1889690 - Pinch-zooming on pretty much any page leads to stuff "sliding" on the screen

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect, P3)

Description

[Mayank Bansal]

Go to https://bugzilla.mozilla.org/enter_bug.cgi
Pinch-zoom

AR: Stuff on the screen starts sliding on the screen
ER: Not so

Bisection:
Bug 1888400 - Add a test. r=gw

Differential Revision: https://phabricator.services.mozilla.com/D206099

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Mayank Bansal]

Other simple pages: https://www.google.com/search?client=firefox-b-d&q=barak+obama

Comment 3

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

Set release status flags based on info from the regressing bug 1888400

Comment 4

[Brad Werth [:bradwerth]]

Not replicating for me on my Windows laptop, nor in macOS. I note that my Windows system has "Windows Device Pixel Ratios" of 1, rather than the 1.5 in your about:support. Try a different DPI, does that make a difference? Nical can elevate the severity if he can replicate.

Comment 5

[Brad Werth [:bradwerth]]

Still doesn't replicate for me in Windows with a 1.5 pixel ratio. Can't replicate.

Comment 6

[Mayank Bansal]

Attachment: bandicam 2024-04-05 07-31-22-908.mp4

Comment 7

[Mayank Bansal]

can repro with DPi=1
You can also try on this page: https://codepen.io/trending
The background box shadow thing will start to slide

Comment 8

[Brad Werth [:bradwerth]]

(In reply to Mayank Bansal from comment #7)

can repro with DPi=1
You can also try on this page: https://codepen.io/trending
The background box shadow thing will start to slide

Great, thank you, I am replicating on macOS on that page. Let's see what Nical can discover about the root cause.

Comment 10

[Mayank Bansal]

I can still repro with the latest Nightly https://hg.mozilla.org/mozilla-central/rev/ea8ea972270ddb95f071f900f9199fb7ff95bb10

Comment 11

[Donal Meehan [:dmeehan]]

Resolving as fixed by backing out the regressor
https://bugzilla.mozilla.org/show_bug.cgi?id=1888400#c9

Comment 12

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

I was able to replicate the issue on an affected Firefox Nightly build from 2024-04-04, using macOS 12.6.6, while following the steps described in Comment 0, Comment 2 and Comment 7.
Verified as fixed on Firefox Beta 126.0b8, build ID 20240501022718, using macOS 12.6.6 and Windows 11.
The elements from the mentioned webpages are no longer sliding on the screen when pinch-zooming.
On Ubuntu I am unable to pinch-zoom.