From 624c9e823b5163e2754a71655a2e37f8bb5c04a0 Mon Sep 17 00:00:00 2001
From: Bala Clark <balaclark@gmail.com>
Date: Thu, 8 Sep 2011 12:27:01 +0200
Subject: [PATCH] don't allow navigating to non-existant pages

---
 lib/ComicBook.js | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/ComicBook.js b/lib/ComicBook.js
index 5843497..b224f4d 100755
--- a/lib/ComicBook.js
+++ b/lib/ComicBook.js
@@ -92,8 +92,11 @@ function ComicBook(id, srcs, opts) {
 	var page_requested = false; // used to request non preloaded pages
 	var shiv = false;
 
+	// page hash on first load
+	var hash = parseInt(location.hash.substring(1),10) - 1;
+
 	// the current page, can pass a default as a url hash
-	var pointer = (parseInt(location.hash.substring(1),10) - 1) || 0;
+	var pointer = (hash < srcs.length) ? hash : 0;
 
 	/**
 	 * Gets the window.innerWidth - scrollbars
@@ -388,7 +391,7 @@ function ComicBook(id, srcs, opts) {
 	 */
 	ComicBook.prototype.getPage = function(i) {
 
-		if (i < 0 || i > srcs.length) {
+		if (i < 0 || i > srcs.length-1) {
 			throw ComicBookException.INVALID_PAGE+' '+i;
 		}
 
@@ -643,7 +646,13 @@ function ComicBook(id, srcs, opts) {
 	 */
 	ComicBook.prototype.drawNextPage = function () {
 
-		if (!this.getPage(pointer+1)) { return false; }
+		var page;
+
+		try {
+			page = this.getPage(pointer+1);
+		} catch (e) {}
+
+		if (!page) { return false; }
 
 		if (pointer + 1 < pages.length) {
 			pointer += (options.displayMode === "single" || is_double_page_spread) ? 1 : 2;
@@ -658,7 +667,12 @@ function ComicBook(id, srcs, opts) {
 	 */
 	ComicBook.prototype.drawPrevPage = function () {
 
-		var page = this.getPage(pointer-1);
+		var page;
+
+		try {
+			page = this.getPage(pointer-1);
+		} catch (e) {}
+
 		if (!page) { return false; }
 
 		is_double_page_spread = (page.width > page.height); // need to run double page check again here as we are going backwards