1138001 - Weird graphics corruption with basic compositor

Status: RESOLVED WORKSFORME

(Core :: Graphics: Layers, defect)

Description

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Attachment: corruption.png

STR:
1. Visit http://ftp.mozilla.org/pub/mozilla.org/firefox/tinderbox-builds/holly-linux-debug/1425078564/holly_ubuntu32_vm-debug_test-crashtest-bm01-tests1-linux32-build0.txt.gz
2. Wait for it to load
3. Hit Ctrl-F and search for "asan"
4. Try to scroll up or down

I get all sorts of weird graphics corruption when I do this.

Comment 1

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Interestingly, the problem only happens when devPixelsPerPx = 2.0. If I set it to 1.0, the problem doesn't happen.

Comment 2

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Here is the regression range:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=2dbb3fbd7385&tochange=2cb4b5b08374

Strangely, the behavior changes over time. In earlier bad revisions, it just draws all black. In later bad revisions, it draws the corrupted text that you see in the screen capture I uploaded. I'll see if I can isolate when the change happens.

Comment 3

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Oh, and to reproduce this you need to turn on these prefs:
- layers.offmainthreadcomposition.enabled
- layers.offmainthreadcomposition.force-basic

It happens on Linux. I haven't tried Windows. It happens with or without e10s.

Comment 4

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

Oh, and of course you need to set devPixelsPerPx to 2.0.

Comment 5

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

This is the range where it switched from drawing all black to showing the corrupted text:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=e06adcf04636&tochange=661c58109d16

Comment 6

[Jonathan Watt [:jwatt]]

layers.offmainthreadcomposition.force-basic doesn't exist any more it seems. billm, can you still reproduce this?