28291 - [gfx scrollbar] Crash in GfxScrollFrame when style rules indicate display:none

Status: VERIFIED DUPLICATE of bug 21890

(Core :: XUL, defect, P3)

Description

[jst]

Loading an XML document with a stylesheet containing

* {
  display: block;
  padding: 20px;
}

makes the elements in the GFX scrollbars in mozilla get a padding of 20px!

I'll attach testcases...

Comment 1

[jst]

Attachment: Stylesheet for the sample XML file.

Comment 2

[jst]

Attachment: XML testcase.

Comment 3

[jst]

Attachment: Screenshot

Comment 4

[jst]

I also noticed that specifying

* {
  display: none;
}

makes mozilla crash in the GFX scrollbar code since it assumes that some frames
exist even if they don't.

Comment 5

[Marc Attinasi]

This is the correct behavior: if you specify a style in a user stylesheet then 
that overrides the styles specified by the user agent. The global style rule is 
a very powerful one...

There is a valid bug here, and that is the crash in GfxScrollFrame when the 
following style rule is set in an HTML or XML page:

* {
   display : none;
}

The GfxScrollFrame method SetInitialChildList should check the scrollbar frames 
for NULL before dereferencing them. I'm changing this bug into a crash bug in 
GfxScrollFrame and sending to eric vaughan.

Comment 6

[Marc Attinasi]

Attachment: HTML test case showing crash in GfxScrollFrame

Comment 7

[Johnny Stenback (:jst)]

The crash in GfxScrollFrame is definitely not the *only* bug here, regardless of
the style in the *document* that is loaded the GFX scrollbars should look the
same! The scrollbars are not part of the HTML document (well in a way they are
but...)! The only stylesheets that should affect the scrollbars is the chrome
stylesheets, *not* the *document* stylesheets!

Comment 8

[Eric Vaughan]

hyatt,

passing to you because scrollbars should not be styled by the * selector.

Comment 9

[David Hyatt]

*** This bug has been marked as a duplicate of 21890 ***

Comment 10

[Johnny Stenback (:jst)]

Marking verified dup.