1799216 - css transforms display bug

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Klaus Reinfeld]

Attachment: firefox106bug.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:106.0) Gecko/20100101 Firefox/106.0

Steps to reproduce:

Here an example (many other sites are affected too) - see in this example the bottom 'bar' and compare it with any other browser:

https://krpano.com/tours/paris/

Actual results:

That gray/blue bar is rendered wrong, one part looks vertically stretched and so overlaps other elements and results in a wrong output.

The related html elements are css transformed.

The problem happens since Firefox 106.

Tested on Windows and Mac and with different device-pixels, the problem is everywhere the same.

Expected results:

Just compare with any other browser or see the attached screenshot.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::CSS Parsing and Computation' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[Mayank Bansal]

2022-11-05T06:25:26.589000: DEBUG : Found commit message:
Bug 1661147 - When starting a new list, copy inputs from the stack as well. r=gfx-reviewers,bradwerth

Copying outputs with a null clip input is not sound if one of the other
items expand outside of our bounds, such as in the case of a blur
filter.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1661147

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Attachment: Somewhat reduced test-case.

Somehow pointer-events affects the rendering here which is clearly bogus. Will look, thanks.

Comment 5

[Emilio Cobos Álvarez (:emilio)]

Attachment: More reduced.

Comment 6

[Emilio Cobos Álvarez (:emilio)]

Attachment: Even more reduced.

Okay I see what's going on I think. pointer-events: none causes us to not create a display item for the middle item at all, which causes us to ignore its clip, I believe.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Attachment: Simpler frame tree.

(Sorry for the spam)

Comment 9

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1799216 - Keep clip chain id in sync when switching items that affect clip positioning. r=#gfx-reviewers

Bug 1661147 made us correctly inherit the clip chain. We do fix up the
scroll id etc before pushing a new ASR override etc, but we didn't fix
up the clip chain ID.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/2d53a4acaad2
Keep clip chain id in sync when switching items that affect clip positioning. r=gfx-reviewers,gw

Comment 11

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/36837 for changes under testing/web-platform/tests

Comment 12

[Klaus Reinfeld]

Great work! The quick problem analyzing, localizing and fixing was impressive. Thanks!

Comment 13

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/2d53a4acaad2

Comment 14

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:emilio, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox107 to wontfix.

For more information, please visit auto_nag documentation.

Comment 15

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 9302173 [details]
Bug 1799216 - Keep clip chain id in sync when switching items that affect clip positioning. r=#gfx-reviewers

Beta/Release Uplift Approval Request

• User impact if declined: comment 0
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: comment 0
• List of other uplifts needed: none
• Risk to taking this patch: Medium
• Why is the change risky/not risky? (and alternatives if risky): While not the lowest-risk-patch ever, it's well-scoped and this code-path is relatively well tested, so it might be worth uplifting.
• String changes made/needed: none
• Is Android affected?: Yes

Comment 16

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

Upstream PR merged by moz-wptsync-bot

Comment 17

[Giorgia Nichita, Release Desktop QA]

Reproduced this issue on an affected Nightly build from 2022-11-04, on Win 10 and Ubuntu 21.04.
Verified as fixed on 108.0a1 (20221107212933) on Win 10, Ubuntu 21.04 and macOS 10.13.

Leaving the qe-verify+ flag until this gets verified in beta as well.

Comment 18

[Pascal Chevrel:pascalc]

We are in 107 RC week, wontfix 106.

Comment 19

[Donal Meehan [:dmeehan]]

Comment on attachment 9302173 [details]
Bug 1799216 - Keep clip chain id in sync when switching items that affect clip positioning. r=#gfx-reviewers

Switching beta uplift request to release, 107 is now in RC.
Keeping on the radar for potential uplift later for a ride-along.

Comment 20

[Timothy Nikkel (:tnikkel)]

Might want to slow down on the uplift, this is suspected of causing a perf regression, bug 1799800.

Comment 21

[Emilio Cobos Álvarez (:emilio)]

Comment on attachment 9302173 [details]
Bug 1799216 - Keep clip chain id in sync when switching items that affect clip positioning. r=#gfx-reviewers

Alright let's hold off.

Comment 22

[Giorgia Nichita, Release Desktop QA]

Closing this as Verified fixed and removing the qe+ flag.