1576355 - css grid position incorrect after class name change

Status: RESOLVED FIXED

(Core :: Layout: Grid, defect)

Description

[James0x57]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Firefox/68.0

Steps to reproduce:

https://jsfiddle.net/s9wbd7ro/

Have a grid with grid areas that have a relative position and a % based "left" offset.
Remove the class name that causes the offset.
Re-add the class name that causes the offset.

Actual results:

the grid areas move relative to the parent Containing Block instead of relative to the grid column. The effect in the demo provided is that they move much further to the right after toggling the class name.

Expected results:

the grid areas should return to the original position, using the grid column as the Containing Block for the % calculation.

Comment 1

[Alice0775 White]

I try to bisect w/ layout.css.grid.enabled=true, However, it seems not a regression.
Before the following range: green rectangles are not displayed.
After the range: I can reproduce the the problem.

https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0ecd7d72f232304da046b352c457e039e35ceed7&tochange=2b73b0a4d52bbd72ef8d8720256b0bba59c7de01

FYI, The problem disappears after resize browser.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Thanks Alice, yeah then it's likely not to be a regression. Chances are that the RecomputePosition optimization is not accounting for the grid containing block properly...

Comment 3

[Mats Palmgren (inactive)]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=a38a7b8e8803b3a96160c2aafad7338e5ac15e78

Comment 4

[Mats Palmgren (inactive)]

Attachment: Bug 1576355 - Don't try to optimize position style changes for rel.pos. grid items. r=dholbert

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e7511b57c48e
Don't try to optimize position style changes for rel.pos. grid items.  r=dholbert

Comment 6

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/18684 for changes under testing/web-platform/tests

Comment 7

[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 8

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/e7511b57c48e

Comment 9

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

Upstream PR merged by moz-wptsync-bot