Bug 123517 - Remote Layer Tree: Lots of ASSERT(m_children.isEmpty()); on Poster Circle
Summary: Remote Layer Tree: Lots of ASSERT(m_children.isEmpty()); on Poster Circle
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: WebKit2 (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Tim Horton
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2013-10-30 11:12 PDT by Tim Horton
Modified: 2013-10-30 11:58 PDT (History)
2 users (show)

See Also:


Attachments
patch (1.35 KB, patch)
2013-10-30 11:14 PDT, Tim Horton
no flags Details | Formatted Diff | Diff
no reason not to fold it into the existing loop (1.43 KB, patch)
2013-10-30 11:50 PDT, Tim Horton
simon.fraser: review+
Details | Formatted Diff | Diff

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Description Tim Horton 2013-10-30 11:12:02 PDT
A recently added assertion discovered a bug where our dependence on undefined behavior in CA was causing the layer tree to get into a bad state. We depend on adding a sublayer which already has a parent to another layer, the sublayer is first removed from its parent layer. CA headers say this is undefined behavior (that layers should always have a nil superlayer when being added as a sublayer), but we heavily depend on it being the case.

Most of PlatformCALayerRemote behaved correctly, but setSublayers() failed to unparent the incoming layers.
Comment 1 Tim Horton 2013-10-30 11:14:17 PDT
Created attachment 215533 [details]
patch
Comment 2 Tim Horton 2013-10-30 11:50:24 PDT
Created attachment 215542 [details]
no reason not to fold it into the existing loop
Comment 3 Tim Horton 2013-10-30 11:58:06 PDT
http://trac.webkit.org/changeset/158297