553814 - scrollbar on xul listboxes (like the profile list in profile manager) disappears

Status: VERIFIED FIXED

(Core :: XUL, defect)

Description

[Timothy Nikkel (:tnikkel)]

If you have enough profiles to cause the profile list to be scrollable in the profile manager and then scroll it the scrollbar disappears sometimes.

The first bad changeset is http://hg.mozilla.org/mozilla-central/rev/a35c6813e87d (with the later build bustage fix applied), which is bug 544472.

Comment 1

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

I have a similar experience with the profile manager.

For me, if the profile list is scrolled to the top, there is no scrollbar visible.
If it gets scrolled down at all, the scrollbar appears.

The further down I scroll, the wider (not really sure what the descriptive word should be, there's more blank space on each side of the scrollbar) the scrollbar becomes.

Scrolling back towards the top of the list narrows the scrollbar, until you reach the top of the list and it disappears.

Comment 2

[Timothy Nikkel (:tnikkel)]

Yeah, that is the same thing I saw, I just described the most obvious problem. :)

Comment 3

[Alice0775 White]

Attachment: testcase

Comment 4

[Hermann Schwab]

It's seen in Minefield only, not in other current nightlies.
I tested it using zip builds:

Working:

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.3a4pre) Gecko/20100318 Minefield/3.7a4pre

http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2010-03-18-04-mozilla-central/

http://hg.mozilla.org/mozilla-central/rev/2cc5ad2cf917


Regressed:

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.3a4pre) Gecko/20100319 Minefield/3.7a4pre

http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/2010-03-19-04-mozilla-central/

http://hg.mozilla.org/mozilla-central/rev/5108c4c2c043

Comment 5

[Joe Drew (not getting mail)]

Won't block the release on this, but we'd take a patch.

Comment 6

[Timothy Nikkel (:tnikkel)]

This likely affects all listboxes, not just the profile manager.

Comment 7

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

(In reply to comment #6)
> This likely affects all listboxes, not just the profile manager.

It does, according to comment 3's attachment.

Comment 9

[fabi]

Vote for blocking - at least for our xulrunner based application it's a major issue.

Comment 10

[Neil Deakin]

Attachment: possible but somewhat untested patch

Fixes the problem for ordinary listboxes, but not tested for the profile manager.

Doesn't fix the underlying issue which is that a minimum height set on the listbox interferes with the real minimum height computation. I think this is because nsListBoxLayout::GetMinSize doesn't use the explicit minimum height when computing the minimum size to use.

Comment 11

[Neil Deakin]

Attachment: include test

Note sure why the listbox needs to set the minheight and I can't see anything broken without it.

Comment 12

[[e-mail]]

So basically the rows calculation is now all done in GetPrefSize?

Comment 13

[Neil Deakin]

(In reply to comment #12)
> So basically the rows calculation is now all done in GetPrefSize?

Seems like it

Comment 14

[fabi]

Is it predictable, when this fix is showing up in the nightly builds?

Comment 15

[Neil Deakin]

http://hg.mozilla.org/mozilla-central/rev/d0da383e6f08

Comment 16

[Tanner M. Young [:tmyoung]]

Verified with Mozilla/5.0 (Windows; U; Windows NT 6.0; WOW64; en-US; rv:1.9.3a5pre) Gecko/20100517 Minefield/3.7a5pre (.NET CLR 3.5.30729) ID:20100517035949

Comment 18

[Firefox Bug Husbandry Bot]

Moving to Core:XUL per https://bugzilla.mozilla.org/show_bug.cgi?id=1455336