1648871 - SWGL crash when using debug draws

Status: RESOLVED FIXED

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

Description

[Bert Peers [:bpeers]]

Enable gfx.webrender.debug.picture-caching in a WR build, then switch to gfx.webrender.software results in a crash.

The crash is due to a number of places where we use p.impl after asserting it's not null, but this assert is not firing in release.
Short term fix is to at least not crash in the case of an unsupported shader.

Comment 1

[Bert Peers [:bpeers]]

Attachment: Bug 1648871 - debug draw crashes SWGL r=lsalzman

Guard against nullptr access of missing p.impl.
Also change LinkStatus so is_initialized is no longer true and calling
code can early out if bind_program fails.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b79319b8361e
debug draw crashes SWGL r=lsalzman

Comment 3

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/b79319b8361e

Comment 4

[Bogdan Maris, Desktop Test Engineering]

I tried to reproduce this issue using a Windows 10 machine (old nightly build from 2020.06.26) which has webrender enabled by default but after enabling gfx.webrender.debug.picture-caching then creating gfx.webrender.software I did not get any crashes. Is there a particular build I must use in order to reproduce? I saw some webrender entries in treeherder but no webrender specific build. Also do you think this is worth testing by manual QA?
I'm requesting needinfo from you since the account of the original reporter is disabled.

Comment 5

[Lee Salzman [:lsalzman]]

This does not really require QA testing.

Comment 6

[Bogdan Maris, Desktop Test Engineering]

(In reply to Lee Salzman [:lsalzman] from comment #5)

This does not really require QA testing.

Thanks for your answer, dropping qe-verify+ in this case.