1529241 - Ligated emoji sequences like 👨‍💻 may get wrapped to a new line

Status: RESOLVED FIXED

(Core :: Layout: Text and Fonts, defect, P3)

Description

[Mert Yazicioglu]

Attachment: firefox-65-emoji-wrap.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:65.0) Gecko/20100101 Firefox/65.0

Steps to reproduce:

Put an emoji[0] inside an element that does not have enough width[1].

[0] Must be an emoji sequence (an emoji with more than one code point) like 👨‍💻.
[1] What's enough varies by the font-size of the wrapping element.

Actual results:

First part of the emoji remains on the actual line, and the rest of the emoji gets wrapped to a new line/multiple new lines. An example is attached.

Expected results:

Emojis are not supposed to wrap.

Comment 1

[Gingerbread Man]

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:67.0) Gecko/20100101 Firefox/67.0
20190220040540

:jfkthame NI to put this on your radar, since it's another issue with ligated emoji.

Comment 2

[Jonathan Kew [:jfkthame]]

Yeah, this is one of a number of issues where we don't currently recognize the full cluster rules that should be used with emoji sequences.

Comment 3

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1529241 - Preliminary cleanup - remove gfxPlatform::SetupClusterBoundaries, as it doesn't have any callers. r=m_kato

Comment 4

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1529241 - Handle emoji-zwj sequences in unicode::ClusterIterator so that we avoid breaking them across lines or during selection. r=m_kato

Depends on D25100

Comment 5

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1529241 - Add WPT test for line-breaking of various emoji clusters. r=m_kato

(The tests currently fail on macOS using mozilla CI because of the old version of macOS present there,
which has an emoji font that doesn't support some of these sequences. On macOS 10.13, the tests pass
as expected, so the failure annotations are temporary until the test environment is updated in bug
https://bugzilla.mozilla.org/show_bug.cgi?id=1530474.)

Depends on D25101

Comment 6

[Jonathan Kew [:jfkthame]]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=128c6daf3eff4ec4af0d4ad6c9a78c174957de50

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/10850a60571a
Preliminary cleanup - remove gfxPlatform::SetupClusterBoundaries, as it doesn't have any callers. r=m_kato
https://hg.mozilla.org/integration/autoland/rev/a20ab6d47774
Handle emoji-zwj sequences in unicode::ClusterIterator so that we avoid breaking them across lines or during selection. r=m_kato
https://hg.mozilla.org/integration/autoland/rev/f40a5097cc74
Add WPT test for line-breaking of various emoji clusters. r=m_kato

Comment 8

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/10850a60571a
https://hg.mozilla.org/mozilla-central/rev/a20ab6d47774
https://hg.mozilla.org/mozilla-central/rev/f40a5097cc74

Comment 11

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/16238 for changes under testing/web-platform/tests