Use latest nightly. Make sure Fission is enabled.
Go to https://codepen.io/amit_sheen/pen/NWgJLKd
Configure the page such that the demo is on the left pane, and the editor is on the right pane
Pinch-zoom slowly

AR: Glitches at the edge of the screen
ER: Not so

Regression gave me the following :

Bug 1732358 - Part 5: Add the fission rollout slug to the GRADUATION_SET, r=mythmon
Depends on D133008
Differential Revision: https://phabricator.services.mozilla.com/D133659

With Fission disabled, a build from Jul-21 doesnt repro the bug. But when I manually enabled fission, I could repro.
Therefore, this bug is triggered by fission (but may have root cause elsewhere)

If you export the demo to your local machine and run the demo from there, the bug doesnt repro.
Tentatively marking bug 1732358 as the regressor.

Set release status flags based on info from the regressing bug 1732358

:nika, since you are the author of the regressor, bug 1732358, could you take a look?
For more information, please visit auto_nag documentation.

Redirecting ni? to :emilio who is more familiar with the setup we use for pinch-zoom with Fission.

This is probably an APZ and/or WebRender bug, more than fission per se. Probably WR is clipping / culling primitives a bit too aggressively or so?

With my daily profile, the demo causes Nightly to turn white, but no crash report is generated. The following message is printed in log :

2022-07-30T09:42:19.423000: INFO : platform_repository: https://hg.mozilla.org/mozilla-central
2022-07-30T09:42:19.423000: INFO : platform_version: 105.0a1
2022-07-30T09:42:35.061000: INFO : b'[GFX1-]: DCompositionSurface::BeginDraw failed: 0x80070057 Rect(x=526336, y=525312, w=0, h=0)'
2022-07-30T09:42:35.062000: INFO : b'[GFX1-]: Handling webrender error 4'
2022-07-30T09:42:35.062000: INFO : b'[GFX1-]: Fallback WR to SW-WR + D3D11'

(this might be the same as bug 1750348)

Un-assigning for now since it's not a recent regression, but we'll need to fix this one in WR - from comment 8 it appears to be an issue with how we use DC.