612171 - Regression: severe scrolling glitches with GL layers

Status: RESOLVED FIXED

(Core :: Graphics, defect)

Description

[Benoit Jacob [:bjacob] (mostly away)]

Since a few days, with GL layers, scrolling often results in large parts of the content being hidden behind a large black rectangle, changing position and appearing/disappearing everytime I scroll again.

The problem only exists with layers.accelerate-all=true

Regression window:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0f17e5f1eb01&tochange=35dfd6a0ace7

CC'ing people who made possibly relevant commits in this window.

Comment 1

[Benoit Jacob [:bjacob] (mostly away)]

...and the winner is:
    http://hg.mozilla.org/mozilla-central/rev/331f67eda6de

Comment 2

[Benoit Jacob [:bjacob] (mostly away)]

Attachment: fix bug

Based on Joe's idea. When APPLE_client_storage is absent, mBackingSurface is always null, so the condition forcing to repaint everything was always true. Not sure how it resulted in these glitches, but this patch restores the former logic when that extension is absent, fixing the glitches.

Comment 3

[Joe Drew (not getting mail)]

Comment on attachment 490703 [details] [diff] [review]
fix bug

I'd prefer an if (APPLE_client_storage) instead of the ternary operator.

Comment 4

[Benoit Jacob [:bjacob] (mostly away)]

Attachment: fix bug

Here you go! Please proof-read the logic, I confirm it works here (extension absent), haven't tried with the extension present, but I have carefully reread it.

Comment 5

[Joe Drew (not getting mail)]

http://hg.mozilla.org/mozilla-central/rev/ba45d6b7fce2