1635658 - Map on covid19india.org renders with incorrect colors with WR enabled

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect)

Description

[Asif Youssuff]

Attachment: Screenshot from 2020-05-06 00-08-48.png

Initially reported on: https://www.reddit.com/r/firefox/comments/ge53s9/firefox_preview_messed_up_colors/

Steps to reproduce:

1. Ensure WR is enabled.
   1.5 Ensure that the OS color mode is "dark" (or use the color control on the bottom left of the site is is set to dark)
2. Visit www.covid19india.org

What happens:

The map of India that appears has a pink hue.

Expected result:

A more brownish hue.

2:40.91 INFO: Got as far as we can go bisecting nightlies...
2:40.91 INFO: Last good revision: 49b2a4c8be018f92d050512f9646cb3004ec1bec (2019-02-25)
2:40.91 INFO: First bad revision: 8c60d3a2fcc499bac3e232d666ff4491143085e6 (2019-02-26)
2:40.91 INFO: Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=49b2a4c8be018f92d050512f9646cb3004ec1bec&tochange=8c60d3a2fcc499bac3e232d666ff4491143085e6

Comment 1

[Asif Youssuff]

Attachment: covid19india-testcase.html

The problem is that the filter values in feColorMatrix is not applied when WebRender is enabled. See reduced test case.

Comment 2

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

:yoasif, since this bug is a regression, could you fill (if possible) the regressed_by field?
For more information, please visit auto_nag documentation.

Comment 3

[Timothy Nikkel (:tnikkel)]

Attachment: Bug 1635658. Fix how CSS filters render with webrender that are represented as component transfer when they are required to be represented as SVG filters. r?mstange

The brightness, contrast, and invert css filters are represented as component transfer filters when they required to be represented as an svg filter (ie when an element has a combination of CSS and SVG filters specified).

https://hg.mozilla.org/mozilla-central/rev/4f3360c4f104 (bug 1417699) used the value SVG_FECOMPONENTTRANSFER_TYPE_UNKNOWN for the function type in the G and B channels to specify that the R channel function should be used. As we know from https://hg.mozilla.org/mozilla-central/rev/a1ff0af83ad2 (bug 1605223) SVG_FECOMPONENTTRANSFER_TYPE_UNKNOWN is the value we get if the function is not specified, and by spec that is to be interpreted as the identity function.

To fix this use a special function type that is not exposed to content, SVG_FECOMPONENTTRANSFER_SAME_AS_R, when we want to do this optimization. And then teach the webrender filter code to understand it.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6a8f2a1a231c
Fix how CSS filters render with webrender that are represented as component transfer when they are required to be represented as SVG filters. r=mstange

Comment 5

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/6a8f2a1a231c

Comment 7

[Timothy Nikkel (:tnikkel)]

Comment on attachment 9146396 [details]
Bug 1635658. Fix how CSS filters render with webrender that are represented as component transfer when they are required to be represented as SVG filters. r?mstange

Beta/Release Uplift Approval Request

• User impact if declined: css filters combined with svg filters produces wrong color
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): small well understood fix
• String changes made/needed:

Comment 8

[Pascal Chevrel:pascalc]

Toimothy, it seems we regressed it in 67, is there a pressing reason to uplift the fix in 77 and not let it ride the 78 train to give it more bake time on nightly?

Comment 9

[Timothy Nikkel (:tnikkel)]

(In reply to Pascal Chevrel:pascalc from comment #8)

Toimothy, it seems we regressed it in 67, is there a pressing reason to uplift the fix in 77 and not let it ride the 78 train to give it more bake time on nightly?

No pressing reason, the reason I asked for uplift was because of the duplicate bug filed yesterday (bug 1637056), figured we could get this fix to users a little quicker.

Comment 10

[Pascal Chevrel:pascalc]

Comment on attachment 9146396 [details]
Bug 1635658. Fix how CSS filters render with webrender that are represented as component transfer when they are required to be represented as SVG filters. r?mstange

Low risk patch and affects enough people to have 2 bug reports, uplift approved for beta 6, thanks.

Comment 11

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/releases/mozilla-beta/rev/d7cd1e79d13a

Comment 12

[Gyula Palko[:gpalko]]

Verified-fixed on Nightly 78.0a1(20200515093304) and Beta 77.0b6(20200514211331) on win10 x64.