384876 - Padding gets added at both sides when overflow is used

Status: RESOLVED FIXED

(Core :: Layout: Block and Inline, defect, P3)

Description

[Daniel Kirsch]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.4) Gecko/20070515 Firefox/2.0.0.4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; de-DE; rv:1.9a6pre) Gecko/20070617

When defining a padding for one side and set overflow to "auto" or "hidden", the padding is added at both sides. (This worked with Firefox 2.0.0.4)

Reproducible: Always

Comment 1

[Daniel Kirsch]

Attachment: HTML testcase

Comment 2

[Eli Friedman]

Confirming, and noting the following comment:
http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/layout/generic/nsGfxScrollFrame.cpp&rev=3.307&mark=678#678

I can't find a bug to dup this to, although that doesn't mean there isn't one on file...

Comment 3

[Eli Friedman]

Attachment: Patch

GetPrefWidth should be correct here because a scrollframe isn't a normal container.

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 272690 [details] [diff] [review]
Patch

>+    // XXX This isn't really right; we shouldn't be adding in space
>+    // for a vertical scrollbar when we might not need it

Yes we should.

Comment 5

[Eli Friedman]

Fine; consider the comment gone.  (It does lead to slightly odd-looking results with this testcase, but I suppose that's expected.)

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 272690 [details] [diff] [review]
Patch

minus the comment

Comment 7

[Eli Friedman]

Checked in with reftest.

Comment 8

[Daniel Kirsch]

I still see a difference in the latest trunk compared to Mozilla/5.0 (Windows; U; Windows NT 5.1; de; rv:1.8.1.7) Gecko/20070914 Firefox/2.0.0.7
The third line in the testcase using overflow:auto has a bottom border that's about 16px larger than expected.

Comment 9

[Daniel Kirsch]

Attachment: Screenshot from 1.9a9pre

The screenshot shows the extra padding at the third line.
Used build: XULRunner, Mozilla/5.0 (Windows; U; Windows NT 5.1; de-DE; rv:1.9a9pre) Gecko/2007100911

Comment 10

[Robert O'Callahan (:roc) (email my personal email if necessary)]

I think comment #8 is simply caused by comment #4... we're adding the width of a scrollbar to the overflow:auto case. David says we should, I don't disagree. Closing this FIXED since it really was.

Comment 11

[Daniel Kirsch]

I don't agree. Why is the padding added even when no scrollbar is needed?
In 1.8 no padding was added, IE doesn't add one, Opera doesn't add one too. Only Mozilla 1.9 releases shows this unexpected behaviour.

Comment 12

[philippe (part-time)]

Attachment: screenshot of testcase

From top to Bottom: Gecko 1.9, Opera 9.5b, WebKit build
As seen on OS X 10.4.11

Comment 13

[Robert O'Callahan (:roc) (email my personal email if necessary)]

OK, file a new bug, because it's definitely not this bug. David should make the call on this one.

Comment 14

[Daniel Kirsch]

Hmmm... well.
bug 405952 filed.