731567 - Tearing 2 tabs then merging one of them leaks chrome://browser/content/browser.xul

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Loic]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20120228 Firefox/13.0a1
Build ID: 20120228031102

Steps to reproduce:

STR:

0) Start a new profile with Nightly
1) Install the add-on about:ccdump to hunt the leak:
https://addons.mozilla.org/en-US/firefox/addon/cycle-collector-analyzer/
2) Open a 1st tab and go to about:ccdump
3) Open a 2nd tab (and go to http://www.nytimes.com/ e.g.)
4) Open a 3rd tab (and go to http://www.latimes.com/ e.g.)
5) Tear the 2nd tab
6) Tear the 3rd tab
NB: at this step, you have 3 windows (about:ccdump, nytimes.com and latimes.com)
7) Grab the tab of the 2nd window (nytimes.com) and drop it on the left/right of the tab of the 3rd window (latimes.com)
8) Close the resulting window (confirm close if necessary)
9) Go back to tab about:ccdump, Run CC Analysis and search for nsDocument

Results:
nsDocument normal (XUL) chrome://browser/content/browser.xul leaks.
Root objects:
root nsNodeInfoManager
root XPCVariant

At step #7, you can grab the tab of the 2nd window and merge it with the 1st window and closing the 3rd window, same result.
Idem with the 3rd window.

Comment 1

[Olli Pettay [:smaug][[e-mail]]]

browser.xul was in the cc log for some time, but then disappeared.
Did you run CC several times?

Comment 2

[Loic]

Yes, I ran CC several times. In addition, 'Run CC Analysis' in about:ccdump runs Firefox CC three times to clean up garbage.

Comment 3

[Robert Claypool]

What is "tearing" a tab?

Comment 4

[Loic]

Tab tearing allows you to pull any tab out of your Firefox window into a completely new window or pull any tab into another window.

Comment 5

[Loic]

Did someone try to reproduce it?

Comment 6

[Andrew McCreight [:mccr8]]

Sorry, I've forgotten to look at this. We marked it P3 because this seems like an uncommon operation.

Comment 7

[Andrew McCreight [:mccr8]]

This doesn't reproduce for me any more.

Comment 8

[Nicholas Nethercote [inactive]]

Loic, can you still reproduce?

Comment 9

[Loic]

(In reply to Nicholas Nethercote [:njn] from comment #8)
> Loic, can you still reproduce?

No. I guess you can close it.

Comment 10

[Andrew McCreight [:mccr8]]

Thanks for looking.