498593 - Scrollbars are behaving strange

Status: RESOLVED FIXED

(Core :: Layout, defect, P2)

Description

[joggink]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2a1pre) Gecko/20090614 Minefield/3.6a1pre
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2a1pre) Gecko/20090614 Minefield/3.6a1pre

When scrolling down with my scrollwheel, the position of the scrollbar seems to be positioned wrong. I can scroll down the entire page, but my scrollbar is going in overflow.

Reproducible: Couldn't Reproduce

Steps to Reproduce:
1. Visit the link above
2. Scroll down
Actual Results:  
When I refreshed the scrollbar worked normal again..

Expected Results:  
After the refresh the scrollbar was positioned in a correct relation to the scrolltop position of the page

Comment 1

[Stefano]

It works fine when I tried.

Comment 2

[joggink]

I can't duplicate it anymore, should have taken a screencast, it was strange. thought at first it had something to do with the css interpretation.

Comment 3

[Ria Klaassen (not reading all bugmail)]

This works fine for me with Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.2a1pre) Gecko/20090615 Minefield/3.6a1pre

Can you also reproduce this in safe-mode? http://support.mozilla.com/en-US/kb/Safe+Mode

Comment 4

[Michael Ryan]

I've been seeing on a number of websites in some of the recent trunk nightlies on Windows XP. I'll try to get some STR and a regression window.

Comment 5

[Heather Arthur [:harth]]

I'm seeing this odd behavior too, I don't think it's trivial at all. When it happens, the size of scrollbar grabber is not correct, usually bigger than it should be, so when you scroll by dragging the grabber, you can't get to the bottom of the page. Scrolling using the middle mouse wheel does however get to the bottom of the page, but the visuals don't match up as the grabber hits the end of the scrollbar before you stop scrolling with the wheel.

I also can't reproduce this, but it happens with significant frequency.

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20090616 Minefield/3.6a1pre

Comment 6

[Dan Schafer [:dschafer]]

Attachment: Screenshot showing incorrect scrollbar

By closing all Minefield windows, then clicking on a link to this bug, I was able to consistently reproduce this issue.  I've attached a screenshot.

Comment 7

[Dan Schafer [:dschafer]]

Comment on attachment 383852 [details]
Screenshot showing incorrect scrollbar

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2a1pre) Gecko/20090617 Minefield/3.6a1pre

Comment 8

[Michael Ryan]

Reproduced with Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090613 Minefield/3.6a1pre after about 30 minutes of browsing.

Comment 9

[Michael Ryan]

I'm going to guess that this was caused by bug 492837. That would fit into the general timeframe of when this broke.

Comment 10

[Michael Ryan]

Good?: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090611 Minefield/3.6a1pre
Bad: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090612 Minefield/3.6a1pre

http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=4430cae50dad&tochange=860a9acc39b1

Comment 11

[Michael Ryan]

Good?: http://hg.mozilla.org/mozilla-central/rev/9eed09531a50
Bad: http://hg.mozilla.org/mozilla-central/rev/af7c59f1634a

So it's bug 492837. Still don't have any STR, though.

Comment 12

[Michael Ryan]

Changing summary to reflect that this can also occur with horizontal scrollbars.

Comment 14

[Matthew Gregan [:kinetik]]

There's a standalone testcase attached to bug 498257 that reproduces this on every load (assuming the window is small enough that a scrollbar is needed).

Comment 15

[(not currently active) Ted Mielczarek]

I've seen this a few times on Windows trunk nightlies. Currently I have a bugzilla attachment edit page open, where the patch viewer iframe's scrollbar thinks the document is much shorter than it actually is.

Comment 16

[Boris Zbarsky [:bzbarsky]]

roc, do we end up not setting up the callback on the next time through or something?

Comment 17

[Martijn Wargers (dead)]

Probably the same issue as bug 499307.

Comment 18

[Michael Ryan]

Confirming that bug 498257 was fixed by the patch for bug 478465. That's probably enough to assume that this was fixed, too.

Comment 19

[Michael Ryan]

After some heavy usage of builds before and after the checkin for bug 478465, I think I can call this one fixed.

Comment 20

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

Mass change: adding fixed1.9.2 keyword

(This bug was identified as a mozilla1.9.2 blocker which was fixed before the mozilla-1.9.2 repository was branched (August 13th, 2009) as per this query: http://is.gd/2ydcb - if this bug is not actually fixed on mozilla1.9.2, please remove the keyword. Apologies for the bugspam)