363291 - onmouseout is not called when leaving across the scrollbar on resized multi select fields

Status: RESOLVED INCOMPLETE

(Firefox :: General, defect)

Description

[sbyrne]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.7) Gecko/20060830 Firefox/1.5.0.7 (Debian-1.5.dfsg+1.5.0.7-2)
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.7) Gecko/20060830 Firefox/1.5.0.7 (Debian-1.5.dfsg+1.5.0.7-2)

If you have a multiple select field that has been resized (i.e. by javascript) such that the field originally did not show all of the options without scrolling, but now does, the onmouseout is not always called when the mouse leaves the field across the scrollbar at just the right speed. Onmouseout is always called when leaving across one of the other three edges of the select field. You have to go across the scrollbar with the mouse at just the right speed; if you go too fast or too slow, it works properly.

If you look closely, as you move the mouse over the scrollbar from the inside, it displays the position marker for a moment. It seems that if you get the mouse out during the brief moment that the position marker is shown, then onmouseout is not called.

I have reproduced this with the following (with official version from mozilla.com unless otherwise noted):
1.5.0.7 on Linux (Debian package)
2.0 on Linux
1.5.0.7 on Windows 2000 Server
2.0 on Windows 2000 Server
1.5.0.3 on Windows XP Professional
2.0 on Windows XP Professional

Reproducible: Sometimes

Steps to Reproduce:
1. Display a multi select field that scrolls.
2. Resize the field so it doesn't need to scroll anymore.
3. Move the mouse over the field.
4. Move the mouse out of the field over the scrollbar.

Actual Results:  
onmouseout was not called

Expected Results:  
onmouseout called

With the exception of "1.5.0.7 on Linux (Debian package)", all were with standard install, standard themes, no additional extensions installed.

Comment 1

[sbyrne]

Attachment: Example.

This is what is at http://www.sbyrne.org/~sbyrne/multiselectbug.html

Comment 2

[sbyrne]

I just noticed that I can only get this to happen if I am using the trackpad or trackpoing on my IBM (Lenovo) ThinkPad T43, not with a USB mouse.

I was running Windows inside a virual machine on top of Linux, so it is possible that there is a problem with the hardware or the pointing device driver. Nonetheless, it seems to me that the mouse started inside the box, and is now outside, so onmouseout still should have been called.

Comment 3

[Steve England [:stevee]]

Reporter, do you still see this problem with the latest Firefox 2? If not, can you please close this bug as WORKSFORME. Thanks!

Comment 4

[sbyrne]

I still see this behavior on Debian's Iceweasel 2.0.0.3, which is based on Firefox 2.something. I will check on an official Firefox build and report back soon.

Comment 5

[Steve England [:stevee]]

If it still happens with an official build, it'd be great if you could test with a trunk build too, since a lot of work in this area has gone on. Thanks!
- http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/

Comment 6

[u279076]

Due to lack of reporter feedback and the inability to reproduce this bug, it is
being resolved as INCOMPLETE.  Reporter, feel free to reopen this bug if you
still are experiencing this issue and wish to provide us with more information
so that we can help.