1915977 - New wpt failures in /css/css-backgrounds/parsing/ [border-image-outset-computed.html, border-image-slice-computed.html]

Status: NEW

(Core :: Layout: Images, Video, and HTML Frames, defect)

Description

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

Syncing wpt PR 47895 found new untriaged test failures in CI

Tests Affected

New Tests That Don't Pass

• /css/css-backgrounds/parsing/border-image-outset-computed.html [wpt.fyi]
  • Property border-image-outset value 'calc(10 + (sign(2cqw - 10px) * 5))': FAIL (Chrome: PASS, Safari: FAIL)
  • Property border-image-outset value 'calc(10 + (sign(2cqw - 10px) * 5)) calc(20px + (sign(2cqw - 10px) * 5px)': FAIL (Chrome: PASS, Safari: FAIL)
• /css/css-backgrounds/parsing/border-image-slice-computed.html [wpt.fyi]
  • Property border-image-slice value 'calc(10 + (sign(2cqw - 10px) * 5))': FAIL (Chrome: PASS, Safari: FAIL)
  • Property border-image-slice value 'calc(10 + (sign(2cqw - 10px) * 5)) calc(20% + (sign(2cqw - 10px) * 5%))': FAIL (Chrome: PASS, Safari: FAIL)

CI Results

Gecko CI (Treeherder)
GitHub PR Head

Notes

These updates will be on mozilla-central once bug 1915913 lands.

Note: this bug is for tracking fixing the issues and is not
owned by the wpt sync bot.

This bug is linked to the relevant tests by an annotation in
https://github.com/web-platform-tests/wpt-metadata. These annotations
can be edited using the wpt interop dashboard
https://jgraham.github.io/wptdash/

If this bug is split into multiple bugs, please also update the
annotations, otherwise we are unable to track which wpt issues are
already triaged. Resolving as duplicate or closing this issue should
be cause the bot to automatically update or remove the annotation.

Comment 1

[Daniel Holbert [:dholbert] (PTO until 2/24)]

Looks like we're simply not supporting sign(...) where ... is subtraction between lengths of different units (which means we don't know if it's positive or negative).

The WebKit PR mentions calls this out like so:

These have the special property that their calc() cannot be evaluated
at parse time, as they require conversion data. As such, they need to
preserve and serialize the calc().

https://github.com/WebKit/WebKit/pull/32615

It sounds like they resolve the sign at used-value time.

Comment 2

[Daniel Holbert [:dholbert] (PTO until 2/24)]

See also emilio's bug 1915980 comment 1. (All 6 of the bugs that are blocked-by bug 1915913 -- this one as well as that one -- seem to be essentially the same issue with sign(FOO - BAR) being rejected in various properties, where FOO and BAR are using different context-dependent units, which means the sign() expression can't be trivially resolved)