURL.isServerRepositoryURL(projectURL)) {
+				try {
+					// Direct URL construction done so that ghidra protocol 
+					// extension may be supported
+					String urlStr = projectURL.toExternalForm();
+					if (urlStr.endsWith("/")) {
+						urlStr = urlStr.substring(0, urlStr.length() - 1);
+					}
+					urlStr += getPathname();
+					return new URL(urlStr);
+				}
+				catch (MalformedURLException e) {
+					// ignore
+				}
+			}
+		}
+		return null;
+	}
+
 	@Override
 	public int compareTo(DomainFile df) {
 		return getName().compareToIgnoreCase(df.getName());
@@ -143,7 +169,7 @@ public class DomainFileProxy implements DomainFile {
 		DomainObjectAdapter dobj = getDomainObject();
 		if (dobj != null) {
 			try {
-				ContentHandler ch = DomainObjectAdapter.getContentHandler(dobj);
+				ContentHandler<?> ch = DomainObjectAdapter.getContentHandler(dobj);
 				return ch.getContentType();
 			}
 			catch (IOException e) {
@@ -153,6 +179,27 @@ public class DomainFileProxy implements DomainFile {
 		return "Unknown File";
 	}
 
+	@Override
+	public boolean isLinkFile() {
+		DomainObjectAdapter dobj = getDomainObject();
+		if (dobj != null) {
+			ContentHandler<?> ch;
+			try {
+				ch = DomainObjectAdapter.getContentHandler(dobj);
+				return LinkHandler.class.isAssignableFrom(ch.getClass());
+			}
+			catch (IOException e) {
+				// ignore
+			}
+		}
+		return false;
+	}
+
+	@Override
+	public DomainFolder followLink() {
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	public Class<? extends DomainObject> getDomainObjectClass() {
 		DomainObjectAdapter dobj = getDomainObject();
@@ -228,6 +275,7 @@ public class DomainFileProxy implements DomainFile {
 				dobj.release(consumer);
 			}
 			catch (IllegalArgumentException e) {
+				// ignore unknown consumer error
 			}
 		}
 	}
@@ -256,11 +304,6 @@ public class DomainFileProxy implements DomainFile {
 		throw new UnsupportedOperationException("Repository operations not supported");
 	}
 
-	@Override
-	public boolean isVersionControlSupported() {
-		return false;
-	}
-
 	@Override
 	public boolean canAddToRepository() {
 		return false;
@@ -303,6 +346,16 @@ public class DomainFileProxy implements DomainFile {
 		throw new UnsupportedOperationException("Repository operations not supported");
 	}
 
+	@Override
+	public boolean isLinkingSupported() {
+		return false;
+	}
+
+	@Override
+	public DomainFile copyToAsLink(DomainFolder newParent) throws IOException {
+		return null; // not supported by proxy file
+	}
+
 	@Override
 	public DomainFile copyTo(DomainFolder newParent, TaskMonitor monitor)
 			throws IOException, CancelledException {
@@ -318,11 +371,8 @@ public class DomainFileProxy implements DomainFile {
 		}
 	}
 
-	/**
-	 * @see ghidra.framework.model.DomainFile#copyVersionTo(int, ghidra.framework.model.DomainFolder, ghidra.util.task.TaskMonitor)
-	 */
 	@Override
-	public DomainFile copyVersionTo(int version, DomainFolder destFolder, TaskMonitor monitor)
+	public DomainFile copyVersionTo(int ver, DomainFolder destFolder, TaskMonitor monitor)
 			throws IOException, CancelledException {
 		throw new UnsupportedOperationException("copyVersionTo unsupported for DomainFileProxy");
 	}
@@ -420,7 +470,7 @@ public class DomainFileProxy implements DomainFile {
 			throw new UnsupportedOperationException("packFile() only valid for Database files");
 		}
 		DomainObjectAdapterDB dbObj = (DomainObjectAdapterDB) domainObj;
-		ContentHandler ch = DomainObjectAdapter.getContentHandler(domainObj);
+		ContentHandler<?> ch = DomainObjectAdapter.getContentHandler(domainObj);
 		PackedDatabase.packDatabase(dbObj.getDBHandle(), dbObj.getName(), ch.getContentType(), file,
 			monitor);
 	}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/DomainObjectAdapter.java

@@ -38,8 +38,8 @@ public abstract class DomainObjectAdapter implements DomainObject {
 	protected final static String DEFAULT_NAME = "untitled";
 
 	private static Class<?> defaultDomainObjClass; // Domain object implementation mapped to unknown content type
-	private static HashMap<String, ContentHandler> contentHandlerTypeMap; // maps content-type string to handler
+	private static HashMap<String, ContentHandler<?>> contentHandlerTypeMap; // maps content-type string to handler
-	private static HashMap<Class<?>, ContentHandler> contentHandlerClassMap; // maps domain object class to handler
+	private static HashMap<Class<?>, ContentHandler<?>> contentHandlerClassMap; // maps domain object class to handler
 	private static ChangeListener contentHandlerUpdateListener = new ChangeListener() {
 		@Override
 		public void stateChanged(ChangeEvent e) {
@@ -399,7 +399,7 @@ public abstract class DomainObjectAdapter implements DomainObject {
 				contentHandlerTypeMap.remove(null);
 			}
 			else {
-				ContentHandler ch = contentHandlerClassMap.get(doClass);
+				ContentHandler<?> ch = contentHandlerClassMap.get(doClass);
 				if (ch != null) {
 					contentHandlerTypeMap.put(null, ch);
 				}
@@ -414,9 +414,9 @@ public abstract class DomainObjectAdapter implements DomainObject {
 	 * @return content handler
 	 * @throws IOException if no content handler can be found
 	 */
-	static synchronized ContentHandler getContentHandler(String contentType) throws IOException {
+	static synchronized ContentHandler<?> getContentHandler(String contentType) throws IOException {
 		checkContentHandlerMaps();
-		ContentHandler ch = contentHandlerTypeMap.get(contentType);
+		ContentHandler<?> ch = contentHandlerTypeMap.get(contentType);
 		if (ch == null) {
 			throw new IOException("Content handler not found for " + contentType);
 		}
@@ -430,10 +430,10 @@ public abstract class DomainObjectAdapter implements DomainObject {
 	 * @return content handler
 	 * @throws IOException if no content handler can be found
 	 */
-	public static synchronized ContentHandler getContentHandler(DomainObject dobj)
+	public static synchronized ContentHandler<?> getContentHandler(DomainObject dobj)
 			throws IOException {
 		checkContentHandlerMaps();
-		ContentHandler ch = contentHandlerClassMap.get(dobj.getClass());
+		ContentHandler<?> ch = contentHandlerClassMap.get(dobj.getClass());
 		if (ch == null) {
 			throw new IOException("Content handler not found for " + dobj.getClass().getName());
 		}
@@ -450,17 +450,15 @@ public abstract class DomainObjectAdapter implements DomainObject {
 	}
 
 	private synchronized static void getContentHandlers() {
-		contentHandlerClassMap = new HashMap<Class<?>, ContentHandler>();
+		contentHandlerClassMap = new HashMap<Class<?>, ContentHandler<?>>();
-		contentHandlerTypeMap = new HashMap<String, ContentHandler>();
+		contentHandlerTypeMap = new HashMap<String, ContentHandler<?>>();
 
+		@SuppressWarnings("rawtypes")
 		List<ContentHandler> handlers = ClassSearcher.getInstances(ContentHandler.class);
-		for (ContentHandler ch : handlers) {
+		for (ContentHandler<?> ch : handlers) {
-			String type = ch.getContentType();
+			contentHandlerTypeMap.put(ch.getContentType(), ch);
-			Class<?> DOClass = ch.getDomainObjectClass();
+			if (!(ch instanceof LinkHandler<?>)) {
-			if (type != null && DOClass != null) {
+				contentHandlerClassMap.put(ch.getDomainObjectClass(), ch);
-				contentHandlerClassMap.put(DOClass, ch);
-				contentHandlerTypeMap.put(type, ch);
-				continue;
 			}
 		}
 		setDefaultContentClass(defaultDomainObjClass);

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/FolderLinkContentHandler.java

@@ -0,0 +1,119 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.IOException;
+import java.net.URL;
+
+import javax.swing.Icon;
+
+import ghidra.framework.main.AppInfo;
+import ghidra.framework.model.*;
+import ghidra.framework.store.FileSystem;
+import ghidra.util.InvalidNameException;
+import ghidra.util.exception.CancelledException;
+import ghidra.util.task.TaskMonitor;
+
+/**
+ * {@code FolderLinkContentHandler} provide folder-link support.  
+ * Implementation relies on {@link AppInfo#getActiveProject()} to provide life-cycle 
+ * management for related transient-projects opened while following folder-links. 
+ */
+public class FolderLinkContentHandler extends LinkHandler<NullFolderDomainObject> {
+
+	public static FolderLinkContentHandler INSTANCE = new FolderLinkContentHandler();
+
+	public static final String FOLDER_LINK_CONTENT_TYPE = "FolderLink";
+
+	@Override
+	public long createFile(FileSystem fs, FileSystem userfs, String path, String name,
+			DomainObject obj, TaskMonitor monitor)
+			throws IOException, InvalidNameException, CancelledException {
+		if (!(obj instanceof URLLinkObject)) {
+			throw new IOException("Unsupported domain object: " + obj.getClass().getName());
+		}
+		return createFile((URLLinkObject) obj, FOLDER_LINK_CONTENT_TYPE, fs, path, name,
+			monitor);
+	}
+
+	@Override
+	public String getContentType() {
+		return FOLDER_LINK_CONTENT_TYPE;
+	}
+
+	@Override
+	public String getContentTypeDisplayString() {
+		return FOLDER_LINK_CONTENT_TYPE;
+	}
+
+	@Override
+	public Class<NullFolderDomainObject> getDomainObjectClass() {
+		return NullFolderDomainObject.class; // special case since link corresponds to a Domain Folder
+	}
+
+	@Override
+	public Icon getIcon() {
+		return DomainFolder.CLOSED_FOLDER_ICON;
+	}
+
+	@Override
+	public String getDefaultToolName() {
+		return null;
+	}
+
+	/**
+	 * Get linked domain folder
+	 * @param folderLinkFile folder-link file.
+	 * @return {@link LinkedGhidraFolder} referenced by specified folder-link file or null if 
+	 * folderLinkFile content type is not {@value #FOLDER_LINK_CONTENT_TYPE}.
+	 * @throws IOException if an IO or folder item access error occurs
+	 */
+	public static LinkedGhidraFolder getReadOnlyLinkedFolder(DomainFile folderLinkFile)
+			throws IOException {
+
+		if (!FOLDER_LINK_CONTENT_TYPE.equals(folderLinkFile.getContentType())) {
+			return null;
+		}
+
+		URL url = getURL(folderLinkFile);
+
+		Project activeProject = AppInfo.getActiveProject();
+		GhidraFolder parent = ((GhidraFile) folderLinkFile).getParent();
+		return new LinkedGhidraFolder(activeProject, parent, folderLinkFile.getName(), url);
+	}
+
+}
+
+/**
+ * Dummy domain object to satisfy {@link FolderLinkContentHandler#getDomainObjectClass()}
+ */
+final class NullFolderDomainObject extends DomainObjectAdapterDB {
+	private NullFolderDomainObject() {
+		// this object may not be instantiated
+		super(null, null, 0, NullFolderDomainObject.class);
+		throw new RuntimeException("Object may not be instantiated");
+	}
+
+	@Override
+	public boolean isChangeable() {
+		return false;
+	}
+
+	@Override
+	public String getDescription() {
+		return "Dummy FolderLink Domain Object";
+	}
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFile.java

@@ -16,6 +16,7 @@
 package ghidra.framework.data;
 
 import java.io.*;
+import java.net.URL;
 import java.util.*;
 
 import javax.swing.Icon;
@@ -24,8 +25,7 @@ import ghidra.framework.model.*;
 import ghidra.framework.store.ItemCheckoutStatus;
 import ghidra.framework.store.Version;
 import ghidra.framework.store.local.LocalFileSystem;
-import ghidra.util.InvalidNameException;
+import ghidra.util.*;
-import ghidra.util.ReadOnlyException;
 import ghidra.util.exception.*;
 import ghidra.util.task.TaskMonitor;
 
@@ -123,6 +123,17 @@ public class GhidraFile implements DomainFile {
 		return fileManager.getProjectLocator();
 	}
 
+	@Override
+	public URL getSharedProjectURL() {
+		try {
+			return getFileData().getSharedProjectURL();
+		}
+		catch (IOException e) {
+			// ignore
+		}
+		return null;
+	}
+
 	@Override
 	public String getContentType() {
 		try {
@@ -134,6 +145,37 @@ public class GhidraFile implements DomainFile {
 		return ContentHandler.UNKNOWN_CONTENT;
 	}
 
+	@Override
+	public boolean isLinkFile() {
+		try {
+			return getFileData().isLinkFile();
+		}
+		catch (IOException e) {
+			return false;
+		}
+	}
+
+	@Override
+	public DomainFolder followLink() {
+		try {
+			return FolderLinkContentHandler.getReadOnlyLinkedFolder(this);
+		}
+		catch (IOException e) {
+			Msg.error(this, "Failed to following folder-link: " + getPathname());
+		}
+		return null;
+	}
+
+	@Override
+	public boolean isLinkingSupported() {
+		try {
+			return getFileData().isLinkingSupported();
+		}
+		catch (IOException e) {
+			return false;
+		}
+	}
+
 	@Override
 	public Class<? extends DomainObject> getDomainObjectClass() {
 		try {
@@ -146,7 +188,7 @@ public class GhidraFile implements DomainFile {
 	}
 
 	@Override
-	public DomainFolder getParent() {
+	public GhidraFolder getParent() {
 		return parent;
 	}
 
@@ -257,7 +299,7 @@ public class GhidraFile implements DomainFile {
 		catch (IOException e) {
 			fileError(e);
 		}
-		return GhidraFileData.UNSUPPORTED_FILE_ICON;
+		return UNSUPPORTED_FILE_ICON;
 	}
 
 	@Override
@@ -353,17 +395,6 @@ public class GhidraFile implements DomainFile {
 		return true;
 	}
 
-	@Override
-	public boolean isVersionControlSupported() {
-		try {
-			return getFileData().isVersionControlSupported();
-		}
-		catch (IOException e) {
-			fileError(e);
-		}
-		return false;
-	}
-
 	@Override
 	public boolean isVersioned() {
 		try {
@@ -482,6 +513,9 @@ public class GhidraFile implements DomainFile {
 
 	@Override
 	public GhidraFile moveTo(DomainFolder newParent) throws IOException {
+		if (!GhidraFolder.class.isAssignableFrom(newParent.getClass())) {
+			throw new UnsupportedOperationException("newParent does not support moveTo");
+		}
 		GhidraFolder newGhidraParent = (GhidraFolder) newParent;
 		return getFileData().moveTo(newGhidraParent.getFolderData());
 	}
@@ -489,15 +523,30 @@ public class GhidraFile implements DomainFile {
 	@Override
 	public DomainFile copyTo(DomainFolder newParent, TaskMonitor monitor) throws IOException,
 			CancelledException {
-		GhidraFolder newGhidraParent = (GhidraFolder) newParent; // assumes single implementation
+		if (!GhidraFolder.class.isAssignableFrom(newParent.getClass())) {
+			throw new UnsupportedOperationException("newParent does not support copyTo");
+		}
+		GhidraFolder newGhidraParent = (GhidraFolder) newParent;
 		return getFileData().copyTo(newGhidraParent.getFolderData(),
 			monitor != null ? monitor : TaskMonitor.DUMMY);
 	}
 
+	@Override
+	public DomainFile copyToAsLink(DomainFolder newParent) throws IOException {
+		if (!GhidraFolder.class.isAssignableFrom(newParent.getClass())) {
+			throw new UnsupportedOperationException("newParent does not support copyToAsLink");
+		}
+		GhidraFolder newGhidraParent = (GhidraFolder) newParent;
+		return getFileData().copyToAsLink(newGhidraParent.getFolderData());
+	}
+
 	@Override
 	public DomainFile copyVersionTo(int version, DomainFolder destFolder, TaskMonitor monitor)
 			throws IOException, CancelledException {
-		GhidraFolder destGhidraFolder = (GhidraFolder) destFolder; // assumes single implementation
+		if (!GhidraFolder.class.isAssignableFrom(destFolder.getClass())) {
+			throw new UnsupportedOperationException("destFolder does not support copyVersionTo");
+		}
+		GhidraFolder destGhidraFolder = (GhidraFolder) destFolder;
 		return getFileData().copyVersionTo(version, destGhidraFolder.getFolderData(),
 			monitor != null ? monitor : TaskMonitor.DUMMY);
 	}
@@ -507,7 +556,7 @@ public class GhidraFile implements DomainFile {
 	 * only when a non shared project is being converted to a shared project.
 	 * @param monitor task monitor
 	 * @throws IOException if an IO error occurs
-	 * @throws CancelledException if task cancelled
+	 * @throws CancelledException if task is cancelled
 	 */
 	void convertToPrivateFile(TaskMonitor monitor) throws IOException, CancelledException {
 		getFileData().convertToPrivateFile(
@@ -596,6 +645,10 @@ public class GhidraFile implements DomainFile {
 
 	@Override
 	public String toString() {
+		ProjectLocator projectLocator = parent.getProjectData().getProjectLocator();
+		if (projectLocator.isTransient()) {
+			return fileManager.getProjectLocator().getName() + getPathname();
+		}
 		return fileManager.getProjectLocator().getName() + ":" + getPathname();
 	}
 

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFileData.java

@@ -17,6 +17,8 @@ package ghidra.framework.data;
 
 import java.awt.*;
 import java.io.*;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -27,9 +29,9 @@ import db.Field;
 import db.buffers.*;
 import generic.theme.GColor;
 import generic.theme.GIcon;
-import ghidra.framework.client.ClientUtil;
+import ghidra.framework.client.*;
-import ghidra.framework.client.NotConnectedException;
 import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
 import ghidra.framework.store.*;
 import ghidra.framework.store.FileSystem;
 import ghidra.framework.store.local.LocalFileSystem;
@@ -37,12 +39,14 @@ import ghidra.framework.store.local.LocalFolderItem;
 import ghidra.util.*;
 import ghidra.util.exception.*;
 import ghidra.util.task.TaskMonitor;
-import ghidra.util.task.TaskMonitorAdapter;
 import resources.MultiIcon;
 import resources.icons.TranslateIcon;
 
 public class GhidraFileData {
 
+	static final int ICON_WIDTH = 18;
+	static final int ICON_HEIGHT = 17;
+
 	private static final boolean ALWAYS_MERGE = System.getProperty("ForceMerge") != null;
 
 	//@formatter:off
@@ -50,6 +54,7 @@ public class GhidraFileData {
 	public static final Icon CHECKED_OUT_ICON = new GIcon("icon.project.data.file.ghidra.checked.out");
 	public static final Icon CHECKED_OUT_EXCLUSIVE_ICON = new GIcon("icon.project.data.file.ghidra.checked.out.exclusive");
 	public static final Icon HIJACKED_ICON = new GIcon("icon.project.data.file.ghidra.hijacked");
+
 	public static final Icon VERSION_ICON = new VersionIcon();
 	public static final Icon READ_ONLY_ICON = new GIcon("icon.project.data.file.ghidra.read.only");
 	public static final Icon NOT_LATEST_CHECKED_OUT_ICON = new GIcon("icon.project.data.file.ghidra.not.latest");
@@ -202,9 +207,32 @@ public class GhidraFileData {
 		return new GhidraFile(parent.getDomainFolder(), name);
 	}
 
+	/**
+	 * Get a remote Ghidra URL for this domain file if available within a remote repository.
+	 * @return remote Ghidra URL for this file or null
+	 */
+	URL getSharedProjectURL() {
+		synchronized (fileSystem) {
+			RepositoryAdapter repository = parent.getProjectFileManager().getRepository();
+			if (versionedFolderItem != null && repository != null) {
+				URL folderURL = parent.getDomainFolder().getSharedProjectURL();
+				try {
+					// Direct URL construction done so that ghidra protocol 
+					// extension may be supported
+					return new URL(folderURL.toExternalForm() + name);
+				}
+				catch (MalformedURLException e) {
+					// ignore
+				}
+			}
+			return null;
+		}
+	}
+
 	/**
 	 * Reassign a new file-ID to resolve file-ID conflict.
 	 * Conflicts can occur as a result of a cancelled check-out.
+	 * @throws IOException if an IO error occurs
 	 */
 	void resetFileID() throws IOException {
 		synchronized (fileSystem) {
@@ -262,6 +290,8 @@ public class GhidraFileData {
 	String getContentType() {
 		synchronized (fileSystem) {
 			FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
+			// this can happen when we are trying to load a version file from
+			// a server to which we are not connected
 			if (item == null) {
 				return ContentHandler.MISSING_CONTENT;
 			}
@@ -270,14 +300,27 @@ public class GhidraFileData {
 		}
 	}
 
-	Class<? extends DomainObject> getDomainObjectClass() {
+	/**
+	 * Get content handler
+	 * @return content handler
+	 * @throws IOException if an IO error occurs, file not found, or unsupported content
+	 */
+	ContentHandler<?> getContentHandler() throws IOException {
 		synchronized (fileSystem) {
 			FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
-			try {
+			// this can happen when we are trying to load a version file from
-				ContentHandler ch = DomainObjectAdapter.getContentHandler(item.getContentType());
+			// a server to which we are not connected
-				if (ch != null) {
+			if (item == null) {
-					return ch.getDomainObjectClass();
+				throw new FileNotFoundException(name + " not found");
 			}
+			return DomainObjectAdapter.getContentHandler(item.getContentType());
+		}
+	}
+
+	Class<? extends DomainObject> getDomainObjectClass() {
+		synchronized (fileSystem) {
+			try {
+				return getContentHandler().getDomainObjectClass();
 			}
 			catch (IOException e) {
 				// ignore missing content handler
@@ -289,8 +332,7 @@ public class GhidraFileData {
 	ChangeSet getChangesByOthersSinceCheckout() throws VersionException, IOException {
 		synchronized (fileSystem) {
 			if (versionedFolderItem != null && folderItem != null && folderItem.isCheckedOut()) {
-				ContentHandler ch =
+				ContentHandler<?> ch = getContentHandler();
-					DomainObjectAdapter.getContentHandler(folderItem.getContentType());
 				return ch.getChangeSet(versionedFolderItem, folderItem.getCheckoutVersion(),
 					versionedFolderItem.getCurrentVersion());
 			}
@@ -305,10 +347,9 @@ public class GhidraFileData {
 	DomainObject getDomainObject(Object consumer, boolean okToUpgrade, boolean okToRecover,
 			TaskMonitor monitor) throws VersionException, IOException, CancelledException {
 		FolderItem myFolderItem;
-		ContentHandler ch;
 		DomainObjectAdapter domainObj = null;
 		synchronized (fileSystem) {
-			if (fileSystem.isReadOnly()) {
+			if (fileSystem.isReadOnly() || isLinkFile()) {
 				return getReadOnlyDomainObject(consumer, DomainFile.DEFAULT_VERSION, monitor);
 			}
 			domainObj = getOpenedDomainObject();
@@ -321,8 +362,8 @@ public class GhidraFileData {
 					return domainObj;
 				}
 			}
+			ContentHandler<?> ch = getContentHandler();
 			if (folderItem == null) {
-				ch = DomainObjectAdapter.getContentHandler(versionedFolderItem.getContentType());
 				DomainObjectAdapter doa = ch.getReadOnlyObject(versionedFolderItem,
 					DomainFile.DEFAULT_VERSION, true, consumer, monitor);
 				doa.setChanged(false);
@@ -331,7 +372,6 @@ public class GhidraFileData {
 				proxy.setLastModified(getLastModifiedTime());
 				return doa;
 			}
-			ch = DomainObjectAdapter.getContentHandler(folderItem.getContentType());
 			myFolderItem = folderItem;
 
 			domainObj = ch.getDomainObject(myFolderItem, parent.getUserFileSystem(),
@@ -368,14 +408,7 @@ public class GhidraFileData {
 			FolderItem item =
 				(folderItem != null && version == DomainFile.DEFAULT_VERSION) ? folderItem
 						: versionedFolderItem;
-
+			ContentHandler<?> ch = getContentHandler();
-			// this can happen when we are trying to load a version file from
-			// a server to which we are not connected
-			if (item == null) {
-				return null;
-			}
-
-			ContentHandler ch = DomainObjectAdapter.getContentHandler(item.getContentType());
 			DomainObjectAdapter doa = ch.getReadOnlyObject(item, version, true, consumer, monitor);
 			doa.setChanged(false);
 
@@ -390,15 +423,12 @@ public class GhidraFileData {
 			throws VersionException, IOException, CancelledException {
 		synchronized (fileSystem) {
 			DomainObjectAdapter obj = null;
+			ContentHandler<?> ch = getContentHandler();
 			if (versionedFolderItem == null ||
 				(version == DomainFile.DEFAULT_VERSION && folderItem != null) || isHijacked()) {
-				ContentHandler ch =
-					DomainObjectAdapter.getContentHandler(folderItem.getContentType());
 				obj = ch.getImmutableObject(folderItem, consumer, version, -1, monitor);
 			}
 			else {
-				ContentHandler ch =
-					DomainObjectAdapter.getContentHandler(versionedFolderItem.getContentType());
 				obj = ch.getImmutableObject(versionedFolderItem, consumer, version, -1, monitor);
 			}
 			DomainFileProxy proxy = new DomainFileProxy(name, getParent().getPathname(), obj,
@@ -419,8 +449,11 @@ public class GhidraFileData {
 	}
 
 	boolean takeRecoverySnapshot() throws IOException {
+		if (fileSystem.isReadOnly()) {
+			return true;
+		}
 		DomainObjectAdapter dobj = fileManager.getOpenedDomainObject(getPathname());
-		if (fileSystem.isReadOnly() || !(dobj instanceof DomainObjectAdapterDB) ||
+		if (!(dobj instanceof DomainObjectAdapterDB) ||
 			!dobj.isChanged()) {
 			return true;
 		}
@@ -481,13 +514,19 @@ public class GhidraFileData {
 	private Icon generateIcon(boolean disabled) {
 		if (parent == null) {
 			// instance has been disposed
-			return UNSUPPORTED_FILE_ICON;
+			return DomainFile.UNSUPPORTED_FILE_ICON;
 		}
 		synchronized (fileSystem) {
+
+			boolean isLink = isLinkFile();
+
 			FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
+
+			Icon baseIcon = new TranslateIcon(getBaseIcon(item), 1, 1);
+
 			if (versionedFolderItem != null) {
 				MultiIcon multiIcon = new MultiIcon(VERSION_ICON, disabled);
-				multiIcon.addIcon(getBaseIcon(item));
+				multiIcon.addIcon(baseIcon);
 				if (isHijacked()) {
 					multiIcon.addIcon(HIJACKED_ICON);
 				}
@@ -504,12 +543,15 @@ public class GhidraFileData {
 						}
 					}
 				}
+				if (isLink) {
+					multiIcon.addIcon(new TranslateIcon(LinkHandler.LINK_ICON, 0, 1));
+				}
 				return multiIcon;
 			}
 			else if (folderItem != null) {
-				MultiIcon multiIcon = new MultiIcon(getBaseIcon(item), disabled);
+				MultiIcon multiIcon = new MultiIcon(baseIcon, disabled, ICON_WIDTH, ICON_HEIGHT);
 				if (isReadOnly() && !fileSystem.isReadOnly()) {
-					multiIcon.addIcon(new TranslateIcon(READ_ONLY_ICON, 6, 6));
+					multiIcon.addIcon(new TranslateIcon(READ_ONLY_ICON, 8, 9));
 				}
 				if (isCheckedOut()) {
 					if (isCheckedOutExclusive()) {
@@ -519,23 +561,23 @@ public class GhidraFileData {
 						multiIcon.addIcon(CHECKED_OUT_ICON);
 					}
 				}
+				if (isLink) {
+					multiIcon.addIcon(new TranslateIcon(LinkHandler.LINK_ICON, 0, 1));
+				}
 				return multiIcon;
 			}
 		}
-		return UNSUPPORTED_FILE_ICON;
+		return DomainFile.UNSUPPORTED_FILE_ICON;
 	}
 
 	private Icon getBaseIcon(FolderItem item) {
 		try {
-			ContentHandler ch = DomainObjectAdapter.getContentHandler(item.getContentType());
+			return getContentHandler().getIcon();
-			if (ch != null) {
-				return ch.getIcon();
-			}
 		}
 		catch (IOException e) {
 			// ignore missing content handler
 		}
-		return UNSUPPORTED_FILE_ICON;
+		return DomainFile.UNSUPPORTED_FILE_ICON;
 	}
 
 	boolean isChanged() {
@@ -593,9 +635,19 @@ public class GhidraFileData {
 	boolean canAddToRepository() {
 		synchronized (fileSystem) {
 			try {
-				return (!fileSystem.isReadOnly() && !versionedFileSystem.isReadOnly() &&
+				if (fileSystem.isReadOnly() || versionedFileSystem.isReadOnly()) {
-					folderItem != null && versionedFolderItem == null &&
+					return false;
-					!folderItem.isCheckedOut() && isVersionControlSupported());
+				}
+				if (folderItem == null || versionedFolderItem != null) {
+					return false;
+				}
+				if (folderItem.isCheckedOut()) {
+					return false;
+				}
+				if (isLinkFile()) {
+					return GhidraURL.isServerRepositoryURL(LinkHandler.getURL(folderItem));
+				}
+				return !getContentHandler().isPrivateContentType();
 			}
 			catch (IOException e) {
 				return false;
@@ -606,8 +658,11 @@ public class GhidraFileData {
 	boolean canCheckout() {
 		synchronized (fileSystem) {
 			try {
-				return folderItem == null && !fileSystem.isReadOnly() &&
+				if (folderItem != null || fileSystem.isReadOnly() ||
-					!versionedFileSystem.isReadOnly();
+					versionedFileSystem.isReadOnly()) {
+					return false;
+				}
+				return !isLinkFile();
 			}
 			catch (IOException e) {
 				return false;
@@ -627,26 +682,6 @@ public class GhidraFileData {
 		}
 	}
 
-	boolean isVersionControlSupported() {
-		synchronized (fileSystem) {
-			if (versionedFolderItem != null) {
-				return true;
-			}
-			if (!(folderItem instanceof DatabaseItem)) {
-				return false;
-			}
-			try {
-				ContentHandler ch =
-					DomainObjectAdapter.getContentHandler(folderItem.getContentType());
-				return !ch.isPrivateContentType();
-			}
-			catch (IOException e) {
-				// ignore missing content handler
-			}
-			return false;
-		}
-	}
-
 	int getVersion() {
 		synchronized (fileSystem) {
 			try {
@@ -714,19 +749,16 @@ public class GhidraFileData {
 			throws IOException, CancelledException {
 		DomainObjectAdapter oldDomainObj = null;
 		synchronized (fileSystem) {
-			if (!isVersionControlSupported()) {
+			if (!canAddToRepository()) {
-				throw new AssertException("file type does supported version control");
-			}
-			if (versionedFolderItem != null) {
-				throw new AssertException("file already versioned");
-			}
-			if (!versionedFileSystem.isOnline()) {
-				throw new NotConnectedException("Not connected to repository server");
-			}
 				if (fileSystem.isReadOnly() || versionedFileSystem.isReadOnly()) {
 					throw new ReadOnlyException(
 						"addToVersionControl permitted within writeable project and repository only");
 				}
+				throw new IOException("addToVersionControl not allowed for file");
+			}
+			if (isLinkFile()) {
+				keepCheckedOut = false;
+			}
 			String parentPath = parent.getPathname();
 			String user = ClientUtil.getUserName();
 			try {
@@ -832,6 +864,9 @@ public class GhidraFileData {
 			if (!versionedFileSystem.isOnline()) {
 				throw new NotConnectedException("Not connected to repository server");
 			}
+			if (isLinkFile()) {
+				return false;
+			}
 			String user = ClientUtil.getUserName();
 			ProjectLocator projectLocator = parent.getProjectLocator();
 			CheckoutType checkoutType;
@@ -934,8 +969,7 @@ public class GhidraFileData {
 			if (checkinHandler.createKeepFile()) {
 				DomainObject sourceObj = null;
 				try {
-					ContentHandler ch =
+					ContentHandler<?> ch = getContentHandler();
-						DomainObjectAdapter.getContentHandler(folderItem.getContentType());
 					sourceObj = ch.getImmutableObject(folderItem, this, DomainFile.DEFAULT_VERSION,
 						-1, monitor);
 					createKeepFile(sourceObj, monitor);
@@ -968,18 +1002,18 @@ public class GhidraFileData {
 
 	/**
 	 * Verify that current user is the checkout user for this file
-	 * @param caseName name of user case (e.g., checkin)
+	 * @param operationName name of user case (e.g., checkin)
-	 * @return true if server/repository will permit current user to checkin,
+	 * @throws IOException if server/repository will not permit current user to checkin,
-	 * or update checkout version of current file.  (i.e., server login matches
+	 * or update checkout version of current file.  (i.e., server login does not match
 	 * user name used at time of initial checkout)
 	 */
-	private void verifyRepoUser(String caseName) throws IOException {
+	private void verifyRepoUser(String operationName) throws IOException {
 		if (versionedFileSystem instanceof LocalFileSystem) {
 			return; // rely on local project ownership
 		}
 		String repoUserName = versionedFileSystem.getUserName();
 		if (repoUserName == null) {
-			throw new IOException("File " + caseName + " not permitted (not connected)");
+			throw new IOException("File " + operationName + " not permitted (not connected)");
 		}
 		ItemCheckoutStatus checkoutStatus = getCheckoutStatus();
 		if (checkoutStatus == null) {
@@ -987,7 +1021,7 @@ public class GhidraFileData {
 		}
 		String checkoutUserName = checkoutStatus.getUser();
 		if (!repoUserName.equals(checkoutUserName)) {
-			throw new IOException("File " + caseName + " not permitted - checkout user '" +
+			throw new IOException("File " + operationName + " not permitted - checkout user '" +
 				checkoutUserName + "' differs from repository user '" + repoUserName + "'");
 		}
 	}
@@ -1016,7 +1050,7 @@ public class GhidraFileData {
 		}
 		verifyRepoUser("checkin");
 		if (monitor == null) {
-			monitor = TaskMonitorAdapter.DUMMY_MONITOR;
+			monitor = TaskMonitor.DUMMY;
 		}
 		synchronized (fileSystem) {
 			if (busy) {
@@ -1036,9 +1070,7 @@ public class GhidraFileData {
 
 				Msg.info(this, "Checkin with merge for " + name);
 
-				ContentHandler ch =
+				ContentHandler<?> ch = getContentHandler();
-					DomainObjectAdapter.getContentHandler(folderItem.getContentType());
-
 				DomainObjectAdapter checkinObj = ch.getDomainObject(versionedFolderItem, null,
 					folderItem.getCheckoutId(), okToUpgrade, false, this, monitor);
 				checkinObj.setDomainFile(new DomainFileProxy(name, getParent().getPathname(),
@@ -1366,9 +1398,12 @@ public class GhidraFileData {
 
 	private void removeAssociatedUserDataFile() {
 		try {
+			ContentHandler<?> ch = getContentHandler();
+			if (ch instanceof DBWithUserDataContentHandler) {
 				FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
-			ContentHandler ch = DomainObjectAdapter.getContentHandler(item.getContentType());
+				((DBWithUserDataContentHandler<?>) ch).removeUserDataFile(item,
-			ch.removeUserDataFile(item, parent.getUserFileSystem());
+					parent.getUserFileSystem());
+			}
 		}
 		catch (Exception e) {
 			// ignore missing content handler
@@ -1403,7 +1438,7 @@ public class GhidraFileData {
 		}
 		verifyRepoUser("merge");
 		if (monitor == null) {
-			monitor = TaskMonitorAdapter.DUMMY_MONITOR;
+			monitor = TaskMonitor.DUMMY;
 		}
 		synchronized (fileSystem) {
 			if (busy) {
@@ -1425,8 +1460,7 @@ public class GhidraFileData {
 						"Merge failed, file merge is not supported in headless mode");
 				}
 
-				ContentHandler ch =
+				ContentHandler<?> ch = getContentHandler();
-					DomainObjectAdapter.getContentHandler(folderItem.getContentType());
 
 				// Test versioned file for VersionException
 				int mergeVer = versionedFolderItem.getCurrentVersion();
@@ -1556,7 +1590,7 @@ public class GhidraFileData {
 			checkInUse();
 			GhidraFolderData oldParent = parent;
 			String oldName = name;
-			String newName = getTargetName(name, newParent);
+			String newName = newParent.getTargetName(name);
 			try {
 				if (isHijacked()) {
 					fileSystem.moveItem(parent.getPathname(), name, newParent.getPathname(),
@@ -1595,15 +1629,49 @@ public class GhidraFileData {
 		}
 	}
 
-	private String getTargetName(String preferredName, GhidraFolderData newParent)
+	boolean isLinkFile() {
-			throws IOException {
+		synchronized (fileSystem) {
-		String newName = preferredName;
+			try {
-		int i = 1;
+				return LinkHandler.class.isAssignableFrom(getContentHandler().getClass());
-		while (newParent.getFileData(newName, false) != null) {
+			}
-			newName = preferredName + "." + i;
+			catch (IOException e) {
-			i++;
+				return false;
+			}
+		}
+	}
+
+	/**
+	 * Get URL associated with a link-file
+	 * @return link-file URL or null if not a link-file
+	 * @throws IOException if an IO error occurs
+	 */
+	URL getLinkFileURL() throws IOException {
+		if (!isLinkFile()) {
+			return null;
+		}
+		FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
+		return LinkHandler.getURL(item);
+	}
+
+	public boolean isLinkingSupported() {
+		synchronized (fileSystem) {
+			try {
+				return getContentHandler().getLinkHandler() != null;
+			}
+			catch (IOException e) {
+				return false; // ignore error
+			}
+		}
+	}
+
+	public DomainFile copyToAsLink(GhidraFolderData newParentData) throws IOException {
+		synchronized (fileSystem) {
+			LinkHandler<?> lh = getContentHandler().getLinkHandler();
+			if (lh == null) {
+				return null;
+			}
+			return newParentData.copyAsLink(fileManager, getPathname(), name, lh);
 		}
-		return newName;
 	}
 
 	GhidraFile copyTo(GhidraFolderData newParentData, TaskMonitor monitor)
@@ -1615,7 +1683,7 @@ public class GhidraFileData {
 			FolderItem item = folderItem != null ? folderItem : versionedFolderItem;
 			String pathname = newParentData.getPathname();
 			String contentType = item.getContentType();
-			String targetName = getTargetName(name, newParentData);
+			String targetName = newParentData.getTargetName(name);
 			String user = ClientUtil.getUserName();
 			try {
 				if (item instanceof DatabaseItem) {
@@ -1668,7 +1736,7 @@ public class GhidraFileData {
 			}
 			String pathname = destFolderData.getPathname();
 			String contentType = versionedFolderItem.getContentType();
-			String targetName = getTargetName(name + "_v" + version, destFolderData);
+			String targetName = destFolderData.getTargetName(name + "_v" + version);
 			String user = ClientUtil.getUserName();
 			try {
 				BufferFile bufferFile = ((DatabaseItem) versionedFolderItem).open(version);
@@ -1697,7 +1765,9 @@ public class GhidraFileData {
 	/**
 	 * Copy this file to make a private file if it is versioned. This method should be called
 	 * only when a non shared project is being converted to a shared project.
-	 * @throws IOException
+	 * @param monitor task monitor
+	 * @throws IOException if an IO error occurs
+	 * @throws CancelledException if task is cancelled
 	 */
 	void convertToPrivateFile(TaskMonitor monitor) throws IOException, CancelledException {
 		synchronized (fileSystem) {
@@ -1749,7 +1819,10 @@ public class GhidraFileData {
 
 	Map<String, String> getMetadata() {
 		FolderItem item = (folderItem != null) ? folderItem : versionedFolderItem;
+		return getMetadata(item);
+	}
 
+	static Map<String, String> getMetadata(FolderItem item) {
 		GenericDomainObjectDB genericDomainObj = null;
 		try {
 			if (item instanceof DatabaseItem) {
@@ -1767,7 +1840,7 @@ public class GhidraFileData {
 			// file created with newer version of Ghidra
 		}
 		catch (IOException e) {
-			Msg.error(this, "Read meta-data error", e);
+			Msg.error(GhidraFileData.class, "Read meta-data error", e);
 		}
 		finally {
 			if (genericDomainObj != null) {
@@ -1782,13 +1855,17 @@ public class GhidraFileData {
 		if (fileManager == null) {
 			return name + "(disposed)";
 		}
+		ProjectLocator projectLocator = fileManager.getProjectLocator();
+		if (projectLocator.isTransient()) {
+			return fileManager.getProjectLocator().getName() + getPathname();
+		}
 		return fileManager.getProjectLocator().getName() + ":" + getPathname();
 	}
 
-	private class GenericDomainObjectDB extends DomainObjectAdapterDB {
+	private static class GenericDomainObjectDB extends DomainObjectAdapterDB {
 
 		protected GenericDomainObjectDB(DBHandle dbh) throws IOException {
-			super(dbh, "Generic", 500, GhidraFileData.this);
+			super(dbh, "Generic", 500, dbh);
 			loadMetadata();
 		}
 
@@ -1803,7 +1880,7 @@ public class GhidraFileData {
 		}
 
 		public void release() {
-			release(GhidraFileData.this);
+			release(dbh);
 		}
 	}
 
@@ -1816,8 +1893,8 @@ class VersionIcon implements Icon {
 	private static Color VERSION_ICON_COLOR_LIGHT =
 		new GColor("color.bg.ghidra.file.data.version.icon.light");
 
-	private static final int WIDTH = 18;
+	private static final int WIDTH = GhidraFileData.ICON_WIDTH;
-	private static final int HEIGHT = 17;
+	private static final int HEIGHT = GhidraFileData.ICON_HEIGHT;
 
 	@Override
 	public int getIconHeight() {

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFolder.java

@@ -16,16 +16,19 @@
 package ghidra.framework.data;
 
 import java.io.*;
+import java.net.MalformedURLException;
+import java.net.URL;
 import java.util.List;
 
+import ghidra.framework.client.RepositoryAdapter;
 import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
 import ghidra.framework.store.FileSystem;
 import ghidra.framework.store.local.LocalFileSystem;
 import ghidra.util.InvalidNameException;
 import ghidra.util.Msg;
 import ghidra.util.exception.CancelledException;
 import ghidra.util.task.TaskMonitor;
-import ghidra.util.task.TaskMonitorAdapter;
 
 public class GhidraFolder implements DomainFolder {
 
@@ -83,19 +86,6 @@ public class GhidraFolder implements DomainFolder {
 		return fileData;
 	}
 
-	GhidraFolderData getFolderPathData(String folderPath) throws FileNotFoundException {
-		GhidraFolderData parentData = (folderPath.startsWith(FileSystem.SEPARATOR))
-				? fileManager.getRootFolderData()
-				: getFolderData();
-		GhidraFolderData folderData = parentData.getFolderPathData(folderPath, false);
-		if (folderData == null) {
-			String path = (folderPath.startsWith(FileSystem.SEPARATOR)) ? folderPath
-					: getPathname(folderPath);
-			throw new FileNotFoundException("folder " + path + " not found");
-		}
-		return folderData;
-	}
-
 	GhidraFolderData getFolderData() throws FileNotFoundException {
 		if (parent == null) {
 			return fileManager.getRootFolderData();
@@ -140,10 +130,10 @@ public class GhidraFolder implements DomainFolder {
 
 	/**
 	 * Refresh folder data - used for testing only
-	 * @throws IOException
+	 * @throws IOException if an IO error occurs
 	 */
 	void refreshFolderData() throws IOException {
-		getFolderData().refresh(false, true, TaskMonitorAdapter.DUMMY_MONITOR);
+		getFolderData().refresh(false, true, TaskMonitor.DUMMY);
 	}
 
 	@Override
@@ -193,6 +183,40 @@ public class GhidraFolder implements DomainFolder {
 		return path;
 	}
 
+	@Override
+	public URL getSharedProjectURL() {
+		ProjectLocator projectLocator = getProjectLocator();
+		URL projectURL = projectLocator.getURL();
+		if (!GhidraURL.isServerRepositoryURL(projectURL)) {
+			RepositoryAdapter repository = fileManager.getRepository();
+			if (repository == null) {
+				return null;
+			}
+			// NOTE: only supports ghidra protocol without extension protocol.
+			// Assumes any extension protocol use would be reflected in projectLocator URL.
+			ServerInfo serverInfo = repository.getServerInfo();
+			projectURL = GhidraURL.makeURL(serverInfo.getServerName(), serverInfo.getPortNumber(),
+				repository.getName());
+		}
+		try {
+			// Direct URL construction done so that ghidra protocol 
+			// extension may be supported
+			String urlStr = projectURL.toExternalForm();
+			if (urlStr.endsWith(FileSystem.SEPARATOR)) {
+				urlStr = urlStr.substring(0, urlStr.length() - 1);
+			}
+			String path = getPathname();
+			if (!path.endsWith(FileSystem.SEPARATOR)) {
+				path += FileSystem.SEPARATOR;
+			}
+			urlStr += path;
+			return new URL(urlStr);
+		}
+		catch (MalformedURLException e) {
+			return null;
+		}
+	}
+
 	@Override
 	public boolean isInWritableProject() {
 		return !getProjectData().getLocalFileSystem().isReadOnly();
@@ -244,7 +268,9 @@ public class GhidraFolder implements DomainFolder {
 				return folderData.isEmpty();
 			}
 			catch (FileNotFoundException e) {
-				return false; // TODO: what should we return if folder not found
+				// TODO: what should we return if folder not found or error occurs?
+				// True is returned to allow this method to be used to avoid continued access.
+				return true;
 			}
 		}
 	}
@@ -295,14 +321,14 @@ public class GhidraFolder implements DomainFolder {
 	public DomainFile createFile(String fileName, DomainObject obj, TaskMonitor monitor)
 			throws InvalidNameException, IOException, CancelledException {
 		return createFolderData().createFile(fileName, obj,
-			monitor != null ? monitor : TaskMonitorAdapter.DUMMY_MONITOR);
+			monitor != null ? monitor : TaskMonitor.DUMMY);
 	}
 
 	@Override
 	public DomainFile createFile(String fileName, File packFile, TaskMonitor monitor)
 			throws InvalidNameException, IOException, CancelledException {
 		return createFolderData().createFile(fileName, packFile,
-			monitor != null ? monitor : TaskMonitorAdapter.DUMMY_MONITOR);
+			monitor != null ? monitor : TaskMonitor.DUMMY);
 	}
 
 	@Override
@@ -325,8 +351,11 @@ public class GhidraFolder implements DomainFolder {
 		if (parent == null) {
 			throw new UnsupportedOperationException("root folder may not be moved");
 		}
+		if (!GhidraFolder.class.isAssignableFrom(newParent.getClass())) {
+			throw new UnsupportedOperationException("newParent does not support moveTo");
+		}
 		GhidraFolderData folderData = getFolderData();
-		GhidraFolder newGhidraParent = (GhidraFolder) newParent; // assumes single implementation
+		GhidraFolder newGhidraParent = (GhidraFolder) newParent;
 		return folderData.moveTo(newGhidraParent.getFolderData());
 	}
 
@@ -334,9 +363,22 @@ public class GhidraFolder implements DomainFolder {
 	public GhidraFolder copyTo(DomainFolder newParent, TaskMonitor monitor)
 			throws IOException, CancelledException {
 		GhidraFolderData folderData = getFolderData();
-		GhidraFolder newGhidraParent = (GhidraFolder) newParent; // assumes single implementation
+		if (!GhidraFolder.class.isAssignableFrom(newParent.getClass())) {
+			throw new UnsupportedOperationException("newParent does not support copyTo");
+		}
+		GhidraFolder newGhidraParent = (GhidraFolder) newParent;
 		return folderData.copyTo(newGhidraParent.getFolderData(),
-			monitor != null ? monitor : TaskMonitorAdapter.DUMMY_MONITOR);
+			monitor != null ? monitor : TaskMonitor.DUMMY);
+	}
+
+	@Override
+	public DomainFile copyToAsLink(DomainFolder newParent) throws IOException {
+		GhidraFolderData folderData = getFolderData();
+		if (!GhidraFolder.class.isAssignableFrom(newParent.getClass())) {
+			throw new UnsupportedOperationException("newParent does not support copyToAsLink");
+		}
+		GhidraFolder newGhidraParent = (GhidraFolder) newParent;
+		return folderData.copyToAsLink(newGhidraParent.getFolderData());
 	}
 
 	/**

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/GhidraFolderData.java

@@ -16,10 +16,13 @@
 package ghidra.framework.data;
 
 import java.io.*;
+import java.net.URL;
 import java.util.*;
 
 import ghidra.framework.client.RepositoryAdapter;
 import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
+import ghidra.framework.protocol.ghidra.TransientProjectData;
 import ghidra.framework.store.FileSystem;
 import ghidra.framework.store.local.LocalFileSystem;
 import ghidra.util.*;
@@ -257,9 +260,10 @@ class GhidraFolderData {
 			return folderList.isEmpty() && fileList.isEmpty();
 		}
 		catch (IOException e) {
-			// ignore
+			// TODO: what should we return if folder not found or error occurs?
+			// True is returned to allow this method to be used to avoid continued access.
+			return true;
 		}
-		return false;
 	}
 
 	List<String> getFileNames() {
@@ -919,7 +923,7 @@ class GhidraFolderData {
 
 			DomainFile oldDf = doa.getDomainFile();
 			try {
-				ContentHandler ch = DomainObjectAdapter.getContentHandler(doa);
+				ContentHandler<?> ch = DomainObjectAdapter.getContentHandler(doa);
 				ch.createFile(fileSystem, null, getPathname(), fileName, obj, monitor);
 
 				if (oldDf != null) {
@@ -1140,6 +1144,88 @@ class GhidraFolderData {
 		}
 	}
 
+	DomainFile copyToAsLink(GhidraFolderData newParentData) throws IOException {
+		synchronized (fileSystem) {
+			String linkFilename = name;
+			if (linkFilename == null) {
+				if (fileManager instanceof TransientProjectData) {
+					linkFilename = fileManager.getRepository().getName();
+				}
+				else {
+					linkFilename = fileManager.getProjectLocator().getName();
+				}
+			}
+			return newParentData.copyAsLink(fileManager, getPathname(), linkFilename,
+				FolderLinkContentHandler.INSTANCE);
+		}
+	}
+
+	DomainFile copyAsLink(ProjectData sourceProjectData, String pathname, String linkFilename,
+			LinkHandler<?> lh) throws IOException {
+		synchronized (fileSystem) {
+			if (fileSystem.isReadOnly()) {
+				throw new ReadOnlyException("copyAsLink permitted to writeable project only");
+			}
+
+			if (sourceProjectData == fileManager) {
+				// internal linking not yet supported
+				Msg.error(this, "Internal file/folder links not yet supported");
+				return null;
+			}
+
+			URL ghidraUrl = null;
+			if (sourceProjectData instanceof TransientProjectData) {
+				RepositoryAdapter repository = sourceProjectData.getRepository();
+				ServerInfo serverInfo = repository.getServerInfo();
+				ghidraUrl =
+					GhidraURL.makeURL(serverInfo.getServerName(), serverInfo.getPortNumber(),
+						repository.getName(), pathname);
+			}
+			else {
+				ProjectLocator projectLocator = sourceProjectData.getProjectLocator();
+				if (projectLocator.equals(fileManager.getProjectLocator())) {
+					return null; // local internal linking not supported
+				}
+				ghidraUrl = GhidraURL.makeURL(projectLocator, pathname, null);
+			}
+
+			String newName = linkFilename;
+			int i = 1;
+			while (true) {
+				GhidraFileData fileData = getFileData(newName, false);
+				if (fileData != null) {
+					// return existing file if link URL matches
+					if (ghidraUrl.equals(fileData.getLinkFileURL())) {
+						return getDomainFile(newName);
+					}
+					newName = linkFilename + "." + i;
+					++i;
+				}
+				break;
+			}
+
+			try {
+				lh.createLink(ghidraUrl, fileSystem, getPathname(), newName);
+			}
+			catch (InvalidNameException e) {
+				throw new IOException(e); // unexpected
+			}
+
+			fileChanged(newName);
+			return getDomainFile(newName);
+		}
+	}
+
+	String getTargetName(String preferredName) throws IOException {
+		String newName = preferredName;
+		int i = 1;
+		while (getFileData(newName, false) != null) {
+			newName = preferredName + "." + i;
+			i++;
+		}
+		return newName;
+	}
+
 	/**
 	 * used for testing
 	 */
@@ -1156,6 +1242,10 @@ class GhidraFolderData {
 
 	@Override
 	public String toString() {
+		ProjectLocator projectLocator = fileManager.getProjectLocator();
+		if (projectLocator.isTransient()) {
+			return fileManager.getProjectLocator().getName() + getPathname();
+		}
 		return fileManager.getProjectLocator().getName() + ":" + getPathname();
 	}
 

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkHandler.java

@@ -0,0 +1,210 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.Map;
+
+import javax.help.UnsupportedOperationException;
+import javax.swing.Icon;
+
+import generic.theme.GIcon;
+import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.*;
+import ghidra.framework.protocol.ghidra.GhidraURLConnection.StatusCode;
+import ghidra.framework.store.FileSystem;
+import ghidra.framework.store.FolderItem;
+import ghidra.framework.store.local.LocalFileSystem;
+import ghidra.util.InvalidNameException;
+import ghidra.util.exception.*;
+import ghidra.util.task.TaskMonitor;
+
+/**
+ * NOTE:  ALL ContentHandler implementations MUST END IN "ContentHandler".  If not,
+ * the ClassSearcher will not find them.
+ * 
+ * <code>LinkHandler</code> defines an application interface for handling domain files which are
+ * shortcut links to another supported content type.
+ * 
+ * @param <T> {@link URLLinkObject} implementation class
+ */
+public abstract class LinkHandler<T extends DomainObjectAdapterDB> extends DBContentHandler<T> {
+	
+	// TODO: Need to improve by making this meta data on file instead of database content.
+	//       Metadata use would eliminate need for DB but we lack support for non-DB files.
+
+	public static final String URL_METADATA_KEY = "link.url";
+
+	// 16x16 link icon where link is placed in lower-left corner
+	public static final Icon LINK_ICON = new GIcon("icon.content.handler.link.overlay");
+
+	/**
+	 * Create a link file using the specified URL
+	 * @param ghidraUrl link URL (must be a Ghidra URL - see {@link GhidraURL}).
+	 * @param fs filesystem where link file should be created 
+	 * @param folderPath folder path which should contain link file
+	 * @param linkFilename link filename
+	 * @throws IOException if an IO error occurs
+	 * @throws InvalidNameException if invalid folderPath or linkFilename specified
+	 */
+	protected final void createLink(URL ghidraUrl, LocalFileSystem fs, String folderPath,
+			String linkFilename) throws IOException, InvalidNameException {
+		URLLinkObject link = new URLLinkObject(linkFilename, ghidraUrl, this);
+		try {
+			createFile(fs, null, folderPath, linkFilename, link, TaskMonitor.DUMMY);
+		}
+		catch (CancelledException e) {
+			throw new AssertException(e); // won't happen
+		}
+		finally {
+			link.release(this);
+		}
+	}
+
+	@SuppressWarnings("unchecked")
+	@Override
+	public final T getReadOnlyObject(FolderItem item, int version, boolean okToUpgrade,
+			Object consumer, TaskMonitor monitor)
+			throws IOException, VersionException, CancelledException {
+
+		if (!okToUpgrade) {
+			throw new IllegalArgumentException("okToUpgrade must be true");
+		}
+
+		URL url = getURL(item);
+		
+		Class<?> domainObjectClass = getDomainObjectClass();
+		if (domainObjectClass == null) {
+			throw new UnsupportedOperationException("");
+		}
+
+		GhidraURLWrappedContent wrappedContent = null;
+		Object content = null;
+		try {
+			GhidraURLConnection c = (GhidraURLConnection) url.openConnection();
+			Object obj = c.getContent(); // read-only access
+			if (c.getStatusCode() == StatusCode.UNAUTHORIZED) {
+				throw new IOException("Authorization failure");
+			}
+			if (!(obj instanceof GhidraURLWrappedContent)) {
+				throw new IOException("Unsupported linked content");
+			}
+			wrappedContent = (GhidraURLWrappedContent) obj;
+			content = wrappedContent.getContent(consumer);
+			if (!(content instanceof DomainFile)) {
+				throw new IOException("Unsupported linked content: " + content.getClass());
+			}
+			DomainFile linkedFile = (DomainFile) content;
+			if (!getDomainObjectClass().isAssignableFrom(linkedFile.getDomainObjectClass())) {
+				throw new BadLinkException(
+					"Excepted " + getDomainObjectClass() + " but linked to " +
+						linkedFile.getDomainObjectClass());
+			}
+			return (T) linkedFile.getReadOnlyDomainObject(consumer, version, monitor);
+		}
+		finally {
+			if (content != null) {
+				wrappedContent.release(content, consumer);
+			}
+		}
+	}
+
+	@Override
+	public final T getDomainObject(FolderItem item, FileSystem userfs, long checkoutId,
+			boolean okToUpgrade, boolean okToRecover, Object consumer, TaskMonitor monitor)
+			throws IOException, CancelledException, VersionException {
+		// Always upgrade if needed for read-only object
+		return getReadOnlyObject(item, DomainFile.DEFAULT_VERSION, true, consumer, monitor);
+	}
+
+	@Override
+	public T getImmutableObject(FolderItem item, Object consumer, int version, int minChangeVersion,
+			TaskMonitor monitor) throws IOException, CancelledException, VersionException {
+		throw new UnsupportedOperationException("link-file does not support getImmutableObject");
+	}
+
+	@Override
+	public final ChangeSet getChangeSet(FolderItem versionedFolderItem, int olderVersion,
+			int newerVersion) throws VersionException, IOException {
+		return null;
+	}
+
+	@Override
+	public final DomainObjectMergeManager getMergeManager(DomainObject resultsObj,
+			DomainObject sourceObj,
+			DomainObject originalObj, DomainObject latestObj) {
+		return null;
+	}
+
+	@Override
+	public final boolean isPrivateContentType() {
+		// NOTE: URL must be checked - only repository-based links may be versioned
+		return true;
+	}
+
+	/**
+	 * Get the link URL which corresponds to the specified link file.
+	 * See {@link DomainFile#isLinkFile()}.
+	 * @param linkFile link-file domain file
+	 * @return link URL
+	 * @throws MalformedURLException if link is bad or unsupported.
+	 * @throws IOException if IO error or supported link file not specified
+	 */
+	public static URL getURL(DomainFile linkFile) throws IOException {
+		String contentType = linkFile.getContentType();
+		ContentHandler<?> ch = DomainObjectAdapter.getContentHandler(contentType);
+		if (ch instanceof LinkHandler) {
+			Map<String, String> metadata = linkFile.getMetadata();
+			String urlStr = metadata.get(URL_METADATA_KEY);
+			if (urlStr != null) {
+				return new URL(urlStr);
+			}
+		}
+		throw new IOException("Invalid link file: " + contentType);
+	}
+
+	/**
+	 * Get the link URL which corresponds to the specified link file.
+	 * See {@link DomainFile#isLinkFile()}.
+	 * @param linkFile link-file folder item
+	 * @return link URL
+	 * @throws MalformedURLException if link is bad or unsupported.
+	 * @throws IOException if IO error or supported link file not specified
+	 */
+	static URL getURL(FolderItem linkFile) throws IOException {
+
+		String contentType = linkFile.getContentType();
+		ContentHandler<?> ch = DomainObjectAdapter.getContentHandler(contentType);
+		if (ch instanceof LinkHandler) {
+			Map<String, String> metadata = GhidraFileData.getMetadata(linkFile);
+			String urlStr = metadata.get(URL_METADATA_KEY);
+			if (urlStr != null) {
+				return new URL(urlStr);
+			}
+		}
+		throw new IOException("Invalid link file: " + contentType);
+	}
+
+	/**
+	 * Get the base icon for this link-file which does not include the 
+	 * link overlay icon.
+	 */
+	@Override
+	abstract public Icon getIcon();
+
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraFile.java

@@ -0,0 +1,426 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.List;
+import java.util.Map;
+
+import javax.help.UnsupportedOperationException;
+import javax.swing.Icon;
+
+import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
+import ghidra.framework.store.*;
+import ghidra.util.*;
+import ghidra.util.exception.CancelledException;
+import ghidra.util.exception.VersionException;
+import ghidra.util.task.TaskMonitor;
+
+/**
+ * {@code LinkedGhidraFile} corresponds to a {@link DomainFile} contained within a
+ * {@link LinkedGhidraFolder}.
+ */
+class LinkedGhidraFile implements LinkedDomainFile {
+
+	private final LinkedGhidraSubFolder parent;
+	private final String fileName;
+
+	LinkedGhidraFile(LinkedGhidraSubFolder parent, String fileName) {
+		this.parent = parent;
+		this.fileName = fileName;
+	}
+
+	@Override
+	public DomainFile getLinkedFile() throws IOException {
+		return parent.getLinkedFile(fileName);
+	}
+
+	private DomainFile getLinkedFileNoError() {
+		return parent.getLinkedFileNoError(fileName);
+	}
+
+	@Override
+	public DomainFolder getParent() {
+		return parent;
+	}
+
+	@Override
+	public String getName() {
+		return fileName;
+	}
+
+	@Override
+	public int compareTo(DomainFile df) {
+		return fileName.compareToIgnoreCase(df.getName());
+	}
+
+	@Override
+	public boolean exists() {
+		return getLinkedFileNoError() != null;
+	}
+
+	@Override
+	public String getFileID() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getFileID() : null;
+	}
+
+	@Override
+	public DomainFile setName(String newName) throws InvalidNameException, IOException {
+		throw new ReadOnlyException("linked file is read only");
+	}
+
+	@Override
+	public String getPathname() {
+		// pathname within project containing folder-link 
+		// getParent() may return a non-linked folder
+		String path = getParent().getPathname();
+		if (path.length() != FileSystem.SEPARATOR.length()) {
+			path += FileSystem.SEPARATOR;
+		}
+		path += fileName;
+		return path;
+	}
+
+	@Override
+	public URL getSharedProjectURL() {
+		URL folderURL = parent.getSharedProjectURL();
+		if (GhidraURL.isServerRepositoryURL(folderURL)) {
+			// Direct URL construction done so that ghidra protocol 
+			// extension may be supported
+			try {
+				return new URL(folderURL.toExternalForm() + fileName);
+			}
+			catch (MalformedURLException e) {
+				// ignore
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public ProjectLocator getProjectLocator() {
+		return parent.getProjectLocator();
+	}
+
+	@Override
+	public String getContentType() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getContentType() : ContentHandler.UNKNOWN_CONTENT;
+	}
+
+	@Override
+	public Class<? extends DomainObject> getDomainObjectClass() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getDomainObjectClass() : DomainObject.class;
+	}
+
+	@Override
+	public ChangeSet getChangesByOthersSinceCheckout() throws VersionException, IOException {
+		return null;
+	}
+
+	@Override
+	public DomainObject getDomainObject(Object consumer, boolean okToUpgrade, boolean okToRecover,
+			TaskMonitor monitor) throws VersionException, IOException, CancelledException {
+		return getReadOnlyDomainObject(consumer, DomainFile.DEFAULT_VERSION, monitor);
+	}
+
+	@Override
+	public DomainObject getOpenedDomainObject(Object consumer) {
+		return null;
+	}
+
+	@Override
+	public DomainObject getReadOnlyDomainObject(Object consumer, int version, TaskMonitor monitor)
+			throws VersionException, IOException, CancelledException {
+		return getLinkedFile().getReadOnlyDomainObject(consumer, version, monitor);
+	}
+
+	@Override
+	public DomainObject getImmutableDomainObject(Object consumer, int version, TaskMonitor monitor)
+			throws VersionException, IOException, CancelledException {
+		return getLinkedFile().getImmutableDomainObject(consumer, version, monitor);
+	}
+
+	@Override
+	public void save(TaskMonitor monitor) throws IOException, CancelledException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public boolean canSave() {
+		return false;
+	}
+
+	@Override
+	public boolean canRecover() {
+		return false;
+	}
+
+	@Override
+	public boolean takeRecoverySnapshot() throws IOException {
+		return true;
+	}
+
+	@Override
+	public boolean isInWritableProject() {
+		return false; // While project may be writeable this folder/file is not
+	}
+
+	@Override
+	public long getLastModifiedTime() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getLastModifiedTime() : 0;
+	}
+
+	@Override
+	public Icon getIcon(boolean disabled) {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getIcon(disabled) : UNSUPPORTED_FILE_ICON;
+	}
+
+	@Override
+	public boolean isCheckedOut() {
+		return false;
+	}
+
+	@Override
+	public boolean isCheckedOutExclusive() {
+		return false;
+	}
+
+	@Override
+	public boolean modifiedSinceCheckout() {
+		return false;
+	}
+
+	@Override
+	public boolean canCheckout() {
+		return false;
+	}
+
+	@Override
+	public boolean canCheckin() {
+		return false;
+	}
+
+	@Override
+	public boolean canMerge() {
+		return false;
+	}
+
+	@Override
+	public boolean canAddToRepository() {
+		return false;
+	}
+
+	@Override
+	public void setReadOnly(boolean state) throws IOException {
+		// ignore
+	}
+
+	@Override
+	public boolean isReadOnly() {
+		return true; // not reflected by icon
+	}
+
+	@Override
+	public boolean isVersioned() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.isVersioned() : false;
+	}
+
+	@Override
+	public boolean isHijacked() {
+		return false;
+	}
+
+	@Override
+	public int getLatestVersion() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getLatestVersion() : DomainFile.DEFAULT_VERSION;
+	}
+
+	@Override
+	public boolean isLatestVersion() {
+		return true;
+	}
+
+	@Override
+	public int getVersion() {
+		// TODO: Do we want to reveal linked-local-project checkout details?
+		return getLatestVersion();
+	}
+
+	@Override
+	public Version[] getVersionHistory() throws IOException {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getVersionHistory() : new Version[0];
+	}
+
+	@Override
+	public void addToVersionControl(String comment, boolean keepCheckedOut, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public boolean checkout(boolean exclusive, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public void checkin(CheckinHandler checkinHandler, boolean okToUpgrade, TaskMonitor monitor)
+			throws IOException, VersionException, CancelledException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public void merge(boolean okToUpgrade, TaskMonitor monitor)
+			throws IOException, VersionException, CancelledException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public void undoCheckout(boolean keep) throws IOException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public void undoCheckout(boolean keep, boolean force) throws IOException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public void terminateCheckout(long checkoutId) throws IOException {
+		throw new UnsupportedOperationException();
+	}
+
+	@Override
+	public ItemCheckoutStatus[] getCheckouts() throws IOException {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getCheckouts() : new ItemCheckoutStatus[0];
+	}
+
+	@Override
+	public ItemCheckoutStatus getCheckoutStatus() throws IOException {
+		// TODO: Do we want to reveal linked-local-project checkout details?
+		return null;
+	}
+
+	@Override
+	public void delete() throws IOException {
+		throw new ReadOnlyException("linked file is read only");
+	}
+
+	@Override
+	public void delete(int version) throws IOException {
+		throw new ReadOnlyException("linked file is read only");
+	}
+
+	@Override
+	public DomainFile moveTo(DomainFolder newParent) throws IOException {
+		throw new ReadOnlyException("linked file is read only");
+	}
+
+	@Override
+	public DomainFile copyTo(DomainFolder newParent, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		return getLinkedFile().copyTo(newParent, monitor);
+	}
+
+	@Override
+	public DomainFile copyVersionTo(int version, DomainFolder destFolder, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		return getLinkedFile().copyVersionTo(version, destFolder, monitor);
+	}
+
+	@Override
+	public DomainFile copyToAsLink(DomainFolder newParent) throws IOException {
+		return getLinkedFile().copyToAsLink(newParent);
+	}
+
+	@Override
+	public boolean isLinkingSupported() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.isLinkingSupported() : false;
+	}
+
+	@Override
+	public List<?> getConsumers() {
+		return List.of();
+	}
+
+	@Override
+	public boolean isChanged() {
+		return false;
+	}
+
+	@Override
+	public boolean isOpen() {
+		return false;  // domain file proxy always used
+	}
+
+	@Override
+	public boolean isBusy() {
+		return false;  // domain file proxy always used
+	}
+
+	@Override
+	public void packFile(File file, TaskMonitor monitor) throws IOException, CancelledException {
+		getLinkedFile().packFile(file, monitor);
+	}
+
+	@Override
+	public Map<String, String> getMetadata() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.getMetadata() : Map.of();
+	}
+
+	@Override
+	public long length() throws IOException {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.length() : 0;
+	}
+
+	@Override
+	public boolean isLinkFile() {
+		DomainFile df = getLinkedFileNoError();
+		return df != null ? df.isLinkFile() : false;
+	}
+
+	@Override
+	public DomainFolder followLink() {
+		try {
+			return FolderLinkContentHandler.getReadOnlyLinkedFolder(this);
+		}
+		catch (IOException e) {
+			Msg.error(this, "Failed to following folder-link: " + getPathname());
+		}
+		return null;
+	}
+
+	@Override
+	public String toString() {
+		return "LinkedGhidraFile: " + getPathname();
+	}
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraFolder.java

@@ -0,0 +1,138 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.net.URL;
+
+import javax.swing.Icon;
+
+import generic.theme.GIcon;
+import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
+import ghidra.framework.store.FileSystem;
+
+/**
+ * {@code LinkedGhidraFolder} provides the base {@link LinkedDomainFolder} implementation which
+ * corresponds to a project folder-link (see {@link FolderLinkContentHandler}).
+ */
+public class LinkedGhidraFolder extends LinkedGhidraSubFolder {
+
+	public static Icon FOLDER_LINK_CLOSED_ICON =
+		new GIcon("icon.content.handler.linked.folder.closed");
+	public static Icon FOLDER_LINK_OPEN_ICON =
+		new GIcon("icon.content.handler.linked.folder.open");
+
+	private final Project activeProject;
+	private final DomainFolder localParent;
+	private final URL folderUrl;
+
+	private String linkedPathname;
+
+	private URL projectUrl;
+
+	/**
+	 * Construct a linked-folder.
+	 * @param activeProject active project responsible for linked project life-cycle management.
+	 * @param localParent local domain folder which contains folder-link or corresponds directly to
+	 * folder-link (name=null).
+	 * @param linkFilename folder-link filename
+	 * @param folderUrl linked folder URL
+	 */
+	LinkedGhidraFolder(Project activeProject, DomainFolder localParent, String linkFilename,
+			URL folderUrl) {
+		super(linkFilename);
+
+		if (!GhidraURL.isServerRepositoryURL(folderUrl) &&
+			!GhidraURL.isLocalProjectURL(folderUrl)) {
+			throw new IllegalArgumentException("Invalid Ghidra URL: " + folderUrl);
+		}
+
+		this.activeProject = activeProject;
+		this.localParent = localParent;
+		this.folderUrl = folderUrl;
+
+		linkedPathname = GhidraURL.getProjectPathname(folderUrl);
+		if (linkedPathname.length() > 0 && linkedPathname.endsWith(FileSystem.SEPARATOR)) {
+			linkedPathname = linkedPathname.substring(0, linkedPathname.length() - 1);
+		}
+	}
+
+	/**
+	 * Get the Ghidra URL associated with this linked folder's project or repository
+	 * @return Ghidra URL associated with this linked folder's project or repository
+	 */
+	public URL getProjectURL() {
+		if (projectUrl == null) {
+			projectUrl = GhidraURL.getProjectURL(folderUrl);
+		}
+		return projectUrl;
+	}
+
+	LinkedGhidraFolder getLinkedRootFolder() {
+		return this;
+	}
+
+	DomainFolder getLinkedFolder(String linkedPath) throws IOException {
+
+		ProjectData projectData = activeProject.addProjectView(getProjectURL(), false);
+		if (projectData == null) {
+			throw new FileNotFoundException();
+		}
+
+		DomainFolder folder = projectData.getFolder(linkedPath);
+		if (folder == null) {
+			throw new FileNotFoundException(folderUrl.toExternalForm());
+		}
+		return folder;
+	}
+
+	@Override
+	public String getLinkedPathname() {
+		return linkedPathname;
+	}
+
+	@Override
+	public ProjectLocator getProjectLocator() {
+		return activeProject.getProjectLocator();
+	}
+
+	@Override
+	public ProjectData getProjectData() {
+		return activeProject.getProjectData();
+	}
+
+	@Override
+	public DomainFolder getParent() {
+		return localParent;
+	}
+
+	@Override
+	public String toString() {
+		return "LinkedGhidraFolder: " + getPathname();
+	}
+
+	@Override
+	public Icon getIcon(boolean isOpen) {
+		return isOpen ? FOLDER_LINK_OPEN_ICON : FOLDER_LINK_CLOSED_ICON;
+	}
+
+	@Override
+	public boolean isLinked() {
+		return true;
+	}
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/LinkedGhidraSubFolder.java

@@ -0,0 +1,294 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.*;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+import javax.swing.Icon;
+
+import ghidra.framework.model.*;
+import ghidra.framework.protocol.ghidra.GhidraURL;
+import ghidra.framework.store.FileSystem;
+import ghidra.util.*;
+import ghidra.util.exception.CancelledException;
+import ghidra.util.task.TaskMonitor;
+
+class LinkedGhidraSubFolder implements LinkedDomainFolder {
+
+	private final LinkedGhidraFolder linkedRootFolder;
+	private final LinkedGhidraSubFolder parent;
+	private final String folderName;
+
+	LinkedGhidraSubFolder(String folderName) {
+		this.linkedRootFolder = getLinkedRootFolder();
+		this.parent = null; // must override getParent()
+		this.folderName = folderName;
+	}
+
+	LinkedGhidraSubFolder(LinkedGhidraSubFolder parent, String folderName) {
+		this.linkedRootFolder = parent.getLinkedRootFolder();
+		this.parent = parent;
+		this.folderName = folderName;
+	}
+
+	/**
+	 * Get the linked root folder which corresponds to a folder-link 
+	 * (see {@link FolderLinkContentHandler}).
+	 * @return linked root folder
+	 */
+	LinkedGhidraFolder getLinkedRootFolder() {
+		return linkedRootFolder;
+	}
+
+	@Override
+	public boolean isInWritableProject() {
+		return false; // While project may be writeable this folder is not
+	}
+
+	@Override
+	public DomainFolder getParent() {
+		return parent;
+	}
+
+	@Override
+	public String getName() {
+		return folderName;
+	}
+
+	@Override
+	public DomainFolder getLinkedFolder() throws IOException {
+		return linkedRootFolder.getLinkedFolder(getLinkedPathname());
+	}
+
+	@Override
+	public int compareTo(DomainFolder df) {
+		return getName().compareToIgnoreCase(df.getName());
+	}
+
+	@Override
+	public DomainFolder setName(String newName) throws InvalidNameException, IOException {
+		throw new ReadOnlyException("linked folder is read only");
+	}
+
+	@Override
+	public URL getSharedProjectURL() {
+		URL projectURL = getLinkedRootFolder().getProjectURL();
+		if (GhidraURL.isServerRepositoryURL(projectURL)) {
+			String urlStr = projectURL.toExternalForm();
+			if (urlStr.endsWith(FileSystem.SEPARATOR)) {
+				urlStr = urlStr.substring(0, urlStr.length() - 1);
+			}
+			String path = getLinkedPathname();
+			if (!path.endsWith(FileSystem.SEPARATOR)) {
+				path += FileSystem.SEPARATOR;
+			}
+			try {
+				return new URL(urlStr + path);
+			}
+			catch (MalformedURLException e) {
+				// ignore
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public ProjectLocator getProjectLocator() {
+		return parent.getProjectLocator();
+	}
+
+	@Override
+	public ProjectData getProjectData() {
+		return parent.getProjectData();
+	}
+
+	@Override
+	public String getPathname() {
+		// pathname within project containing folder-link 
+		// getParent() may return a non-linked folder
+		String path = getParent().getPathname();
+		if (path.length() != FileSystem.SEPARATOR.length()) {
+			path += FileSystem.SEPARATOR;
+		}
+		path += folderName;
+		return path;
+	}
+
+	/**
+	 * Get the pathname of this folder within the linked-project/repository
+	 * @return absolute linked folder path within the linked-project/repository
+	 */
+	public String getLinkedPathname() {
+		String path = parent.getLinkedPathname();
+		if (!path.endsWith(FileSystem.SEPARATOR)) {
+			path += FileSystem.SEPARATOR;
+		}
+		path += folderName;
+		return path;
+	}
+
+	@Override
+	public LinkedGhidraSubFolder[] getFolders() {
+		try {
+			DomainFolder linkedFolder = getLinkedFolder();
+			DomainFolder[] folders = linkedFolder.getFolders();
+			LinkedGhidraSubFolder[] linkedSubFolders = new LinkedGhidraSubFolder[folders.length];
+			for (int i = 0; i < folders.length; i++) {
+				linkedSubFolders[i] = new LinkedGhidraSubFolder(this, folders[i].getName());
+			}
+			return linkedSubFolders;
+		}
+		catch (IOException e) {
+			Msg.error(this, "Linked folder failure: " + e.getMessage());
+			return new LinkedGhidraSubFolder[0];
+		}
+	}
+
+	@Override
+	public LinkedGhidraSubFolder getFolder(String name) {
+		try {
+			DomainFolder linkedFolder = getLinkedFolder();
+			DomainFolder f = linkedFolder.getFolder(name);
+			if (f != null) {
+				return new LinkedGhidraSubFolder(this, name);
+			}
+		}
+		catch (IOException e) {
+			Msg.error(this, "Linked folder failure: " + e.getMessage());
+		}
+		return null;
+	}
+
+	@Override
+	public DomainFile[] getFiles() {
+		try {
+			DomainFolder linkedFolder = getLinkedFolder();
+			DomainFile[] files = linkedFolder.getFiles();
+			LinkedGhidraFile[] linkedSubFolders = new LinkedGhidraFile[files.length];
+			for (int i = 0; i < files.length; i++) {
+				linkedSubFolders[i] = new LinkedGhidraFile(this, files[i].getName());
+			}
+			return linkedSubFolders;
+		}
+		catch (IOException e) {
+			Msg.error(this, "Linked folder failure: " + e.getMessage());
+			return new LinkedGhidraFile[0];
+		}
+	}
+
+	/**
+	 * Get the true file within this linked folder.
+	 * @param name file name
+	 * @return file or null if not found or error occurs
+	 */
+	public DomainFile getLinkedFileNoError(String name) {
+		try {
+			DomainFolder linkedFolder = getLinkedFolder();
+			return linkedFolder.getFile(name);
+		}
+		catch (IOException e) {
+			Msg.error(this, "Linked folder failure: " + e.getMessage());
+		}
+		return null;
+	}
+
+	DomainFile getLinkedFile(String name) throws IOException {
+		DomainFolder linkedFolder = getLinkedFolder();
+		DomainFile df = linkedFolder.getFile(name);
+		if (df == null) {
+			throw new FileNotFoundException("linked-file '" + name + "' not found");
+		}
+		return df;
+	}
+
+	@Override
+	public DomainFile getFile(String name) {
+		DomainFile f = getLinkedFileNoError(name);
+		return f != null ? new LinkedGhidraFile(this, name) : null;
+	}
+
+	@Override
+	public boolean isEmpty() {
+		try {
+			DomainFolder linkedFolder = getLinkedFolder();
+			return linkedFolder.isEmpty();
+		}
+		catch (IOException e) {
+			Msg.error(this, "Linked folder failure: " + e.getMessage());
+			// TODO: what should we return if folder not found or error occurs?
+			// True is returned to allow this method to be used to avoid continued access.
+			return true;
+		}
+	}
+
+	@Override
+	public DomainFile createFile(String name, DomainObject obj, TaskMonitor monitor)
+			throws InvalidNameException, IOException, CancelledException {
+		throw new ReadOnlyException("linked folder is read only");
+	}
+
+	@Override
+	public DomainFile createFile(String name, File packFile, TaskMonitor monitor)
+			throws InvalidNameException, IOException, CancelledException {
+		throw new ReadOnlyException("linked folder is read only");
+	}
+
+	@Override
+	public DomainFolder createFolder(String name) throws InvalidNameException, IOException {
+		throw new ReadOnlyException("linked folder is read only");
+	}
+
+	@Override
+	public void delete() throws IOException {
+		throw new ReadOnlyException("linked folder is read only");
+	}
+
+	@Override
+	public DomainFolder moveTo(DomainFolder newParent) throws IOException {
+		throw new ReadOnlyException("linked folder is read only");
+	}
+
+	@Override
+	public DomainFolder copyTo(DomainFolder newParent, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		DomainFolder linkedFolder = getLinkedFolder();
+		return linkedFolder.copyTo(newParent, monitor);
+	}
+
+	@Override
+	public DomainFile copyToAsLink(DomainFolder newParent) throws IOException {
+		DomainFolder linkedFolder = getLinkedFolder();
+		return linkedFolder.copyToAsLink(newParent);
+	}
+
+	@Override
+	public void setActive() {
+		// do nothing
+	}
+
+	@Override
+	public String toString() {
+		return "LinkedGhidraSubFolder: " + getPathname();
+	}
+
+	@Override
+	public Icon getIcon(boolean isOpen) {
+		return isOpen ? OPEN_FOLDER_ICON : CLOSED_FOLDER_ICON;
+	}
+
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ProjectFileManager.java

@@ -16,13 +16,12 @@
 package ghidra.framework.data;
 
 import java.io.*;
-import java.net.URL;
 import java.util.*;
 
+import docking.widgets.OptionDialog;
 import generic.timer.GhidraSwinglessTimer;
 import ghidra.framework.client.*;
 import ghidra.framework.model.*;
-import ghidra.framework.protocol.ghidra.GhidraURL;
 import ghidra.framework.remote.User;
 import ghidra.framework.store.*;
 import ghidra.framework.store.FileSystem;
@@ -82,6 +81,7 @@ public class ProjectFileManager implements ProjectData {
 
 	private TaskMonitorAdapter projectDisposalMonitor = new TaskMonitorAdapter();
 
+	private ProjectLock projectLock;
 	private String owner;
 
 	/**
@@ -91,12 +91,16 @@ public class ProjectFileManager implements ProjectData {
 	 * @param resetOwner true to reset the project owner
 	 * @throws IOException if an i/o error occurs
 	 * @throws NotOwnerException if inProject is true and user is not owner
+	 * @throws LockException if {@code isInWritableProject} is true and unable to establish project 
+	 * write lock (i.e., project in-use)
 	 * @throws FileNotFoundException if project directory not found
 	 */
 	public ProjectFileManager(ProjectLocator localStorageLocator, boolean isInWritableProject,
-			boolean resetOwner) throws NotOwnerException, IOException {
+			boolean resetOwner) throws NotOwnerException, IOException, LockException {
 
 		this.localStorageLocator = localStorageLocator;
+		boolean success = false;
+		try {
 			init(false, isInWritableProject);
 			if (resetOwner) {
 				owner = SystemUtilities.getUserName();
@@ -116,10 +120,16 @@ public class ProjectFileManager implements ProjectData {
 			synchronized (fileSystem) {
 				getVersionedFileSystem(isInWritableProject);
 				rootFolderData = new RootGhidraFolderData(this, listenerList);
-			versionedFSListener = new MyFileSystemListener();
+				initVersionedFSListener();
-			versionedFileSystem.addFileSystemListener(versionedFSListener);
 				scheduleUserDataReconcilation();
 			}
+			success = true;
+		}
+		finally {
+			if (!success) {
+				dispose();
+			}
+		}
 	}
 
 	/**
@@ -128,34 +138,75 @@ public class ProjectFileManager implements ProjectData {
 	 * @param repository a repository if this is a shared project or null if it is a private project
 	 * @param isInWritableProject true if project content is writable, false if project is read-only
 	 * @throws IOException if an i/o error occurs
+	 * @throws LockException if {@code isInWritableProject} is true and unable to establish project 
+	 * lock (i.e., project in-use)
 	 */
 	public ProjectFileManager(ProjectLocator localStorageLocator, RepositoryAdapter repository,
-			boolean isInWritableProject) throws IOException {
+			boolean isInWritableProject) throws IOException, LockException {
 		this.localStorageLocator = localStorageLocator;
 		this.repository = repository;
+		boolean success = false;
+		try {
 			init(true, isInWritableProject);
 			synchronized (fileSystem) {
 				createVersionedFileSystem();
 				rootFolderData = new RootGhidraFolderData(this, listenerList);
-			versionedFSListener = new MyFileSystemListener();
+				initVersionedFSListener();
-			versionedFileSystem.addFileSystemListener(versionedFSListener);
+			}
+			success = true;
+		}
+		finally {
+			if (!success) {
+				dispose();
+			}
 		}
 	}
 
-	ProjectFileManager(LocalFileSystem fileSystem, FileSystem versionedFileSystem) {
+	/**
+	 * Constructor for test use only.  A non-existing {@link ProjectLocator} is used without
+	 * project locking.
+	 * @param fileSystem an existing non-versioned local file-system
+	 * @param versionedFileSystem an existing versioned file-system
+	 * @throws IOException if an IO error occurs
+	 */
+	ProjectFileManager(LocalFileSystem fileSystem, FileSystem versionedFileSystem)
+			throws IOException {
 		this.localStorageLocator = new ProjectLocator(null, "Test");
 		owner = SystemUtilities.getUserName();
+		boolean success = false;
+		try {
 			synchronized (fileSystem) {
 				this.fileSystem = fileSystem;
 				this.versionedFileSystem = versionedFileSystem;
 				rootFolderData = new RootGhidraFolderData(this, listenerList);
-			versionedFSListener = new MyFileSystemListener();
+				initVersionedFSListener();
-			versionedFileSystem.addFileSystemListener(versionedFSListener);
 				scheduleUserDataReconcilation();
+				success = true;
+			}
+		}
+		finally {
+			if (!success) {
+				dispose();
+			}
 		}
 	}
 
-	private void init(boolean create, boolean isInWritableProject) throws IOException {
+	private void initVersionedFSListener() throws IOException {
+		// Listener not installed for local read-only versioned file-system
+		if (versionedFileSystem.isShared() || !versionedFileSystem.isReadOnly()) {
+			if (versionedFSListener == null) {
+				versionedFSListener = new MyFileSystemListener();
+			}
+			versionedFileSystem.addFileSystemListener(versionedFSListener);
+		}
+		else {
+			versionedFSListener = null;
+		}
+	}
+
+	private void init(boolean create, boolean isInWritableProject)
+			throws IOException, LockException {
+
 		projectDir = localStorageLocator.getProjectDir();
 		properties = new PropertyFile(projectDir, PROPERTY_FILENAME, "/", PROPERTY_FILENAME);
 		if (create) {
@@ -163,11 +214,13 @@ public class ProjectFileManager implements ProjectData {
 				throw new DuplicateFileException(
 					"Project directory already exists: " + projectDir.getCanonicalPath());
 			}
+			File markerFile = localStorageLocator.getMarkerFile();
+			if (markerFile.exists()) {
+				throw new DuplicateFileException(
+					"Project marker file already exists: " + markerFile.getCanonicalPath());
+			}
 			projectDir.mkdir();
 			localStorageLocator.getMarkerFile().createNewFile();
-			owner = SystemUtilities.getUserName();
-			properties.putString(OWNER, owner);
-			properties.writeState();
 		}
 		else {
 			if (!projectDir.isDirectory()) {
@@ -178,22 +231,92 @@ public class ProjectFileManager implements ProjectData {
 					throw new ReadOnlyException(
 						"Project " + localStorageLocator.getName() + " is read-only");
 				}
-				properties.readState();
 				owner = properties.getString(OWNER, SystemUtilities.getUserName());
 			}
-			else if (isInWritableProject) {
-				owner = SystemUtilities.getUserName();
-				properties.putString(OWNER, owner);
-				properties.writeState();
-			}
 			else {
 				owner = "<unknown>"; // Unknown owner
 			}
 		}
+
+		if (isInWritableProject) {
+			initLock(create);
+		}
+
 		getPrivateFileSystem(create, isInWritableProject);
 		getUserFileSystem(isInWritableProject);
 	}
 
+	private void initLock(boolean creatingProject) throws LockException, IOException {
+		this.projectLock = getProjectLock(localStorageLocator, !creatingProject);
+		if (projectLock == null) {
+			throw new LockException("Unable to lock project! " + localStorageLocator);
+		}
+
+		if (!properties.exists()) {
+			owner = SystemUtilities.getUserName();
+			properties.putString(OWNER, owner);
+			properties.writeState();
+		}
+	}
+
+	/**
+	 * Creates a ProjectLock and attempts to lock it. This handles the case
+	 * where the project was previously locked.
+	 * 
+	 * @param locator the project locator
+	 * @param allowInteractiveForce if true, when a lock cannot be obtained, the
+	 *            user will be prompted
+	 * @return A locked ProjectLock or null if lock fails
+	 */
+	private ProjectLock getProjectLock(ProjectLocator locator, boolean allowInteractiveForce) {
+		ProjectLock lock = new ProjectLock(locator);
+		if (lock.lock()) {
+			return lock;
+		}
+
+		// in headless mode, just spit out an error
+		if (!allowInteractiveForce || SystemUtilities.isInHeadlessMode()) {
+			return null;
+		}
+
+		String projectStr = "Project: " + HTMLUtilities.escapeHTML(locator.getLocation()) +
+			System.getProperty("file.separator") + HTMLUtilities.escapeHTML(locator.getName());
+		String lockInformation = lock.getExistingLockFileInformation();
+		if (!lock.canForceLock()) {
+			Msg.showInfo(getClass(), null, "Project Locked",
+				"<html>Project is locked. You have another instance of Ghidra<br>" +
+					"already running with this project open (locally or remotely).<br><br>" +
+					projectStr + "<br><br>" + "Lock information: " + lockInformation);
+			return null;
+		}
+
+		int userChoice = OptionDialog.showOptionDialog(null, "Project Locked - Delete Lock?",
+			"<html>Project is locked. You may have another instance of Ghidra<br>" +
+				"already running with this project opened (locally or remotely).<br>" + projectStr +
+				"<br><br>" + "If this is not the case, you can delete the lock file:  <br><b>" +
+				locator.getProjectLockFile().getAbsolutePath() + "</b>.<br><br>" +
+				"Lock information: " + lockInformation,
+			"Delete Lock", OptionDialog.QUESTION_MESSAGE);
+		if (userChoice == OptionDialog.OPTION_ONE) { // Delete Lock
+			if (lock.forceLock()) {
+				return lock;
+			}
+
+			Msg.showError(this, null, "Error", "Attempt to force lock failed! " + locator);
+		}
+		return null;
+	}
+
+	/**
+	 * Determine if the specified project location currently has a write lock.
+	 * @param locator project storage locator
+	 * @return true if project data current has write-lock else false
+	 */
+	public static boolean isLocked(ProjectLocator locator) {
+		ProjectLock lock = new ProjectLock(locator);
+		return lock.isLocked();
+	}
+
 	@Override
 	public int getMaxNameLength() {
 		return fileSystem.getMaxNameLength();
@@ -314,8 +437,9 @@ public class ProjectFileManager implements ProjectData {
 
 	/**
 	 * Change the versioned filesystem associated with this project file manager.
-	 * This method is provided for testing.  Care should be taken when using a
+	 * This method is provided for testing (see {@code FakeSharedProject}).  
-	 * LocalFileSystem in a shared capacity since locking is not supported.
+	 * Care should be taken when using a LocalFileSystem in a shared capacity since 
+	 * locking is not supported.
 	 * @param fs versioned filesystem
 	 * @throws IOException if an IO error occurs
 	 */
@@ -323,9 +447,11 @@ public class ProjectFileManager implements ProjectData {
 		if (!fs.isVersioned()) {
 			throw new IllegalArgumentException("versioned filesystem required");
 		}
+		if (versionedFSListener != null) {
 			versionedFileSystem.removeFileSystemListener(versionedFSListener);
+		}
 		versionedFileSystem = fs;
-		versionedFileSystem.addFileSystemListener(versionedFSListener);
+		initVersionedFSListener();
 		rootFolderData.setVersionedFileSystem(versionedFileSystem);
 	}
 
@@ -385,19 +511,37 @@ public class ProjectFileManager implements ProjectData {
 	}
 
 	@Override
-	public GhidraFolder getFolder(String path) {
+	public DomainFolder getFolder(String path) {
 		int len = path.length();
 		if (len == 0 || path.charAt(0) != FileSystem.SEPARATOR_CHAR) {
 			throw new IllegalArgumentException(
 				"Absolute path must begin with '" + FileSystem.SEPARATOR_CHAR + "'");
 		}
-		try {
+
-			return getRootFolder().getFolderPathData(path).getDomainFolder();
+		DomainFolder folder = getRootFolder();
+		String[] split = path.split(FileSystem.SEPARATOR);
+		if (split.length == 0) {
+			return folder;
 		}
-		catch (FileNotFoundException e) {
+
+		for (int i = 1; i < split.length; i++) {
+			DomainFolder subFolder = folder.getFolder(split[i]);
+			if (subFolder == null) {
+				// Check for folder link-file if folder not found
+				// NOTE: if real folder name matches link-file name it will block
+				// use of folder link-file.
+				DomainFile file = folder.getFile(split[i]);
+				if (file != null && file.isLinkFile()) {
+					subFolder = file.followLink();
+				}
+				if (subFolder == null) {
 					return null;
 				}
 			}
+			folder = subFolder;
+		}
+		return folder;
+	}
 
 	@Override
 	public int getFileCount() {
@@ -468,19 +612,6 @@ public class ProjectFileManager implements ProjectData {
 		return fileIndex.getFileByID(fileID);
 	}
 
-	@Override
-	public URL getSharedFileURL(String path) {
-		if (repository != null) {
-			DomainFile df = getFile(path);
-			if (df != null && df.isVersioned()) {
-				ServerInfo server = repository.getServerInfo();
-				return GhidraURL.makeURL(server.getServerName(), server.getPortNumber(),
-					repository.getName(), path);
-			}
-		}
-		return null;
-	}
-
 	public void releaseDomainFiles(Object consumer) {
 		for (DomainObjectAdapter domainObj : openDomainObjects.values()) {
 			try {
@@ -707,7 +838,11 @@ public class ProjectFileManager implements ProjectData {
 			monitor.checkCanceled();
 			LocalFolderItem item = fileSystem.getItem(folderPath, name);
 			if (item.getCheckoutId() != FolderItem.DEFAULT_CHECKOUT_ID) {
-				checkoutList.add(new GhidraFile(getFolder(folderPath), name));
+				GhidraFolderData folderData =
+					getRootFolderData().getFolderPathData(folderPath, false);
+				if (folderData != null) {
+					checkoutList.add(new GhidraFile(folderData.getDomainFolder(), name));
+				}
 			}
 		}
 
@@ -1037,15 +1172,23 @@ public class ProjectFileManager implements ProjectData {
 			listenerList.clearAll();
 		}
 
+		if (fileSystem != null) {
 			synchronized (fileSystem) {
-			rootFolderData.dispose();
+				if (versionedFSListener != null) {
-			fileSystem.dispose();
-			versionedFileSystem.dispose();
 					versionedFileSystem.removeFileSystemListener(versionedFSListener);
+				}
 				if (repository != null) {
 					repository.disconnect();
 					repository = null;
 				}
+				rootFolderData.dispose();
+				versionedFileSystem.dispose();
+				fileSystem.dispose();
+			}
+		}
+
+		if (projectLock != null) {
+			projectLock.release();
 		}
 	}
 

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/ProjectLock.java

@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package ghidra.framework.project;
+package ghidra.framework.data;
 
 import java.io.File;
 

Ghidra/Framework/Project/src/main/java/ghidra/framework/data/URLLinkObject.java

@@ -0,0 +1,101 @@
+/* ###
+ * IP: GHIDRA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package ghidra.framework.data;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+
+import javax.help.UnsupportedOperationException;
+
+import db.DBHandle;
+import ghidra.framework.model.DomainFile;
+import ghidra.framework.model.DomainObject;
+import ghidra.framework.protocol.ghidra.GhidraURL;
+import ghidra.util.exception.CancelledException;
+import ghidra.util.task.TaskMonitor;
+
+/**
+ * {@code DomainObjectAdapterLink} object provides a Ghidra URL (see {@link GhidraURL}) wrapper
+ * where the URL is intended to refer to a {@link DomainFile} within another local or remote
+ * project/repository.  Link files which correspond to this type of {@link DomainObject} are
+ * not intended to be modified and should be created or deleted.  A checkout may be used when
+ * an offline copy is required but otherwise serves no purpose since a modification and checkin
+ * is not supported. 
+ */
+public class URLLinkObject extends DomainObjectAdapterDB {
+
+	// Use a reduced DB buffer size to reduce file size for minimal content.
+	// This will allow a 4-KByte DB buffer file to hold a URL upto ~470 bytes long.
+	// Longer URLs will rely on 1-KByte chained buffers which will increase file length.
+	private static final int DB_BUFFER_SIZE = 1024;
+
+	private URL url;
+
+	/**
+	 * Constructs a new link file object
+	 * @param name link name
+	 * @param ghidraUrl link URL
+	 * @param consumer the object that is using this program.
+	 * @throws IOException if there is an error accessing the database or invalid URL specified.
+	 */
+	public URLLinkObject(String name, URL ghidraUrl, Object consumer) throws IOException {
+		super(new DBHandle(DB_BUFFER_SIZE), name, 500, consumer);
+		metadata.put(LinkHandler.URL_METADATA_KEY, ghidraUrl.toString());
+		updateMetadata();
+	}
+
+	/**
+	 * Constructs a link file object from a DBHandle (read-only)
+	 * @param dbh a handle to an open program database.
+	 * @param consumer the object that keeping the program open.
+	 * @throws IOException if an error accessing the database occurs.
+	 */
+	public URLLinkObject(DBHandle dbh, Object consumer) throws IOException {
+		super(dbh, "Untitled", 500, consumer);
+		loadMetadata();
+		String urlText = metadata.get(LinkHandler.URL_METADATA_KEY);
+		if (urlText == null) {
+			throw new IOException("Null link object");
+		}
+		url = new URL(urlText);
+	}
+
+	@Override
+	public String getDescription() {
+		return "Link-File";
+	}
+
+	/**
+	 * Get link URL
+	 * @return link URL
+	 */
+	public URL getLink() {
+		return url;
+	}
+
+	@Override
+	public final boolean isChangeable() {
+		return false;
+	}
+
+	@Override
+	public final void saveToPackedFile(File outputFile, TaskMonitor monitor)
+			throws IOException, CancelledException {
+		throw new UnsupportedOperationException();
+	}
+
+}

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/FrontEndPlugin.java

@@ -40,6 +40,8 @@ import generic.theme.GIcon;
 import ghidra.app.plugin.PluginCategoryNames;
 import ghidra.framework.GenericRunInfo;
 import ghidra.framework.client.*;
+import ghidra.framework.data.FolderLinkContentHandler;
+import ghidra.framework.data.LinkedGhidraFolder;
 import ghidra.framework.main.datatable.ProjectDataTablePanel;
 import ghidra.framework.main.datatree.*;
 import ghidra.framework.main.projectdata.actions.*;
@@ -69,7 +71,7 @@ import ghidra.util.filechooser.GhidraFileFilter;
 )
 //@formatter:on
 public class FrontEndPlugin extends Plugin
-		implements FrontEndService, RemoteAdapterListener, ProgramaticUseOnly {
+		implements FrontEndService, RemoteAdapterListener, ProjectViewListener, ProgramaticUseOnly {
 
 	private final static String TITLE_PREFIX = "Ghidra: ";
 	private final static String EXPORT_TOOL_ACTION_NAME = "Export Tool";
@@ -128,6 +130,7 @@ public class FrontEndPlugin extends Plugin
 	private ClearCutAction clearCutAction;
 	private ProjectDataCopyAction copyAction;
 	private ProjectDataPasteAction pasteAction;
+	private ProjectDataPasteLinkAction pasteLinkAction;
 	private ProjectDataRenameAction renameAction;
 	private ProjectDataOpenDefaultToolAction openAction;
 	private ProjectDataExpandAction<FrontEndProjectTreeContext> expandAction;
@@ -217,6 +220,7 @@ public class FrontEndPlugin extends Plugin
 		clearCutAction = new ClearCutAction(owner);
 		copyAction = new ProjectDataCopyAction(owner, groupName);
 		pasteAction = new ProjectDataPasteAction(owner, groupName);
+		pasteLinkAction = new ProjectDataPasteLinkAction(owner, groupName);
 
 		groupName = "Delete/Rename";
 		renameAction = new ProjectDataRenameAction(owner, groupName);
@@ -239,6 +243,7 @@ public class FrontEndPlugin extends Plugin
 		tool.addAction(clearCutAction);
 		tool.addAction(copyAction);
 		tool.addAction(pasteAction);
+		tool.addAction(pasteLinkAction);
 		tool.addAction(deleteAction);
 		tool.addAction(openAction);
 		tool.addAction(renameAction);
@@ -393,6 +398,10 @@ public class FrontEndPlugin extends Plugin
 			toolChest.addToolChestChangeListener(toolBar);
 			toolChest.addToolChestChangeListener(toolChestChangeListener);
 			createToolSpecificOpenActions();
+
+			// Add project view listener
+			activeProject.addProjectViewListener(this);
+
 			// Add the repository listener
 			RepositoryAdapter repository = activeProject.getRepository();
 			if (repository != null) {
@@ -403,6 +412,16 @@ public class FrontEndPlugin extends Plugin
 //        gui.validate();
 	}
 
+	@Override
+	public void viewedProjectAdded(URL projectView) {
+		SwingUtilities.invokeLater(() -> rebuildRecentMenus());
+	}
+
+	@Override
+	public void viewedProjectRemoved(URL projectView) {
+		SwingUtilities.invokeLater(() -> rebuildRecentMenus());
+	}
+
 	/**
 	 * sets the name of the project, using the default name if no project is active
 	 */
@@ -1074,12 +1093,23 @@ public class FrontEndPlugin extends Plugin
 	}
 
 	public void openDomainFile(DomainFile domainFile) {
+
+		if (FolderLinkContentHandler.FOLDER_LINK_CONTENT_TYPE.equals(domainFile.getContentType())) {
+			showLinkedFolder(domainFile);
+			return;
+		}
+
 		Project project = tool.getProject();
 		final ToolServices toolServices = project.getToolServices();
 		ToolTemplate defaultToolTemplate = toolServices.getDefaultToolTemplate(domainFile);
+		if (defaultToolTemplate != null) {
+			ToolButton button = toolBar.getToolButtonForToolConfig(defaultToolTemplate);
+			if (button != null) {
+				button.launchTool(domainFile);
+				return;
+			}
+		}
 
-		if (defaultToolTemplate == null) {
-			// assume no tools in the tool chest
 		Msg.showInfo(this, tool.getToolFrame(), "Cannot Find Tool",
 			"<html>Cannot find tool to open file: <b>" +
 				HTMLUtilities.escapeHTML(domainFile.getName()) +
@@ -1087,11 +1117,32 @@ public class FrontEndPlugin extends Plugin
 				"<b>Tools->Import Default Tools...</b> menu.  Alternatively, you can " +
 				"use <b>Tool->Set Tool Associations</b> menu to change how Ghidra " +
 				"opens this type of file");
+	}
+
+	private void showLinkedFolder(DomainFile domainFile) {
+
+		try {
+			LinkedGhidraFolder linkedFolder =
+				FolderLinkContentHandler.getReadOnlyLinkedFolder(domainFile);
+			if (linkedFolder == null) {
+				return;  // unsupported use
+			}
+
+			ProjectDataTreePanel dtp = projectDataPanel.openView(linkedFolder.getProjectURL());
+			if (dtp == null) {
 				return;
 			}
 
-		ToolButton button = toolBar.getToolButtonForToolConfig(defaultToolTemplate);
+			DomainFolder domainFolder = linkedFolder.getLinkedFolder();
-		button.launchTool(domainFile);
+			if (domainFolder != null) {
+				// delayed to ensure tree is displayd
+				Swing.runLater(() -> dtp.selectDomainFolder(domainFolder));
+			}
+		}
+		catch (IOException e) {
+			Msg.showError(this, projectDataPanel, "Linked-folder failure: " + domainFile.getName(),
+				e);
+		}
 
 	}
 

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/ProjectActionManager.java

@@ -554,10 +554,15 @@ class ProjectActionManager {
 			return;
 		}
 
-		ProjectDataPanel pdp = plugin.getProjectDataPanel();
+		try {
-		pdp.openView(view);
+			activeProject.addProjectView(view, true); // listener will trigger data panel panel display
-		// also update the recent views menu
+		}
-		plugin.rebuildRecentMenus();
+		catch (IOException e) {
+			ProjectManager projectManager = tool.getProjectManager();
+			projectManager.forgetViewedProject(view);
+			Msg.showError(getClass(), tool.getToolFrame(), "Error Adding View",
+				"Failed to view project/repository: " + e.getMessage(), e);
+		}
 	}
 
 	private void editProjectAccess() {

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/ProjectDataPanel.java

@@ -27,6 +27,7 @@ import javax.swing.*;
 import docking.ActionContext;
 import docking.ComponentProvider;
 import docking.widgets.tabbedpane.DockingTabRenderer;
+import ghidra.framework.client.NotConnectedException;
 import ghidra.framework.main.datatable.ProjectDataTablePanel;
 import ghidra.framework.main.datatree.ProjectDataTreePanel;
 import ghidra.framework.model.*;
@@ -40,7 +41,7 @@ import help.HelpService;
  * Manages the data tree for the active project, and the trees for the
  * project views.
  */
-class ProjectDataPanel extends JSplitPane {
+class ProjectDataPanel extends JSplitPane implements ProjectViewListener {
 	private final static String BORDER_PREFIX = "Active Project: ";
 	private final static String READ_ONLY_BORDER = "READ-ONLY Project Data";
 	private final static int TYPICAL_NUM_VIEWS = 2;
@@ -155,6 +156,21 @@ class ProjectDataPanel extends JSplitPane {
 		setViewsVisible(views.length > 0);
 	}
 
+	@Override
+	public void viewedProjectAdded(URL projectView) {
+		SwingUtilities.invokeLater(() -> openView(projectView));
+	}
+
+	@Override
+	public void viewedProjectRemoved(URL projectView) {
+		SwingUtilities.invokeLater(() -> {
+			ProjectDataTreePanel dtp = getViewPanel(projectView);
+			if (dtp != null) {
+				viewRemoved(dtp, projectView, false);
+			}
+		});
+	}
+
 	private void clearReadOnlyViews() {
 		readOnlyTab.removeAll();
 		readOnlyViews.clear();
@@ -167,7 +183,13 @@ class ProjectDataPanel extends JSplitPane {
 		this.setDividerLocation(visible ? DIVIDER_LOCATION : 1.0);
 	}
 
-	void openView(URL projectView) {
+	/**
+	 * Open specified project URL in tabbed READ-Only project views
+	 * @param projectView project URL to be opened/added to view
+	 * @return corresponding tree panel or null on failure
+	 */
+	ProjectDataTreePanel openView(URL projectView) {
+
 		ProjectManager projectManager = tool.getProjectManager();
 		Project activeProject = tool.getProject();
 
@@ -176,19 +198,23 @@ class ProjectDataPanel extends JSplitPane {
 		if (dtp != null) {
 			readOnlyTab.setSelectedComponent(dtp);
 			try {
-				activeProject.addProjectView(projectView);
+				activeProject.addProjectView(projectView, true);
 				projectManager.rememberViewedProject(projectView);
+				return dtp;
 			}
 			catch (Exception e) {
 				projectManager.forgetViewedProject(projectView);
 				Msg.showError(getClass(), tool.getToolFrame(), "Error Adding View", e.toString());
 			}
-			return;
+			return null;
 		}
 
 		try {
 			// TODO: addProjectView should be done in a model task
-			ProjectData projectData = activeProject.addProjectView(projectView);
+			ProjectData projectData = activeProject.addProjectView(projectView, true);
+			if (projectData == null) {
+				return null; // repository connection may have been cancelled
+			}
 			projectManager.rememberViewedProject(projectView);
 			String viewName = projectData.getProjectLocator().getName();
 			final ProjectDataTreePanel newPanel =
@@ -204,14 +230,21 @@ class ProjectDataPanel extends JSplitPane {
 			readOnlyTab.setSelectedIndex(0);
 			readOnlyViews.put(projectData.getProjectLocator(), newPanel);
 			setViewsVisible(true);
+			return newPanel;
+		}
+		catch (NotConnectedException e) {
+			// already handled (e..g, cancelled login) - ignore
 		}
 		catch (Exception e) {
 			projectManager.forgetViewedProject(projectView);
 			Msg.showError(getClass(), tool.getToolFrame(), "Error Adding View",
-				"Failed to view project/repository: " + e.getMessage());
+				"Failed to view project/repository: " + e.getMessage(), e);
 		}
+		finally {
 			validate();
 		}
+		return null;
+	}
 
 	ProjectLocator[] getProjectViews() {
 		int numViews = readOnlyViews.size();
@@ -315,6 +348,7 @@ class ProjectDataPanel extends JSplitPane {
 			treePanel.setProjectData(project.getName(), project.getProjectData());
 			tablePanel.setProjectData(project.getName(), project.getProjectData());
 			populateReadOnlyViews(project);
+			project.addProjectViewListener(this);
 		}
 		else {
 			tablePanel.setProjectData("No Active Project", null);

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatable/ProjectDataTablePanel.java

@@ -182,9 +182,12 @@ public class ProjectDataTablePanel extends JPanel {
 			this.projectData.removeDomainFolderChangeListener(changeListener);
 			model.setProjectData(null);
 			SystemUtilities.runSwingLater(() -> {
-				GGlassPane glassPane = (GGlassPane) gTable.getRootPane().getGlassPane();
+				JRootPane rootPane = gTable.getRootPane();
+				if (rootPane != null) {
+					GGlassPane glassPane = (GGlassPane) rootPane.getGlassPane();
 					glassPane.removePainter(painter);
 					glassPane.addPainter(painter);
+				}
 			});
 		}
 	}

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatable/ProjectTreeAction.java

@@ -70,7 +70,7 @@ public abstract class ProjectTreeAction extends DockingAction {
 
 	@Override
 	public boolean isAddToPopup(ActionContext context) {
-		if (!isEnabledForContext(context)) {
+		if (!(context instanceof FrontEndProjectTreeContext)) {
 			return false;
 		}
 		return isAddToPopup((FrontEndProjectTreeContext) context);

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ChangeManager.java

@@ -176,40 +176,15 @@ class ChangeManager implements DomainFolderChangeListener {
 			if (lazy && !folderNode.isLoaded()) {
 				return null; // not visited 
 			}
-			// must look at all children since a folder and file may have the same name
+			folderNode =
-			boolean found = false;
+				(DomainFolderNode) folderNode.getChild(name, n -> (n instanceof DomainFolderNode));
-			for (GTreeNode node : folderNode.getChildren()) {
+			if (folderNode == null) {
-				if (!(node instanceof DomainFolderNode)) {
-					continue;
-				}
-				if (name.equals(node.getName())) {
-					folderNode = (DomainFolderNode) node;
-					found = true;
-					break;
-				}
-			}
-			if (!found) {
 				return null;
 			}
 		}
 		return folderNode;
 	}
 
-//	private DomainFileNode findDomainFileNode(DomainFolder parent, String name, boolean lazy) {
-//		DomainFolderNode folderNode = findDomainFolderNode(parent, lazy);
-//		if (folderNode == null) {
-//			return null;
-//		}
-//		if (lazy && !folderNode.isChildrenLoadedOrInProgress()) {
-//			return null; // not visited 
-//		}
-//		GTreeNode child = folderNode.getChild(name);
-//		if (child instanceof DomainFileNode) {
-//			return (DomainFileNode) child;
-//		}
-//		return null;
-//	}
-
 	private DomainFileNode findDomainFileNode(DomainFile domainFile, boolean lazy) {
 		DomainFolderNode folderNode = findDomainFolderNode(domainFile.getParent(), lazy);
 		if (folderNode == null) {
@@ -219,11 +194,8 @@ class ChangeManager implements DomainFolderChangeListener {
 			return null; // not visited 
 		}
 
-		GTreeNode child = folderNode.getChild(domainFile.getName());
+		return (DomainFileNode) folderNode.getChild(domainFile.getName(),
-		if (child instanceof DomainFileNode) {
+			n -> (n instanceof DomainFileNode));
-			return (DomainFileNode) child;
-		}
-		return null;
 	}
 
 	private void updateFolderNode(DomainFolder parent) {

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/CheckInTask.java

@@ -58,7 +58,7 @@ public class CheckInTask extends VersionControlTask implements CheckinHandler {
 				throw new CancelledException();
 			}
 			if (actionID != VersionControlDialog.APPLY_TO_ALL) {
-				showDialog(false, df.getName()); // false==> checking in vs. 
+				showDialog(false, df.getName(), df.isLinkFile()); // false==> checking in vs. 
 				// adding to version control
 				if (actionID == VersionControlDialog.CANCEL) {
 					monitor.cancel();

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/DomainFileNode.java

@@ -16,6 +16,7 @@
 package ghidra.framework.main.datatree;
 
 import java.io.IOException;
+import java.net.URL;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 
@@ -24,6 +25,8 @@ import javax.swing.SwingWorker;
 
 import docking.widgets.tree.GTreeNode;
 import generic.theme.GIcon;
+import ghidra.framework.data.FolderLinkContentHandler;
+import ghidra.framework.data.LinkHandler;
 import ghidra.framework.model.DomainFile;
 import ghidra.framework.store.ItemCheckoutStatus;
 import ghidra.util.*;
@@ -174,7 +177,7 @@ public class DomainFileNode extends GTreeNode implements Cuttable {
 		if (domainFile.isHijacked()) {
 			newDisplayName += " (hijacked)";
 		}
-		else if (domainFile.isVersioned()) {
+		else if (domainFile.isVersioned() && !domainFile.isLinkFile()) {
 			int versionNumber = domainFile.getVersion();
 			String versionStr = "" + versionNumber;
 
@@ -208,20 +211,34 @@ public class DomainFileNode extends GTreeNode implements Cuttable {
 	}
 
 	private void setToolTipText() {
-		String newToolTipText = toolTipText;
+		String newToolTipText = null;
 		if (domainFile.isInWritableProject() && domainFile.isHijacked()) {
 			newToolTipText = "Hijacked file should be deleted or renamed";
 		}
 		else {
+			StringBuilder buf = new StringBuilder();
+			try {
+				if (domainFile.isLinkFile()) {
+					URL url = LinkHandler.getURL(domainFile);
+					buf.append("URL: ");
+					buf.append(StringUtilities.trimMiddle(url.toString(), 120));
+					newToolTipText = buf.toString();
+				}
+			}
+			catch (IOException e1) {
+				// ignore
+			}
+			if (newToolTipText == null) {
 				long lastModified = domainFile.getLastModifiedTime();
 				newToolTipText = "Last Modified " + formatter.format(new Date(lastModified));
+			}
 			if (domainFile.isCheckedOut()) {
 				try {
 					ItemCheckoutStatus status = domainFile.getCheckoutStatus();
 					if (status != null) {
-						newToolTipText = HTMLUtilities.toHTML(
+						newToolTipText = "Checked out " +
-							"Checked out " + formatter.format(new Date(status.getCheckoutTime())) +
+							formatter.format(new Date(status.getCheckoutTime())) +
-								";\n" + newToolTipText);
+							"\n" + newToolTipText;
 					}
 				}
 				catch (IOException e) {
@@ -232,6 +249,7 @@ public class DomainFileNode extends GTreeNode implements Cuttable {
 			if (domainFile.isReadOnly()) {
 				newToolTipText += " (read only)";
 			}
+			newToolTipText = HTMLUtilities.toLiteralHTML(newToolTipText, 0);
 		}
 		toolTipText = newToolTipText;
 	}
@@ -243,11 +261,37 @@ public class DomainFileNode extends GTreeNode implements Cuttable {
 
 	@Override
 	public int compareTo(GTreeNode node) {
+		// Goal is to sort folder link-files similar to a folder
 		if (node instanceof DomainFolderNode) {
+			if (isFolderLink()) {
+				int c = super.compareTo(node);
+				if (c != 0) {
+					// A link-file name is permitted to match another folder node but
+					// should not be considered equal
+					return c;
+				}
+			}
 			return 1;
 		}
+		if (node instanceof DomainFileNode) {
+			DomainFileNode otherFileNode = (DomainFileNode) node;
+			if (isFolderLink()) {
+				if (otherFileNode.isFolderLink()) {
 					return super.compareTo(node);
 				}
+				return -1;
+			}
+			else if (otherFileNode.isFolderLink()) {
+				return 1;
+			}
+		}
+		return super.compareTo(node);
+	}
+
+	boolean isFolderLink() {
+		return FolderLinkContentHandler.FOLDER_LINK_CONTENT_TYPE
+				.equals(domainFile.getContentType());
+	}
 
 	@Override
 	public void valueChanged(Object newValue) {

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/DomainFolderNode.java

@@ -22,20 +22,18 @@ import javax.swing.Icon;
 
 import docking.widgets.tree.GTreeLazyNode;
 import docking.widgets.tree.GTreeNode;
-import generic.theme.GIcon;
 import ghidra.framework.model.*;
-import ghidra.util.InvalidNameException;
+import ghidra.util.*;
-import ghidra.util.Msg;
 import resources.ResourceManager;
 
 /**
  * Class to represent a node in the Data tree.
  */
 public class DomainFolderNode extends GTreeLazyNode implements Cuttable {
-	private static final Icon ENABLED_OPEN_FOLDER =
+
-		new GIcon("icon.datatree.node.domain.folder.open");
+	private static final Icon ENABLED_OPEN_FOLDER = DomainFolder.OPEN_FOLDER_ICON;
-	private static final Icon ENABLED_CLOSED_FOLDER =
+	private static final Icon ENABLED_CLOSED_FOLDER = DomainFolder.CLOSED_FOLDER_ICON;
-		new GIcon("icon.datatree.node.domain.folder.closed");
+
 	private static final Icon DISABLED_OPEN_FOLDER =
 		ResourceManager.getDisabledIcon(ENABLED_OPEN_FOLDER);
 	private static final Icon DISABLED_CLOSED_FOLDER =
@@ -55,11 +53,18 @@ public class DomainFolderNode extends GTreeLazyNode implements Cuttable {
 
 		// TODO: how can the folder be null?...doesn't really make sense...I don't think it ever is
 		if (domainFolder != null) {
-			toolTipText = domainFolder.getPathname();
+			toolTipText = StringUtilities.trimMiddle(domainFolder.getPathname(), 120);
+			toolTipText = HTMLUtilities.toLiteralHTML(toolTipText, 0);
 			isEditable = domainFolder.isInWritableProject();
 		}
 	}
 
+	@Override
+	public boolean isAutoExpandPermitted() {
+		// Prevent auto-expansion through linked-folders
+		return !domainFolder.isLinked();
+	}
+
 	/**
 	 * Get the domain folder; returns null if this node represents a domain file.
 	 *
@@ -96,6 +101,10 @@ public class DomainFolderNode extends GTreeLazyNode implements Cuttable {
 
 	@Override
 	public Icon getIcon(boolean expanded) {
+		if (domainFolder instanceof LinkedDomainFolder) {
+			// NOTE: cut operation not supported
+			return ((LinkedDomainFolder) domainFolder).getIcon(expanded);
+		}
 		if (expanded) {
 			return isCut ? DISABLED_OPEN_FOLDER : ENABLED_OPEN_FOLDER;
 		}
@@ -119,8 +128,12 @@ public class DomainFolderNode extends GTreeLazyNode implements Cuttable {
 
 	@Override
 	protected List<GTreeNode> generateChildren() {
+
 		List<GTreeNode> children = new ArrayList<>();
-		if (domainFolder != null) {
+		if (domainFolder != null && !domainFolder.isEmpty()) {
+
+			// NOTE: isEmpty() is used to avoid multiple failed connection attempts on this folder
+
 			DomainFolder[] folders = domainFolder.getFolders();
 			for (DomainFolder folder : folders) {
 				children.add(new DomainFolderNode(folder, filter));
@@ -128,6 +141,13 @@ public class DomainFolderNode extends GTreeLazyNode implements Cuttable {
 
 			DomainFile[] files = domainFolder.getFiles();
 			for (DomainFile domainFile : files) {
+				if (domainFile.isLinkFile() && filter != null && filter.followLinkedFolders()) {
+					DomainFolder folder = domainFile.followLink();
+					if (folder != null) {
+						children.add(new DomainFolderNode(folder, filter));
+						continue;
+					}
+				}
 				if (filter == null || filter.accept(domainFile)) {
 					children.add(new DomainFileNode(domainFile));
 				}
@@ -173,7 +193,8 @@ public class DomainFolderNode extends GTreeLazyNode implements Cuttable {
 	@Override
 	public int compareTo(GTreeNode node) {
 		if (node instanceof DomainFileNode) {
-			return -1;
+			// defer to DomainFileNode for comparison
+			return -((DomainFileNode) node).compareTo(this);
 		}
 		return super.compareTo(node);
 	}

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/ProjectDataTreePanel.java

@@ -423,6 +423,9 @@ public class ProjectDataTreePanel extends JPanel {
 		root = createRootNode(projectName);
 
 		tree = new DataTree(tool, root);
+		if (!isActiveProject) {
+			tree.setName(tree.getName() + ": " + projectName);
+		}
 
 		if (plugin != null) {
 			tree.addGTreeSelectionListener(e -> {

Ghidra/Framework/Project/src/main/java/ghidra/framework/main/datatree/VersionControlDialog.java

@@ -117,12 +117,6 @@ public class VersionControlDialog extends DialogComponentProvider {
 		return keepFileCB.isSelected();
 	}
 
-	void setCreateKeepFile(boolean selected) {
-		if (!addToVersionControl) {
-			keepFileCB.setSelected(selected);
-		}
-	}
-
 	/**
 	 * Return the comments for the add to version control.
 	 * @return may be the empty string
@@ -133,10 +127,14 @@ public class VersionControlDialog extends DialogComponentProvider {
 
 	/*
 	 * Disable the check box for "keep checked out" because some files are still in use. 
+	 * @param enabled true if checkbox control should be enabled, false if disabled
+	 * @param selected true if default state should be selected, else not-selected
+	 * @param disabledMsg tooltip message if enabled is false, otherwise ignored.
 	 */
-	public void setKeepCheckboxEnabled(boolean enabled) {
+	public void setKeepCheckboxEnabled(boolean enabled, boolean selected, String disabledMsg) {
 		keepCB.setEnabled(enabled);
-		keepCB.setToolTipText(enabled ? "" : "Must keep Checked Out because the file is in use");
+		keepCB.setSelected(selected);
+		keepCB.setToolTipText(enabled ? "" : disabledMsg);
 	}
 
 	private JPanel buildMainPanel() {