141289 - :before/:after content doubled on some elements

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect, P1)

Description

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

We doubly-create :before/:after content for some elements.  In particular, CSS
describes :before/:after content as being created as the first-child or
last-child of the content to which the selectors match, not the previous sibling
or next sibling.  However, it gives *examples* with img:before that contradict
this, so we put a hack in ConstructHTMLFrame to support :before/:after on leaf
frames.  This hack causes a bunch of serious problems (bugs related to HR and
RemoveGeneratedContentFrameSiblings).  However, since we don't check
|processChildren| in ConstructHTMLFrame, we create the content the correct way
too in the case where the element isn't a leaf.

Testcase and patch to be attached.

Comment 1

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

Attachment: testcase

Comment 2

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

Attachment: patch

Comment 3

[Chris Waterson]

This fix makes no sense to me, but it works. Hold my hand and explain why? (It
would seem to me like it would preclude creating of the :before and :after
content on the <legend> element itself, for example.)

Comment 4

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

If |ProcessChildren| is true, then we call ProcessChildren, which creates the
generated content in the correct place, in the child list.

Comment 5

[Christopher Hoess (gone)]

Adding bugs with doubled GC so they get tested when this is fixed.

Comment 6

[Marc Attinasi]

Comment on attachment 81733 [details] [diff] [review]
patch

r=attinasi - thanks for the explanation David. Could you include a comment
saying why !processChildren is used? The comment you have is interesting, but
does not explain how ProcessChildren creates the generated content...

Comment 7

[Chris Waterson]

Comment on attachment 81733 [details] [diff] [review]
patch

sr=waterson

Comment 8

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

Fix checked in to trunk 2002-04-30 17:51 PDT.

Comment 9

[Christopher Hoess (gone)]

Fixed in new Linux CVS trunk build.

Comment 10

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

Reopening since I might want this on 1.0...

Comment 11

[Madhur Bhatia]

cc'ing myself

Comment 12

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

Ok, never mind about the branch, unless we want it in order to land the fix for
bug 141054.

Comment 13

[Hixie (not reading bugmail)]

VERIFIED FIXED using attachment.cgi 81730

Comment 14

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

*** Bug 168740 has been marked as a duplicate of this bug. ***