1445789 - The pie chart on Wikipedia's Android page does not render correctly

Status: RESOLVED FIXED

(Core :: Graphics: WebRender, defect, P1)

Description

[Kevin Brosnan [Ex-Mozilla]]

Attachment: PieChart.png

When browsing to the Wikipedia Android page https://en.wikipedia.org/wiki/Android_(operating_system)#Platform_usage the pie chart is not rendered correctly. See attached screenshot

Comment 1

[Kevin Brosnan [Ex-Mozilla]]

Attachment: about:support

Comment 2

[Aria Beingessner [:Gankra]]

Attachment: actual (webrender, left) vs expected (gecko, right)

reduced test-case

Comment 3

[Aria Beingessner [:Gankra]]

Attachment: testcase.html

reduced test case html

Comment 4

[Aria Beingessner [:Gankra]]

It seems that webrender mishandles masking a curved border with another curved border using overflow:hidden.

Confirmed on macos too, so probably all platforms.

I have been told Martin is a good choice to handle this (feel free to disagree and change the assignment)

Comment 5

[Darkspirit]

Attachment: last_good_vs_first_bad.png

Comment 6

[Darkspirit]

mozregression --good 2018-01-05 --bad 2018-01-10 --pref layers.acceleration.force-enabled:true gfx.webrender.enabled:true gfx.webrender.blob-images:true image.mem.shared:true startup.homepage_welcome_url:"https://bug1445789.bmoattachments.org/attachment.cgi?id=8960797"
> 5:58.85 INFO: Last good revision: c174ef283f5561aa3cf24b1d014b5f62dcd5ccd4
> 5:58.85 INFO: First bad revision: 8ccb0e9d9bbeeed7d7e4474849debd7d21b65971
> 5:58.85 INFO: Pushlog:
> https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=c174ef283f5561aa3cf24b1d014b5f62dcd5ccd4&tochange=8ccb0e9d9bbeeed7d7e4474849debd7d21b65971

> da9b75fc0866	Kartikaya Gupta — Bug 1426116 - Update webrender to commit a422f907be948b92bf5c7003a01f7744391a795e. r=jrmuizel

Comment 7

[Martin Robinson (email:[e-mail])]

I have opened a WebRender PR for this issue here: https://github.com/servo/webrender/pull/2578

Comment 8

[Darkspirit]

Today's Nightly: bad

try build from bug 1449562 comment 1:
mozregression --repo try --launch f9fca061ae6211bfbd8591f2b2f47fd68c0a1c87 --pref gfx.webrender.all:true startup.homepage_welcome_url:"https://en.wikipedia.org/wiki/Android_(operating_system)#Platform_usage"
good