Use special case for indexing empty files

src/index/mimetype.cpp

@@ -133,6 +133,9 @@ string mimetype(const string &fn, const struct stat *stp,
 	    return "inode/symlink";
 	if (!S_ISREG(stp->st_mode))
 	    return "inode/x-fsspecial";
+	// Empty files are just this: avoid further errors with actual filters.
+	if (stp->st_size == 0) 
+	    return "inode/x-empty";
     }
 
     string mtype;

src/sampleconf/mimeconf

@@ -133,6 +133,7 @@ image/vnd.djvu = exec rcldjvu
 image/svg+xml = exec rclsvg
 image/x-xcf = execm rclimg
 inode/symlink = internal
+inode/x-empty = exec rclnull
 message/rfc822 = internal
 text/calendar = execm rclics;mimetype=text/plain
 text/html  = internal