1852323 - Firefox will fail css/css-masking/clip-path/clip-path-polygon-010.html after that test gets updated to match the spec

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

As of this moment, we're alone in passing this WPT test:
https://wpt.fyi/results/css/css-masking/clip-path/clip-path-polygon-010.html

However, per https://github.com/web-platform-tests/interop/issues/409 , that test doesn't actually match the spec; and progers is likely updating the test to make it match. Hence, I'm preemptively filing this bug.

(Before a spec change 5 years ago, the spec said that the used value of clip-path's fill-box keyword was border-box, for elements with a CSS layout box (i.e. non-SVG conent).
That's what the test currently expects and what we seem to implement. However, as of that spec change, the used value is now supposed to be content-box.)

It looks like this is at least one of the spots that we need to update:
https://searchfox.org/mozilla-central/rev/c1fb133ca4901985070e519c92322b432fa254c5/layout/base/nsLayoutUtils.cpp#9641-9642,9655

Possibly other nearby usages of that StyleGeometryBox::FillBox enum as well.

Comment 1

[Daniel Holbert [:dholbert]]

Similar change is coming for another test:
https://github.com/web-platform-tests/interop/issues/410
wpt.fyi: https://wpt.fyi/results/css/css-masking/clip-path/clip-path-fillBox-1a.html

Same situation as in comment 0; and the same internal fix on our end should be sufficient to get us back to passing, once the test has been changed.

Comment 2

[Daniel Holbert [:dholbert]]

boris, could you take this masking fix when you've got cycles?

Comment 3

[Daniel Holbert [:dholbert]]

(The tests were updated and wpt.fyi is showing us as failing these tests now.)

Comment 4

[Boris Chiou [:boris]]

Sure. I will take a look at this. This should be easy to fix.

Comment 5

[Boris Chiou [:boris]]

Attachment: Bug 1852323 - Part 1: Update the mapping of geometry box for clip-path.

It seems mask-origin/mask-clip/clip-path use different mapping for
geometry-box. We should specialize each one.

Comment 6

[Boris Chiou [:boris]]

Attachment: Bug 1852323 - Part 2: Fix the mapping of StyleGeometryBox for mask-clip.

Also, make sure mask-origin/mask-clip follow the spec.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/46bb8c25b946
Part 1: Update the mapping of geometry box for clip-path. r=emilio
https://hg.mozilla.org/integration/autoland/rev/865e00dab584
Part 2: Fix the mapping of StyleGeometryBox for mask-clip. r=emilio

Comment 8

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/42468 for changes under testing/web-platform/tests

Comment 9

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/46bb8c25b946
https://hg.mozilla.org/mozilla-central/rev/865e00dab584

Comment 10

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

Upstream PR merged by moz-wptsync-bot