1122366 - Margin collapsing and vertical writing-mode

Status: RESOLVED FIXED

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

Description

[Gérard Talbot]

4 tests involving collapse-through elements
-------------------------------------------

http://www.gtalbot.org/BrowserBugsSection/CSS3WritingModes/s74-margin-collapse-024.xht

http://www.gtalbot.org/BrowserBugsSection/CSS3WritingModes/s74-margin-collapse-025.xht

http://www.gtalbot.org/BrowserBugsSection/CSS3WritingModes/s74-margin-collapse-030.xht

http://www.gtalbot.org/BrowserBugsSection/CSS3WritingModes/s74-margin-collapse-031.xht

Expected result
---------------

http://www.gtalbot.org/BrowserBugsSection/CSS3WritingModes/ref-filled-green-100px-square.xht

Notes
-----

- Chrome 39.0.2171.99 and IE11 pass those 4 tests
- I am using Firefox 37.0a1 buildID=20150109145718
- I use Linux 3.16.0-29-generic x86_64, Qt: 4.8.6, KDE 4.14.1; Kubuntu (utopic) 14.10
- I've searched for duplicates and did not find any.

Gérard

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Make nsBlockFrame::IsSelfEmpty aware of vertical writing modes

This happens because nsBlockFrame::IsSelfEmpty is not vertical-aware, and so it doesn't realize the zero-width <div>s here are empty and margins can collapse through them. With the attached patch, the testcases all work as expected.

Comment 2

[Jonathan Kew [:jfkthame]]

Inspection of the code suggests that nsInlineFrame::IsSelfEmpty also needs similar vertical-mode love. I'll add a patch for that after some additional testing.

Comment 3

[Jonathan Kew [:jfkthame]]

Attachment: pt 2 - Also make nsInlineFrame::IsSelfEmpty aware of vertical writing modes

The comparable fix for nsInlineFrame.

Comment 4

[Jonathan Kew [:jfkthame]]

Attachment: Reftest for margin-collapsing through empty element in vertical mode

And here's a simple reftest based on the testcase here.

Comment 5

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

Comment on attachment 8550293 [details] [diff] [review]
pt 2 - Also make nsInlineFrame::IsSelfEmpty aware of vertical writing modes

r=dbaron, although it seems like there should be a simpler way to write things like this

Comment 6

[Jonathan Kew [:jfkthame]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/8c5e7ffa005d
https://hg.mozilla.org/integration/mozilla-inbound/rev/ba8558804ee7
https://hg.mozilla.org/integration/mozilla-inbound/rev/b86864fd9d60

Comment 7

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/8c5e7ffa005d
https://hg.mozilla.org/mozilla-central/rev/ba8558804ee7
https://hg.mozilla.org/mozilla-central/rev/b86864fd9d60