1811526 - [wpt-sync] Sync PR 38085 - FontFallbackList::CompositeKey should take current_family->FamilyIsGeneric() into account

Status: RESOLVED FIXED

(Core :: Layout: Text and Fonts, task, P4)

Description

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

Sync web-platform-tests PR 38085 into mozilla-central (this bug is closed when the sync is complete).

PR: https://github.com/web-platform-tests/wpt/pull/38085
Details from upstream follow.

Frédéric Wang <[e-mail]> wrote:

FontFallbackList::CompositeKey should take current_family->FamilyIsGeneric() into account

FontFallBackList::GetShapeCache calculates the key of a FontDescription
via FontFallbackList::CompositeKey as follows:

1. Initialize the key's data/hash in FallbackListCompositeKey's
   contructor. This ignores FontDescription::family_list_ but takes
   into account FontDescription::generic_family_ via BitmapFields() and
   AuxiliaryBitmapFields().

2. Update key's data/hash via FallbackListCompositeKey::Add and
   FontDescripion::CacheKey for each item of
   FontDescription::family_list_

As a consequence, this calculation is not sufficient to distinguish
FontDescription created from things like font-family: "system-ui"
(quoted) and font-family: system-ui (unquoted) [1] [2]. The
ShapeCache is still used in canvas and so it is possible to tweak
WPT test css/css-fonts/generic-family-keywords-001.html in order to
exhibit that issue.

This CL modifies FontFallbackList::CompositeKey to ensure that
FamilyIsGeneric() is taken into account for each item of
FontDescription::family_list_. It also adds the canvas version of
the corresponding WPT test mentioned above.

[1] The latter specifies a generic font family but the former does not.
See https://drafts.csswg.org/css-fonts-4/#family-name-syntax
[2] For generic family listed in FontDescription::GenericFamilyType,
it is necessary to add another generic family to the font-family
so that they use the same FontDescription::generic_family_.
For details, see https://docs.google.com/document/d/1nYJzL-MWQrTmf9Z-KscTWuM_5n6-IVdJeEllJ3Appro/edit

Bug: 1408485
Change-Id: Iac95ccf0fd345352cce963f77a60818060a40dc7
Reviewed-on: https://chromium-review.googlesource.com/4176920
WPT-Export-Revision: 53ec8bcbcf5927d00ded6ee5986341f528ac5df2

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=355ef028e028698de1aafae2dd57225e220f699b

Comment 2

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

Test result changes from PR not available.

Comment 3

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

Test result changes from PR not available.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fdff471795f6
[wpt PR 38085] - FontFallbackList::CompositeKey should take current_family->FamilyIsGeneric() into account, a=testonly
https://hg.mozilla.org/integration/autoland/rev/2f7f65cb8508
[wpt PR 38085] - Update wpt metadata, a=testonly

Comment 5

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

Test result changes from PR not available.

Comment 6

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/fdff471795f6
https://hg.mozilla.org/mozilla-central/rev/2f7f65cb8508