1625667 - [wpt-sync] Sync PR 22509 - make background-position-xy serialization work up to isomorphism

Status: RESOLVED FIXED

(Core :: Layout: Images, Video, and HTML Frames, task, P4)

Description

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

Sync web-platform-tests PR 22509 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/22509
Details from upstream follow.

George Steel <[e-mail]> wrote:

make background-position-xy serialization work up to isomorphism

Make the implementations of CSSValueFromComputedStyle for
background-position-x/y return correct values when three/four-value
syntax is used with background-position. Since these properties only
support single-value syntax, positions from the right or bottom will
use calc() values if they result in mixed lengths and percentages when
converted to be from the left/top. This is not the canonical form in
the css-backgrounds-4 spec proposal, but does not require changes to
the parser.

Add a reftest (passes without patch) for three/four-value
background-position syntax (there is currently only a manual test).
Add another version of the reftest (fails without patch) which takes
the above and attempts to write back the computed values of
background-position-x/y.

This is done in preparation to make transitions use normal keyframes
which require round-trip serialization of all transition properties.

Change-Id: I50e714746cc15fd0591bcd0a41cf9ecd56f55c44

Reviewed-on: https://chromium-review.googlesource.com/2121415
WPT-Export-Revision: e61178aee58f26f1cbc5d88ffa59c6b9ee495251

Comment 1

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

Pushed to try (stability) https://treeherder.mozilla.org/#/jobs?repo=try&revision=0cd4b7d3b3855de1722bec50b5f566d6d938c3fc

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3412745fb55a
[wpt PR 22509] - fix background-position-xy serialization for right/bottom offsets, a=testonly

Comment 3

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

Test result changes from PR not available.

Comment 4

[Andrei Ciure[:aciure]]

https://hg.mozilla.org/mozilla-central/rev/3412745fb55a