1683753 - macOS: Some article title text is intermittently rendered with parts shifted to the wrong position

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect, P2)

Description

[Chris Peterson [:cpeterson]]

Attachment: screenshot.png

See the attached screenshot of https://godotengine.org/article/new-showcase-for-projects-made-with-godot

I first noticed this bug on 2020-12-20 and I've seen it about three times since then. The problem only seems to affected large text, like the H1 text of the article title ("Announcing the new showcase for projects made with Godot") on https://godotengine.org/article/new-showcase-for-projects-made-with-godot .

I suspect this is a SW-WR bug. I had to take this screenshot using the macOS screenshot tool because Firefox's screenshot tool rendered the text correctly.

I have my default page zoom at 110%, which might be related. When I see the bug, if I reduce the page zoom to 100%, then text is rendered correctly, IIRC. But I also think I've seen the bug when reloading an affected page at page zoom 100%.

Comment 1

[Darkspirit]

So far I haven't been able to repro this on Debian Testing.

Comment 2

[Chris Peterson [:cpeterson]]

(In reply to Darkspirit from comment #1)

So far I haven't been able to repro this on Debian Testing.

I saw this bug on macOS with gfx.webrender.software = true. I'll try testing Windows.

Comment 3

[Chris Peterson [:cpeterson]]

I just tried testing Windows. My about:support says WebRender (Software D3D11). I wasn't able to reproduce the bug. However, the bug is intermittent, so perhaps Windows is affected and I was just not "lucky" enough to reproduce it.

Comment 5

[Jeff Muizelaar [:jrmuizel]]

I wonder if Nical's texture cache work is causing this.

Comment 6

[Chris Peterson [:cpeterson]]

I also saw this bug on the H1 title text of this article ("From Balenciaga to Basics: Lessons from Our Pivot to API Tooling") in two different tabs:

https://www.akitasoftware.com/blog/2020/12/22/from-balenciaga-to-basics-lessons-from-our-pivot-to-api-tooling

Comment 7

[Chris Peterson [:cpeterson]]

Attachment: body-screenshot.png

Correction:

• I reproduced this bug without SW-WR (gfx.webrender.all = true and gfx.webrender.software = false).
• I reproduced this bug the body text of an article (specifically Pocket's Article View). See the attached body-screenshot.png.

Comment 8

[Darkspirit]

(In reply to Chris Peterson [:cpeterson] from comment #0)

I first noticed this bug on 2020-12-20

bug 1679751 comment 16 landed in 20201217092748.
(Regression range is not proven, just assumed.)

Comment 9

[Sören Hentzschel]

I also see this sometimes on a late 2018 MacBook Pro with macOS 11.1 and WebRender (I don't use software WebRender) since a few days. So far I saw this on GitHub and in Cleverreach but it doesn't happen very often so it's really hard to reproduce.

Comment 10

[Dennis Schubert [:denschub]]

I can reproduce this as well, with Hardware WebRender. It's ahrd to reproduce, but it happens fairly reliable after an hour or two of using the web for me. And once it starts, almost every page I open has some broken text on it, and it stays that way until I grudgingly reboot the browser.

:aosmond, you marked this as P3, but given this appears to be a recent regression that potentially affects a lot of users if their session is old enough, I feel like this might not be right. Could you reconsider that? :)

Comment 11

[Andrew Osmond [:aosmond] (he/him)]

Yes, I agree, this should be fixed this cycle, or uplifted to beta. Originally it was just reported on SW-WR, which is not enabled on Mac, but if it affects HW-WR, it is more concerning.

Comment 15

[Jamie Nicol [:jnicol]]

I can reproduce this fairly easily on android by zooming on a text heavy page. Or on desktop on https://www.oneplus.com/uk/nord by moving the mouse over the animated menu items. Both of which would cause more texture cache allocation for new glyphs.

Comment 16

[Albert Scheiner [:alberts]]

Attachment: image.png

I can also replicate it reliably on the second part of Jamie's example page on macOS 10.14.6

Comment 18

[Jeff Muizelaar [:jrmuizel]]

Jamie, or Albert can you confirm the regression window?

Comment 20

[Andrew McCreight [:mccr8]]

[Tracking Requested - why for this release]: This is a noticeable visual regression that doesn't show up all of the time, but it seems to be fairly common given the large number of duplicate bugs filed.

Comment 21

[mmis1000]

This doesn't seems to be a MacOS only problem, it also happens to me on windows 10. Text glitches in this way sometimes randomly. Close and reopen the tabs fixed it sometimes.

Change the color fix it.
Change the font size also fix it.
Change the decoration also fix it.
But after you reverse these CSS style change, the corruption showed again.

It seems the font render cache or some sort like this corrupted in edge case and affect the graphic. (probably bad size calculation, bad font or something?)

Comment 22

[Jamie Nicol [:jnicol]]

Mozregression gave me this, confirming it is regressed by bug 1679751.

Note I had to test for a while before marking a commit as good, because it reproduces fairly easily most of the time but certainly not at will. So I wouldn't normally be 100% confident in the range. But given that we suspected this commit already and the dates match, it seems almost certain.

Comment 23

[Pascal Chevrel:pascalc (PTO until April 26)]

Tracking for 86. Nicolas, it seems your patches in bug 1679751 caused this regression.

Comment 24

[Nicolas Silva [:nical]]

Attachment: Bug 1683753 - Don't use the bucketed shelf allocator for glyphs. r=jrmuizel

Comment 25

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0ebc6a1d8e51
Don't use the bucketed shelf allocator for glyphs. r=jrmuizel

Comment 26

[Cosmin Sabou [:CosminS]]

Backed out for causing wrench failures.

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&resultStatus=success%2Ctestfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&fromchange=0ebc6a1d8e51381dc4831027dcd974b3abc61de8&tochange=d625de1f23c1ef23d1471f98f9fb3ff09611b229&searchStr=wrench&selectedTaskRun=HkC8dByeRRaXru0xt7J1eQ.0

Failure logs:
https://treeherder.mozilla.org/logviewer?job_id=325761330&repo=autoland
https://treeherder.mozilla.org/logviewer?job_id=325760551&repo=autoland

Backout link: https://hg.mozilla.org/integration/autoland/rev/fab947ad31b760b7c17ef58c3da0e2dfe496d44b

Comment 28

[Nicolas Silva [:nical]]

Attachment: Bug 1683753 - Adjust reftest references. r=jrmuizel

Adjustments required after texture packing changes.

Comment 29

[Nicolas Silva [:nical]]

Attachment: Bug 1683753 - Make android wrench reftests fuzzy by default. r=jrmuizel,jnicol

This adds a fuzziness of two in wrench as we do with non-wrench reftests.

Comment 30

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/be651eeda6d3
Don't use the bucketed shelf allocator for glyphs. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/df2921234c95
Make android wrench reftests fuzzy by default. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/9ecf9ce11807
Adjust reftest references. r=jrmuizel

Comment 31

[Razvan Maries]

Backed out for WebRender bustages.

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=LG2olct_QF-btdStdAY4BA.1&searchStr=linux%2Cx64%2Cwebrender%2Copt%2Cwebrender%2Cstandalone%2Cwebrender-lint-tidy%2Ctidy&revision=9ecf9ce11807ea4c30b9486de022ea20bb1745a4

Log: https://treeherder.mozilla.org/logviewer?job_id=326046645&repo=autoland&lineNumber=339

Backout: https://hg.mozilla.org/integration/autoland/rev/ef73153346d890ee181e8f6ccb062853de00a4da

Comment 32

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3468a8fbd38f
Don't use the bucketed shelf allocator for glyphs. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/53ce9813d599
Make android wrench reftests fuzzy by default. r=jrmuizel
https://hg.mozilla.org/integration/autoland/rev/3084eaaad6fa
Adjust reftest references. r=jrmuizel

Comment 34

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/3468a8fbd38f
https://hg.mozilla.org/mozilla-central/rev/53ce9813d599
https://hg.mozilla.org/mozilla-central/rev/3084eaaad6fa

Comment 35

[Nicolas Silva [:nical]]

Chris, can you confirm that the bug doesn't happen anymore on the latest nightly?

Comment 36

[Irvin (MozTW)]

I don't see it happening again in last few days.

Comment 37

[Chris Peterson [:cpeterson]]

(In reply to Nicolas Silva [:nical] from comment #35)

Chris, can you confirm that the bug doesn't happen anymore on the latest nightly?

I think this is fixed. Like Irvin, I haven't seen this bug over the last few days. I used to see it every day.