478699 - Firefox is randomly trying to fetch incorrect JavaScript file

Status: RESOLVED FIXED

(Core :: DOM: HTML Parser, defect, P2)

Description

[Paweł Kondzior]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20090210 Shiretoko/3.1b3pre
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.1b3pre) Gecko/20090210 Shiretoko/3.1b3pre

Firefox 3.1 is trying to fetch wrong url to javascript, like on the screenshot. It's totally random (url), and totally random appears.

Reproducible: Always

Steps to Reproduce:
1. Go to http://www.warhammer-online.pl/testcase.html
2. Open Firebug Net tab
3. Press few times shift+cmd+r to re-fetch site
4. Firefox will try to fetch  randomly number of weird urls like on attached screenshots


Expected Results:  
All urls should be fetched without 404 Not found error

All 404 not found errors on my daily work application are sent to my mailbox with full stack of application, i figured out that Fx 3.1 is producing all 404 Not Found errors with weird urls that are part of real urls from file that user is trying to view in browser. It seems that Fx 3.1 is randomly cutting random count of <script> urls. It depends probably on cache system.

Comment 1

[Paweł Kondzior]

Attachment: Sample screenshot

Comment 2

[Paweł Kondzior]

Attachment: Another sample with headers

Another sample that show Fx 3.1 trying to download
ttp://www.warhammer-online.pl /js/very_long_name_for_javascript_file_to_show_that_gecko_fails_31

which is wrong.

Comment 3

[Paweł Kondzior]

Attachment: Firefox 3.1 beta 2 screenshot

Reproducable in Fx 3.1 beta 2

Comment 4

[Paweł Kondzior]

Attachment: Fx 3.1 b2

Another example that shows this appears to be totally random.

Comment 5

[Mike Beltzner [:beltzner, not reading bugmail]]

Hey Pawel: can you find a regression range? See https://wiki.mozilla.org/Calendar:QA_Home#Finding_a_Regression_Range_on_a_Bug and http://db48x.net/regression-search/ for details.

--> Core::Networking:Cache, moving flag to blocking1.9.1?

Comment 6

[Paweł Kondzior]

Well i'm on that from 1 hour.

I've testes
Shiretoko alpha 1 - no regression
Shiretoko alpha 2 - no regression
Firefox 3.1 b1 - no regression
Firefox 3.1 b2 - regression appears

I recognized that between Fx 3.1 b1 and b2 Fx have new model of fetching files for pages, it's damn fast, so there is probably race somewhere

Comment 7

[Paweł Kondzior]

mac builds from http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2008/09/2008-09-29-02-mozilla-central/ are without regression
mac builds from http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2008/09/2008-09-30-02-mozilla-central/ are with regression

I thnik this is all related to speculative load of referenced files https://bugzilla.mozilla.org/show_bug.cgi?id=364315

Comment 8

[Paweł Kondzior]

build from 09-29 http://hg.mozilla.org/mozilla-central/rev/15cb5d25db05
build from 09-30 http://hg.mozilla.org/mozilla-central/rev/86b982e8b73e

Comment 9

[Paweł Kondzior]

Fx 3.1 b1 don't have regression because it was turned of 1 day before release
http://hg.mozilla.org/releases/mozilla-1.9.1/log/04218932d5b7/parser/htmlparser/src/nsParser.cpp

I think i can't do more to help here, I hope it will be fixed before 3.1 release. 
Cheers!

Comment 10

[Mike Beltzner [:beltzner, not reading bugmail]]

As per triage meeting, this blocks - needs someone to look into it. Blake?

Comment 11

[Blake Kaplan (:mrbkap) (inactive)]

Paweł, thanks for helping to track this down. It's an easy fix. The bug doesn't affect the actual rendering of the page, but it does send spurious requests that clutter up logs & the like (and waste cycles on mobile devices).

Comment 12

[Blake Kaplan (:mrbkap) (inactive)]

Attachment: CGI script used to test

I used this to test the fix. 'test.cgi' is a script that sleeps for 5 seconds before returning a valid JavaScript program. Before the patch that I'm about to attach, I see

[Tue Feb 17 14:05:49 2009] [error] [client 127.0.0.1] File does not exist: /home/mrbkap/public_html/SHOW_UP_IN_MY_LOGS, referer: http://localhost/~mrbkap/foo.cgi

in my error logs, and only one of:

[Tue Feb 17 14:23:15 2009] [error] [client 127.0.0.1] File does not exist: /home/mrbkap/public_html/SHOW_UP_IN_MY_LOGS_PASS, referer: http://localhost/~mrbkap/foo.cgi

with it.

Comment 13

[Blake Kaplan (:mrbkap) (inactive)]

Attachment: Fix

Without this line, the tokenizer would think that we're at the end of the document and return partial tokens to us.

Comment 14

[Johnny Stenback (:jst)]

Comment on attachment 362783 [details] [diff] [review]
Fix

Love it. r+sr=jst

Comment 15

[Blake Kaplan (:mrbkap) (inactive)]

http://hg.mozilla.org/mozilla-central/rev/79ef13e126a5 and http://hg.mozilla.org/releases/mozilla-1.9.1/rev/40818c0d61d3