506503 - Firefox 3.5 hangs on large forms

Status: VERIFIED DUPLICATE of bug 477564

(Firefox :: Session Restore, defect)

Description

[shaunkii]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.1) Gecko/20090715 Firefox/3.5.1 (.NET CLR 3.5.30729)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1.1) Gecko/20090715 Firefox/3.5.1 (.NET CLR 3.5.30729)

[taken from: http://forums.mozillazine.org/viewtopic.php?f=38&t=1361585]

I've found that Firefox 3.5 reliably hangs a few seconds after loading a page that contains a very large form. I've verified that there are not multiple sessionstore.js files in the profile. Firefox 3.0.11, IE7, IE8, and Safari do not have this problem. What happens is that Firefox hangs; the OS reports it as "not responding"; if you leave it, eventually it begins to respond again (this took about 6 minutes for the 3000+ checkbox form I was viewing); but freezes again once you've typed a few characters into the form or clicked a few checkboxes. The same form worked flawlessly with Firefox 3.0.11, IE7 and IE8, and Safari 4.

I suspect that this problem may have to do with changes made in the session restoration function in 3.5. I think that FF 3.5 is trying to save the state on this very large form, and it's taking so long that the browser simply times out.

[taken from: http://forums.mozillazine.org/viewtopic.php?f=38&t=1361585]

--

I myself tried setting browser.sessionstore.interval to 20000 and found out that the browser started hanging after intervals of 20 seconds instead of the default 10, so it does look like a sessionstore problem. 

Reproducible: Always

Steps to Reproduce:
1. Open about:config
2. Change browser.sessionstore.interval to 1
3. Open a page with a large form, such as: http://shaunkii.110mb.com/hangTest.html
4. Click on a couple of radio buttons
Actual Results:  
Browser hangs and doesn't respond for a certain amount of time

Expected Results:  
Browser doesn't hang and everything is normal