858643 - "TypeError: candidate is undefined" when closing tabs.

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser, defect)

Description

[Michael Kraft [:morac]]

Any time I close a tab using the "x" button on the tab in the latest nightly load, the following error appears in the error console:

Timestamp: 4/5/2013 12:56:33 PM
Error: TypeError: candidate is undefined
Source File: chrome://browser/content/tabbrowser.xml
Line: 4226


The code generating the error is:

          let candidate = visibleTabs[tabIndex - 1];
->        if (!candidate.selected) {



This started happening relatively recently.

Comment 1

[Tim Taubert [:ttaubert] (inactive)]

Attachment: don't handle mouseover event for closing tabs

Comment 2

[Tim Taubert [:ttaubert] (inactive)]

https://hg.mozilla.org/integration/fx-team/rev/04d0c8e895ce

Comment 3

[Tim Taubert [:ttaubert] (inactive)]

https://hg.mozilla.org/mozilla-central/rev/04d0c8e895ce

Comment 4

[Tim Taubert [:ttaubert] (inactive)]

Comment on attachment 736147 [details] [diff] [review]
don't handle mouseover event for closing tabs

[Approval Request Comment]
Bug caused by (feature/regressing bug #): bug 585558
User impact if declined: errors in the console when closing tabs
Testing completed (on m-c, etc.): 
Risk to taking this patch (and alternatives if risky): very low risk
String or IDL/UUID changes made by this patch: none

Comment 5

[Tim Taubert [:ttaubert] (inactive)]

https://hg.mozilla.org/releases/mozilla-aurora/rev/d017e30f54be

Comment 6

[Ioana (away)]

Verified as fixed on Windows 7 64bit, Mac OSX 10.7 and Ubuntu 13.04 32bit, using Firefox 22b2 (20130521223249). The error message in comment 0 is no longer displayed in the Error console when closing tabs.

Comment 7

[Ada [:adalucinet]]

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0
Mozilla/5.0 (X11; Linux x86_64; rv:23.0) Gecko/20100101 Firefox/23.0
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:23.0) Gecko/20100101 Firefox/23.0

Verified as fixed with Firefox 23 RC (Build ID: 20130730113002): the error message from comment 0 is not present in the Error console.