1423982 - Ensure gfx.webrender.hit-test doesn't break stuff if webrender is off

Status: RESOLVED FIXED

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

Description

[Kartikaya Gupta (email:[e-mail])]

Right now if you turn on gfx.webrender.hit-test but do NOT have webrender enabled, scrolling is broken. This is because we take the path at [1] just based on the pref, and then inside that path we call GetWebRenderAPI() which will return null and so all the hit-tests will fail. We should add a gfxVars check or something there so we don't take the WR codepath when WR is not even enabled.

Not urgent since people have to go out of their way to turn on gfx.webrender.hit-test right now (it doesn't even show up in about:config, although maybe we should add it there along with this fix).

[1] https://searchfox.org/mozilla-central/rev/2e08acdf8862e68b13166970e17809a3b5d6a555/gfx/layers/apz/src/APZCTreeManager.cpp#2222

Comment 1

[Kartikaya Gupta (email:[e-mail])]

Attachment: Bug 1423982 - Only do the WR-based hit-test if WR is enabled.

Review commit: https://reviewboard.mozilla.org/r/206400/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/206400/

Comment 2

[Botond Ballo [:botond]]

Comment on attachment 8935499 [details]
Bug 1423982 - Only do the WR-based hit-test if WR is enabled.

https://reviewboard.mozilla.org/r/206400/#review212514

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9c3344dca40f
Only do the WR-based hit-test if WR is enabled. r=botond

Comment 4

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/9c3344dca40f