591650 - Closing tabs does not always eliminate the tab, either visually or in memory.

Status: RESOLVED DUPLICATE of bug 585785

(Firefox :: Tabbed Browser, defect)

Description

[Luke S]

User-Agent:       Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b4) Gecko/20100818 Firefox/4.0b4
Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b4) Gecko/20100818 Firefox/4.0b4

In the latest beta (I think it didn't appear before 4.0b4), when you close a tab it now performs the unusual animation of rapidly "shrinking/sliding" the tab into the previous one. That's okay, except that sometimes it gets stuck.

See the URL for this specific instance.
In this case, I closed a tab named "Cisco SR2016 expert reviews", and it did the close tab animation, but left the favicon hanging between two other tabs... This is still counted as a tab. It has a name, it can be switched to, it can be saved in add-ons like Session Manager, and memory usage appeared to be the same after closing... I don't know why it didn't complete the tab-closing process, but anyway, there you have it.

Problem may be caused by add-on "Tab X" which was fully compatible with the beta thus far, but maybe something has been slightly changed with tabs that rendered it incompatible.

Reproducible: Sometimes

Steps to Reproduce:
1. Open a lot of tabs, particularly ones with favicon data.
2. Close various tabs rapidly.
3. If it doesn't work, install Add-On Compatibility Reporter, and then Tab X, enable Tab X, and try again.
Actual Results:  
Tab remained in limbo, neither living nor dead

Expected Results:  
Tab should have been closed

Using custom theme, but the problem isn't really related to graphical glitches.

Comment 2

[Luke S]

Whoops! Sorry for creating a duplicate; you must admit that to a non-code-insider, the title of the other thread would be difficult to recognize as the same issue :) Anyway, this can serve as another confirmation to it...