467460 - Inconsistent positioning with -moz-transform:translate, position:fixed

Status: VERIFIED FIXED

(Core :: Layout: Positioned, defect, P2)

Description

[Jesse Ruderman]

The two files have the same final DOM, so they should look identical.

Based on layout/reftests/transform/abspos-1b.html

Comment 1

[Jesse Ruderman]

Attachment: testcase (dynamic)

Comment 2

[Jesse Ruderman]

Attachment: reference (static)

Comment 3

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

The problem is that in the dynamic one we make it a normal fixed-positioned child of the viewport rather than putting it on the absolute list of the element with transform, as we should do.

Comment 4

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

Attachment: patch

This is pretty trivial; just set things up in the dynamic case the same way we do when constructing from the top.

I probably ought to add a test for both constructors somehow, but so far I only have Jesse's.  Luckily I fixed the wrong constructor first, so I noticed there were two.

Comment 5

[cmtalbert]

(In reply to comment #4)
> I probably ought to add a test for both constructors somehow, but so far I only
> have Jesse's.  Luckily I fixed the wrong constructor first, so I noticed there
> were two.
I intended to help you out with this, but it looks to me as if we only call the four parameter constructor.  I did some searching through MXR, and really this is the only instance of us constructing this object that I've found:

http://mxr.mozilla.org/mozilla-central/source/layout/base/nsCSSFrameConstructor.cpp#7933

Is there something I'm missing?

Also marking this as wanted 1.9.1 since we are touting our CSS-Tranform support in that release, this should get checked in to that branch too after it bakes.

Comment 6

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

Mostly we construct them on the stack, so you'll see "nsFrameConstructorState state(...)".

Comment 7

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

Fixed on mozilla-central: http://hg.mozilla.org/mozilla-central/rev/1fb56a23792d

Comment 8

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

Comment on attachment 350917 [details] [diff] [review]
patch

Somewhat nasty and pretty trivial-to-fix incremental layout bug related to a new feature (-moz-transform).

Comment 9

[Thomas Goldstein]

Shouldn't this be backported to 1.9.1, as this feature will be introduced in 3.1, and so the bug hasn't been shipped in a stable release yet?

Comment 10

[Jesse Ruderman]

dbaron already requested approval for the backport :)

Comment 11

[Mike Beltzner [:beltzner, not reading bugmail]]

Comment on attachment 350917 [details] [diff] [review]
patch

a191=beltzner

Comment 12

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

David, don't forget to land this!

Comment 13

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

Fixed on 1.9.1: http://hg.mozilla.org/releases/mozilla-1.9.1/rev/cd51ade5d696

Comment 14

[Aakash Desai [:aakashd]]

verified FIXED on builds:

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090721
Minefield/3.6a1pre ID:20090721044139

and

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.1pre) Gecko/20090720
Shiretoko/3.5.1pre ID:20090720042942