517176 - Switching away from the Get Add-ons pane while it is loading thumbnails causes multiple getElementById errors

Status: RESOLVED FIXED

(Toolkit :: Add-ons Manager, defect)

Description

[Dave Townsend [:mossop]]

Attachment: patch rev 1

The Get Add-ons pane does some background loading of thumbnails for the results so it knows how big to size them in the UI. If you switch away from the pane before the load is complete then the listener monitoring it throws some errors like:

Error: document.getElementById(id) is null
Source File: chrome://mozapps/content/extensions/extensions.xml
Line: 415

Patch is pretty simple, just check the element is still in the document.

Comment 1

[Robert Strong (they/them - no direct email)]

Comment on attachment 401179 [details] [diff] [review]
patch rev 1

>diff --git a/toolkit/mozapps/extensions/content/extensions.xml b/toolkit/mozapps/extensions/content/extensions.xml
>--- a/toolkit/mozapps/extensions/content/extensions.xml
>+++ b/toolkit/mozapps/extensions/content/extensions.xml
>@@ -451,20 +451,26 @@
>         if (this.hasAttribute("thumbwidth")) {
>           this._displayImage();
>           return;
>         }
> 
>         var image = new Image();
>         var id = this.id;
>         image.onload = function() {
>-          document.getElementById(id)._imageLoaded(image);
>+          var self = document.getElementById(id);
>+          // This element might have gone away in the meantime
>+          if (self)
>+            self._imageLoaded(image);
>         };
>         image.onerror = function() {
>-          document.getElementById(id)._hideImage();
>+          var self = document.getElementById(id);
>+          // This element might have gone away in the meantime
>+          if (self)
>+            self.._hideImage();
Should probably fix this ^

Comment 2

[Dave Townsend [:mossop]]

Attachment: patch rev 2

Yeah let's try that again.

Comment 3

[Dave Townsend [:mossop]]

http://hg.mozilla.org/mozilla-central/rev/42a5cbc5c289

Comment 4

[Dave Townsend [:mossop]]

Comment on attachment 401195 [details] [diff] [review]
patch rev 2

This is a simple patch that cleans up a few errors in the error console, no risk.

Comment 5

[Dave Townsend [:mossop]]

Landed on branch: http://hg.mozilla.org/releases/mozilla-1.9.2/rev/dc5b45bbdafc