1938927 - Cyclic dependency on a custom property with an em unit breaks unrelated custom properties using ems

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Roman Komarov]

Attachment: Firefox cyclic bug.html

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:135.0) Gecko/20100101 Firefox/135.0

Steps to reproduce:

1. Open https://codepen.io/kizu/pen/raBwegm (or the attached .html copy)
2. Look at the font-size

OR

1. Add a font-size that uses a custom property which uses em unit.
2. Specify another unrelated custom property that contains a cyclic dependency (involving itself or other custom properties), AND a mention of the em unit somewhere.

Actual results:

The text is not affected by the change in font-size: the text on the page stays in the default font-size.

Expected results:

The font-size that uses a custom property and em unit should work: the text in the CodePen should get its font-size increased from all three elements involved: html, body and .test.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Layout: Text and Fonts' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Mayank Bansal]

Thanks for reporting and sharing a reduced testcase!

Bisection:
Bug 1855110: Part 3 - Properly resolve registered custom properties using font-relative units. r=firefox-style-system-reviewers,emilio
Differential Revision: https://phabricator.services.mozilla.com/D196195

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1855110

Comment 4

[Emilio Cobos Álvarez (:emilio)]

(ni?ing David too in case he gets to take a look sooner than me)

Comment 5

[David Shin[:dshin]]

Attachment: Bug 1938927: Cyclic dependencies consisting only of non-computed custom properties should not mark any non-custom property as invalid-at-computed time. r=#style

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/84fa2a16d2fc
Cyclic dependencies consisting only of non-computed custom properties should not mark any non-custom property as invalid-at-computed time. r=firefox-style-system-reviewers,emilio

Comment 7

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/49919 for changes under testing/web-platform/tests

Comment 8

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

Upstream PR merged by moz-wptsync-bot

Comment 9

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/84fa2a16d2fc

Comment 10

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:dshin, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox135 to wontfix.

For more information, please visit BugBot documentation.

Comment 11

[David Shin[:dshin]]

Comment on attachment 9444997 [details]
Bug 1938927: Cyclic dependencies consisting only of non-computed custom properties should not mark any non-custom property as invalid-at-computed time. r=#style

Beta/Release Uplift Approval Request

• User impact if declined/Reason for urgency: Valid registered custom property considered invalid & not applying
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Small change + WPT test (non-computed-unit-cycles.html) + 2 weeks passed to filter out any perf issue
• String changes made/needed: None
• Is Android affected?: Yes

Comment 12

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9444997 [details]
Bug 1938927: Cyclic dependencies consisting only of non-computed custom properties should not mark any non-custom property as invalid-at-computed time. r=#style

Approved for 135.0b3 and 128.7esr.

Comment 13

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-beta/rev/8909824a9101

Comment 14

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-esr128/rev/581dd61bf1b4