1581106 - [css-grid-2] 'repeat(auto-fill, <line-names>+)' isn't expanded correctly in a subgridded axis

Status: RESOLVED FIXED

(Core :: Layout: Grid, defect, P2)

Description

[Mats Palmgren (inactive)]

Attachment: Testcase

https://drafts.csswg.org/css-grid-2/#subgrid-per-axis
"The auto-fill keyword is only valid once per <line-name-list>, and repeats enough times for the name list to match the subgrid’s specified grid span (falling back to 0 if the span is already fulfilled)."

In the testcase, the first 3 grids should look the same.
The last grid should NOT look like the first 3 (it's the fallback to zero case - i.e. the 'y' line does not exist so the item should be placed in the last column).

Comment 1

[Mats Palmgren (inactive)]

It appears StyleGridTemplateComponent::RepeatAutoIndex() only reports the auto-repeat associated with the TrackList, not the Subgrid. (In the old C++ representation of this style value, the repeat index/flag was shared IIRC since they are mutually exclusive.) Anyway, there's some confusion about this in the Grid layout code currently.

Comment 2

[Mats Palmgren (inactive)]

Fwiw, this was actually working mostly correct before bug 1519958.
(I think the line-name matching was slightly wrong though. Our matching logic is assuming a track-repeat which merges the line-names from the line before/after with the edge names inside the repeat(), which shouldn't happen for a line-name-list repeat.)

Comment 3

[Mats Palmgren (inactive)]

Attachment: Bug 1581106 part 1 - Remove unused aNumRepeatTracks param (idempotent change). r=dholbert

Comment 4

[Mats Palmgren (inactive)]

Attachment: Bug 1581106 part 2 - Simplify LineNameMap ctor by deducing track clamping bounds instead of passing them as params (idempotent change). r=dholbert

Depends on D46372

Comment 5

[Mats Palmgren (inactive)]

Attachment: Bug 1581106 part 3 - [css-grid-2] Implement 'repeat(auto-fill, <line-names>)' in subgridded axis. r=emilio

Depends on D46373

Comment 6

[Daniel Holbert [:dholbert]]

Sorry for the delay here; I've been meaning to set aside some time to page the grid syntax & layout model back into my head so as to review this. Planning on getting through this tomorrow.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/75d66006c4a1
part 1 - Remove unused aNumRepeatTracks param (idempotent change).  r=dholbert
https://hg.mozilla.org/integration/autoland/rev/9fd948f30837
part 2 - Simplify LineNameMap ctor by deducing track clamping bounds instead of passing them as params (idempotent change).  r=dholbert
https://hg.mozilla.org/integration/autoland/rev/91d2317a3e64
part 3 - [css-grid-2] Implement 'repeat(auto-fill, <line-names>)' in subgridded axis.  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/19404 for changes under testing/web-platform/tests

Comment 9

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

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 10

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/75d66006c4a1
https://hg.mozilla.org/mozilla-central/rev/9fd948f30837
https://hg.mozilla.org/mozilla-central/rev/91d2317a3e64

Comment 11

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

Upstream PR merged by moz-wptsync-bot