254340 - form select options list scrolls double on mouse click on scroll bar

Status: RESOLVED FIXED

(SeaMonkey :: General, defect)

Description

[John B. Sandlin]

User-Agent:       Mozilla/5.0 (OS/2; U; Warp 4.5; en-US; rv:1.8a2) Gecko/20040719
Build Identifier: Mozilla/5.0 (OS/2; U; Warp 4.5; en-US; rv:1.8a2) Gecko/20040719

On the form select drop down list of options, when I mouse click on the arrow
head it scrolls two options, when I click in the scroll area it scrolls two
pages.  This has been an issue in the last several releases of mozilla.  My
machine is an IBM PC300PL with S3 Trio video and an IBM 800dpi scroll point
optical mouse running OS/2 Warp 4 fix pack 15 (latest free release).

Reproducible: Always
Steps to Reproduce:
1. Open www.comics.com
2. open "Select a feature" form select box
3. click scroll bar

Actual Results:  
The list of options scrolls twice the desired distance

Expected Results:  
On clicking the arrow head on the scroll bar one option list should
advance/retreat on item, clicking in the scroll bar area should scroll the list
one page of options.

This occurs with the default theme, and has been a problem since at least
release 1.6.

Comment 1

[John B. Sandlin]

Attachment: Simplified test case - plain form/select with options.

The only action of this html is to display the form select options.  On my OS/2
Warp 4 using mozilla 1.8a2 it demonstrates the bug every time.

Comment 2

[Boris Zbarsky [:bzbarsky]]

Sounds like an OS/2 only issue... I'm not seeing this on Linux.

Comment 3

[Mike Kaply [:mkaply]]

Strange. Definitely OS/2 only.

Do you know if this has ever worked?

Comment 4

[Mike Kaply [:mkaply]]

Very odd. In the drop down case, we are getting two WM_BUTTON1DOWNs from the
operating system, one posted and one sent.

In other cases in Mozilla, we don't get two.

Comment 5

[Peter Weilbacher]

Seems to be independent of mouse driver and OS/2 version. I get the same
behaviour with AMouse and a Logitech Optical mouse on eCS 1.1. In the testcase,
and on this bugzilla page.
Mozilla/5.0 (OS/2; U; Warp 4.5; en-US; rv:1.8a3) Gecko/20040802
Mozilla/5.0 (OS/2; U; Warp 4.5; en-US; rv:1.7) Gecko/20040618
Mozilla/5.0 (OS/2; U; Warp 4.5; en-US; rv:1.7) Gecko/20040629 Firefox/0.9.1

Comment 6

[Mike Kaply [:mkaply]]

This has been around forever.

The way to fix it appears to be to do a WinSetActiveWindow to mWnd in the
BUTTON1DOWN and then set the return to TRUE so we don't call the default Window
procedure - the default window procedure is sending the message.

In the process of looking at this, I also found that we have a another bug
dragging scrollbars - it appears to have regressed between May 8 and May 18.

Comment 7

[Mike Kaply [:mkaply]]

Attachment: Fix for problem

Don't let the default window proc handle the button 1 down - just do the
WinSetActiveWindow ourselves.

Note the other problem with dragging the thumb is unrelated.

Comment 8

[Mike Kaply [:mkaply]]

Patch checked in everywhere.