Multiple tabs close when clicking tab close button; Multiple click events on element destruction




12 years ago
12 years ago


(Reporter: zzxc, Unassigned)


2.0 Branch

Firefox Tracking Flags

(Not tracked)



(1 attachment)



12 years ago
User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1b2) Gecko/20060829 BonEcho/2.0b2
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1b2) Gecko/20060829 BonEcho/2.0b2

Rarely, when closing a tab, more than one tab closes.  This only occurs when the tab that is supposed to close is delayed in closing (eg. when too many tabs are loaded and the browser is running slow) and when the mouse stays hovered over the tab close button.  I have verified this in various nightly builds, including the Firefox 2 Beta 2 release.  On Firefox 2 Beta 2 Test Day, I was able to get two other people - one on Windows XP and one on Mac OS X - to duplicate the problem.  I have been able to duplicate the problem with other self-destruct-on-click XUL or HTML elements.  See the attached html file for a row of self destructing buttons.  It is possible to, on the row of buttons, close multiple "tabs" upon lifting the mouse button.

Reproducible: Sometimes

Steps to Reproduce:
1. Open many tabs, preferably with as much flash animation and javascript as possible to slow things down.  40 tabs should be enough.  
2. After much normal browsing, go to the last tab.  Scroll around and use javascript applications. The most successful thing I've done to reproduce it is matching images on
3.Click and hold the mouse button down on the tab's "close tab" button.  Hold the button down for at least a couple seconds.
4. Quickly release the mouse button without moving the mouse.  Make sure the mouse stays over the tab close button.  With enough tabs open, the tab close button for the next tab will position itself under your mouse.  Rarely, the next tab will close as well.  I have had as many as three tabs close at once.
Actual Results:  
Two tabs close upon release of the mouse button.  Note that the second tab to close is brought to focus before being destroyed.

Expected Results:  
Only one tab closes.  The next tab is brought into focus.

I have tabminwidth set to 40px, though others have confirmed it without this setting.

Note that manually closing tabs with a javascript console does not result in this behavior, ever.  It is specific to the mouse event handling.

I have confirmed this on a clean install of Firefox 2 Beta 2 with no extensions, themes, or other XUL or XUL bindings.

I have found newsgroup postings of people experiencing similar problems in firefox.  They are:*&rnum=4#21570360de8bd35f*&rnum=12#b4d808cbaa2d133e

Related bugs that may be caused by the same problem:
bug 238236
bug 348200

A solution to this problem may be to disable clicks for 10 milliseconds or so after a clicked on element is destroyed.  The elements that are not supposed to be destroyed properly receive click events and act on them.  A better solution would, obviously, be to fix the underlaying problem.

Comment 1

12 years ago
Created attachment 236856 [details]
Self destructing element example


12 years ago
Version: unspecified → 2.0 Branch


12 years ago
Summary: Multiple tabs close when clicking tab close button → Multiple tabs close when clicking tab close button; Multiple click events on element destruction

Comment 2

12 years ago
I believe I found a repeatable case of this (or something like it). With the current Firefox 2.0 RC2, visit:

click "Add this job to Cart" and then do <cntrl>W or click the "Close tab" button and poof! Firefox closes.

Comment 3

12 years ago
Marking WFM.  I haven't seen this bug for a long time, and Firefox 2 shipped long ago.
Last Resolved: 12 years ago
Resolution: --- → WORKSFORME
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