740303 - Checkerboarding is sometimes black

Status: VERIFIED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Adrian Tamas (:AdrianT)]

Attachment: Logs

Fennec/14.0a1 2012-03-28
Device: Motorola Droid 2 (Android 2.3.3)

Steps to reproduce:
1. Open Nightly.
2. Go to cnn.com or nytimes.com.
3. Zoom in and pan around the page.

Expected results:
The pan can be panned without creating visual artifacts.

Actual results:
A black screen flickers from time to time. 
Looking through the log I can see these message when the flicker occurs:

03-29 12:38:03.257: D/GeckoPanZoomController(3941): generating valid viewport using v=RectF(1171.5087, 366.65762, 1651.5094, 1110.6572) p=(1648.0,5446.0005) z=1.6093855
03-29 12:38:03.257: D/GeckoPanZoomController(3941): generated valid viewport as v=RectF(1167.9993, 366.65762, 1648.0, 1110.6572) p=(1648.0,5446.0005) z=1.6093855
03-29 12:38:03.335: I/Gecko(3941): Compositor: Composite took 91 ms.
03-29 12:38:03.343: I/GeckoSubdocumentScrollHelper(3941): Got message: Gesture:ScrollAck
03-29 12:38:03.518: D/GeckoPanZoomController(3941): Finishing animation at org.mozilla.gecko.gfx.ImmutableViewportMetrics@405d3df8

Comment 1

[Adrian Tamas (:AdrianT)]

May be related to Bug 735279

Comment 3

[Johnathan Nightingale [:johnath]]

Discussed in triage - joe thinks this is actually an issue with checkerboards being painted black in some cases. Morphing and blocking.

Comment 4

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

bug 741692 sounds like the original issue in this bug.

Comment 5

[Jeff Muizelaar [:jrmuizel]]

Attachment: Make sure we update the checkerboard layer

Presumably this started happening after we stopped setting the checkerboard color all of the time.

Comment 6

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

Comment on attachment 612684 [details] [diff] [review]
Make sure we update the checkerboard layer

Review of attachment 612684 [details] [diff] [review]:
-----------------------------------------------------------------

As discussed in person, the fix should involve rearranging of code in the updateCheckerboardLayer function instead. Good catch though :)

Comment 7

[Jeff Muizelaar [:jrmuizel]]

Attachment: Make sure we update the checkerboard layer

This moves the call to Layer::update() out of updateCheckerboardLayer() into begin drawing for better symmetry with the other calls to Layer::update() it also includes the return value of update() in mUpdated. Finally, it renames updateCheckerboardLayer to updateCheckerboardImage() to better reflect what it does.

Comment 8

[Jeff Muizelaar [:jrmuizel]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/575db34e1239

Comment 9

[(no longer active)]

https://hg.mozilla.org/mozilla-central/rev/575db34e1239

Comment 10

[Adrian Tamas (:AdrianT)]

Verified/fixed on:
Nightly Fennec 15.0a1 (2012-04-25)
Device: HTC Desire (Android 2.2.2)