300245 - Failure to repaint XUL <listitem>s on mousewheel scroll.

Status: VERIFIED FIXED

(Core :: XUL, defect)

Description

[Stephen Donner [:stephend] Not actively reading bugmail]

Build ID: 2005-07-09-06 Windows XP SeaMonkey trunk.

Summary: Failure to repaint XUL <listitem>s on mousewheel scroll.

Steps to Reproduce:

1. Edit -> Preferenced -> Advanced -> System
2. Scroll the <listitem>s for "Windows should use SeaMonkey to open these file
types:" to the very bottom.
3. Using your mousewheel (with default scroll setting which seems to be 1 line),
scroll up.
4. If step #3, doesn't do this, keep repeating, and eventually you'll see the
lack of paint.

Comment 1

[Stephen Donner [:stephend] Not actively reading bugmail]

Attachment: Screenshot

I've found the easiest (or perhaps only) way to reproduce this bug is to
uncheck some of the boxes near the top (try half), scroll to the bottom, and
then use the mousewheel.  It's almost 100% reproducible from there.

Comment 2

[[e-mail]]

Actually I see it scrolling both down and up.
When the bug occurs, there are several effects:
1. The top two rows don't appear to be painted
2. Further mousewheeling up will then paint those rows
3. Pressing the up scrollbarbutton has no effect
4. Pressing the down scrollbarbutton scrolls three lines
It's as if the listbox and scrollbar are out of sync.

Comment 3

[[e-mail]]

Attachment: Proposed patch

The built-in scrolling conflicts with the listbox's scroll event handler.

Comment 4

[[e-mail]]

Fix checked in.

Comment 5

[Stephen Donner [:stephend] Not actively reading bugmail]

Verified FIXED using build 2005-07-15-05 on Windows XP SeaMonkey trunk.