1493264 - Thin softly flickering line on superhuman.com

Status: NEW

(Core :: Graphics: WebRender, defect, P4)

Description

[Darkspirit]

Attachment: 2018-09-21_21-25-40.mp4

https://hg.mozilla.org/integration/autoland/graph/76d218ea875e

> 76d218ea875e: Bug 1489337 - Don't set preserve-3d to true when creating WebRender commands for nsDisplayPerspective since it's not needed. r=jrmuizel 
mozregression --repo autoland --launch 76d218ea875e --pref gfx.webrender.all:true -a https://superhuman.com/
first bad (right window)

> 96059b4f6d8a: bug 1490119: Add build system bits for building dep updater. r=firefox-build-system-reviewers,mshal,rstrong 
mozregression --repo autoland --launch 96059b4f6d8a --pref gfx.webrender.all:true -a https://superhuman.com/
last good (left window)

Last good has been backed out from central, so it was a bit trouble to find it.
Is this now just the usual snapping problem (bug 1487858) but oblique (never seen before), or unique and something different?

Comment 1

[Darkspirit]

Attachment: Screenshot_20180921_214516.png

Comment 2

[Darkspirit]

I think with bug 1451439 those tiny lines wouldn't flicker anymore, but they would be still there.

Comment 3

[Darkspirit]

Attachment: Screenshot_20180926_213711.png

Another dashed line, at 50% zoom. Same range. Could this be similar to the old bug 1401665?

Comment 4

[Jared Wein [:jaws] (please needinfo? me)]

Markus, is this actionable given the STR and regression range? Is this a duplicate of bug 1447093?

Comment 5

[Markus Stange [:mstange]]

If we can reproduce it, or even find out what GPU + driver it happens on, then it's actionable. The issue from comment 3 looks very similar to bug bug 1401665 or possibly bug 1447093; but the issue in comment 0 looks like z-fighting rather than out-of-bounds sampling.