1862249 - Trailing ideographic space (U+3000) should hang at end-of-line

Status: REOPENED

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

Description

[Jonathan Kew [:jfkthame]]

Testcase: http://wpt.live/css/css-text/white-space/trailing-ideographic-space-001.html

This fails because we do not treat the ideographic space as hanging at the end of the first line; therefore it contributes its width to its parent <div>, and the red background becomes visible.

A couple of other WPT tests currently fail similarly.

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1862249 - patch 1 - Make a couple of trailing-ideographic-space tests more robust. r=#layout

In addition to the width behavior that these tests are actually about,
we get a spurious rendering discrepancy at least on Linux (depending on
font metrics) because the height of the green background applied to the
<div> does not necessarily match that of a background applied to a <span>
within it.

To avoid this, we can apply the green background to an inline (span)
element, not to the containing block (div), so that it always gets a
consistent height.

Comment 2

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1862249 - patch 2 - Recognize ideographic space (U+3000) as trimmable, so it can hang at end-of-line. r=#layout

Fixing this also resolves a couple of text-transform test failures, because what was
failing was not the text-transform itself, but rather the trailing-ideographic-space
treatment.

Depends on D192394

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/81edb6c9b2f3
patch 1 - Make a couple of trailing-ideographic-space tests more robust. r=layout-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/3ff9d913d60a
patch 2 - Recognize ideographic space (U+3000) as trimmable, so it can hang at end-of-line. r=layout-reviewers,emilio

Comment 4

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/42928 for changes under testing/web-platform/tests

Comment 5

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/81edb6c9b2f3
https://hg.mozilla.org/mozilla-central/rev/3ff9d913d60a

Comment 6

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

Upstream PR merged by moz-wptsync-bot

Comment 7

[Jonathan Kew [:jfkthame]]

Re-opening, as the fix that landed here has just been backed out in https://hg.mozilla.org/mozilla-central/rev/877aa1219c43 to fix bug 1870973 and other reported regressions. The backout has also been uplifted to Fx122.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

Backed out for 121.0.1 also