1617708 - Invisible initial SVG letter with webrender on (possibly related to SVG mask?)

Status: VERIFIED FIXED

(Core :: Graphics: WebRender, defect, P3)

Description

[Mike Taylor [:miketaylr]]

STR:

1. At least on macOS, with webrender enabled, visit https://www.roomformilly.com/

Expected: The letter R in Room is visible
Actual: It's invisible

If I disable the mask that's a sibling to the path that strokes the R (<mask id="4c46b4b5-2005-4e0f-bd0d-2bb4293a8c3f" height="72.4" width="51" y=".8" x="0" maskUnits="userSpaceOnUse">), the bug disappears.

Comment 1

[Mike Taylor [:miketaylr]]

Jessie, are there known WR bugs with SVG masks, perhaps?

Comment 2

[Timothy Nikkel (:tnikkel)]

This got progressively worse with more of the R getting not drawn over time.

R -> top half of R only
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=f4e9e5429fd82f9c3787ca2d42798a2bf3d353f9&tochange=20d6f233678b8cbbfec09f85c40ae42e21263a72

top half of R only -> top half of R only and clipped on the right
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=11dc1c09bb580dfec90d93bfdf2fae386f670d0e&tochange=ba22d4def27fcbfe82f102f9562fd25eb1b4f7b2

top half of R only and clipped on the right -> no R at all
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=4fe07886a969323cee79798ec501f43882096a61&tochange=5fde2c3df6087606aed6f906ee2e8d679b3e4493

Comment 3

[Jeff Muizelaar [:jrmuizel]]

Attachment: Standalone version

Comment 4

[Jeff Muizelaar [:jrmuizel]]

Attachment: Somewhat reduced

Comment 5

[Jeff Muizelaar [:jrmuizel]]

I suspect this is caused by us not respect the DataSourceSurface() offset in the composite filter

Comment 6

[Jeff Muizelaar [:jrmuizel]]

Attachment: Bug 1617708. Make ClippedDrawTarget use destination DT.

By using the destination DT we will use the correct offset
during playback instead of the offset of the reference target.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0e08a1d7fb07
Make ClippedDrawTarget use destination DT.

Comment 8

[Jeff Muizelaar [:jrmuizel]]

Comment on attachment 9136204 [details]
Bug 1617708. Make ClippedDrawTarget use destination DT.

Beta/Release Uplift Approval Request

• User impact if declined: Some web content that uses svg masks inside of filters will render incorrectly. e.g. https://roomformilly.com
• 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): The previous code didn't make much sense. The change is pretty mechanical and it's hard to imagine a scenario where it would be less correct.
• String changes made/needed:

Comment 9

[Cristian Brindusan [:cbrindusan]]

https://hg.mozilla.org/mozilla-central/rev/0e08a1d7fb07

Comment 10

[Julien Cristau [:jcristau]]

Comment on attachment 9136204 [details]
Bug 1617708. Make ClippedDrawTarget use destination DT.

approved for 75 rc1

Comment 11

[Julien Cristau [:jcristau]]

https://hg.mozilla.org/releases/mozilla-release/rev/7a72ca975023

Comment 12

[Pulsebot]

Backout by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b2cb41800a53
Backed out changeset 0e08a1d7fb07 for likely causing performance regression bug 1625071.

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/ee6e2b8bea74
Make ClippedDrawTarget use destination DT. a=reland

Comment 14

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/ee6e2b8bea74

Comment 15

[Bogdan Maris, Desktop Test Engineering]

Reproduced the initial issue using Fx 74.0 on macOS 10.15.4, verified that the issue is no longer present using latest Nightly 76.0a1 and Fx 75.0 RC on the same platform.