347187 - extremely slow Javascript execution leaving browser unresponsive

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Dick Streefland]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.5) Gecko/20060626 Firefox/1.5.0.5 (Debian-1.5.dfsg+1.5.0.5-1)
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.5) Gecko/20060626 Firefox/1.5.0.5 (Debian-1.5.dfsg+1.5.0.5-1)

The page at http://nl.maps.fon.com/ takes more than a minute to load. During this time, the user interface is completely unresponsive. The same page only takes a couple of seconds with Mozilla 1.7.12 (Gecko/20060607).

I think there are actually two problems here:
1) A regression causing a massive Javascript slowdown.
2) The fact that the user interface is unresponsive when the script runs.

Reproducible: Always

Steps to Reproduce:
1. Visit http://nl.maps.fon.com/

Actual Results:  
Firefox is "dead" for more than a minute.

Expected Results:  
The Javascript code should run faster, and the user interface should not be blocked when the script runs.

I have the following extensions installed:
- User Agent Switcher 0.6.8
- Gcache 0.2.3
- MozEX 1.0.7
- Adblock v.5 d3 nightly 42
When I visit the URL with all extensions disabled, I get a popup message about an "unresponsive script" every 10 seconds or so. Apparently, one of the extensions blocks these messages.

Comment 1

[Ria Klaassen (not reading all bugmail)]

Yeah, I see also that slow script warning on Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5.0.6
I don't see it in the latest branch builds and that's probably because 1.5.0.6 has a lower value for dom.max_script_run_time than branch. 
When I change the value to 10 like in branch and trunk, the message stays away and the site loads normally.

Comment 2

[Wladimir Palant]

I don't see the problem in Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/1.5.0.6, it only takes a few seconds. Maybe it is an extension problem? Reporter, please try deactivating your extensions in the Extension Manager to see whether any of them is causing the problem (Adblock being the most likely candidate).

Comment 3

[Dick Streefland]

As I wrote in my initial report, the problem persists when I disable all extensions. Just to be sure, I installed Firefox 1.5.0.6 (Gecko/20060728), and tried that in the default configuration, by moving my ~/.mozilla directory out of the way. I have to click 7 times on the Continue button of the "Unresponsive script" popup before the script finishes, so the problem is still there.

Mozilla 1.7.13 (Gecko/20060620) in the default configuration loads the page in a couple of seconds.

Comment 4

[Wladimir Palant]

Sorry, I overlooked this part. Tried it in Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.6) Gecko/20060728 SUSE/1.5.0.6-0.1 Firefox/1.5.0.6 - the page takes a few seconds to load but still nothing extraordinary.

Comment 5

[Steve England [:stevee]]

Reporter, do you still see this problem with Firefox 2.0? If not, can you please close this bug as WORKSFORME. Thanks!

Comment 6

[Dick Streefland]

The example URL is gone, so I can't test it anymore. I haven't encountered similar problems lately, so let's assume the problem is fixed.