From 869c4de289b37517cfb01180ba669118db6c3fb4 Mon Sep 17 00:00:00 2001
From: Jonas <Snuffleupagus@server.fake>
Date: Tue, 23 Jul 2013 02:00:37 +0200
Subject: [PATCH] [PDFHistory] Prevent the history from getting stuck in
certain edge cases
---
web/pdf_history.js | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/web/pdf_history.js b/web/pdf_history.js
index ee00c6b3b..60bcab401 100644
--- a/web/pdf_history.js
+++ b/web/pdf_history.js
@@ -231,6 +231,22 @@ var PDFHistory = {
beforeUnload) {
if (!(this.currentBookmark && this.currentPage)) {
return null;
+ } else if (this.updatePreviousBookmark) {
+ this.updatePreviousBookmark = false;
+ }
+ if (this.uid > 0 && !(this.previousBookmark && this.previousPage)) {
+ // Prevent the history from getting stuck in the current state,
+ // effectively preventing the user from going back/forward in the history.
+ //
+ // This happens if the current position in the document didn't change when
+ // the history was previously updated. The reasons for this are either:
+ // 1. The current zoom value is such that the document does not need to,
+ // or cannot, be scrolled to display the destination.
+ // 2. The previous destination is broken, and doesn't actally point to a
+ // position within the document.
+ // (This is either due to a bad PDF generator, or the user making a
+ // mistake when entering a destination in the hash parameters.)
+ return null;
}
if ((!this.current.dest && !onlyCheckPage) || beforeUnload) {
if (this.previousBookmark === this.currentBookmark) {
@@ -265,7 +281,8 @@ var PDFHistory = {
if (addPrevious && !overwrite) {
var previousParams = this._getPreviousParams();
if (previousParams) {
- var replacePrevious = (this.current.hash !== this.previousHash);
+ var replacePrevious = (!this.current.dest &&
+ this.current.hash !== this.previousHash);
this._pushToHistory(previousParams, false, replacePrevious);
}
}