Bug 135227 - [WK2] Fixed/Sticky layers can get mispositioned when the layer tree commit change their position or size
Summary: [WK2] Fixed/Sticky layers can get mispositioned when the layer tree commit ch...
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: New Bugs (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Benjamin Poulain
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-07-23 21:38 PDT by Benjamin Poulain
Modified: 2014-07-24 15:26 PDT (History)
6 users (show)

See Also:


Attachments
Patch (14.45 KB, patch)
2014-07-23 21:54 PDT, Benjamin Poulain
simon.fraser: review+
Details | Formatted Diff | Diff

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Description Benjamin Poulain 2014-07-23 21:38:26 PDT
[WK2] Fixed/Sticky layers can get mispositioned when the layer tree commit change their position or size
Comment 1 Benjamin Poulain 2014-07-23 21:54:38 PDT
Created attachment 235404 [details]
Patch
Comment 2 Benjamin Poulain 2014-07-23 21:54:52 PDT
First round.
Comment 3 Simon Fraser (smfr) 2014-07-23 22:16:47 PDT
Comment on attachment 235404 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=235404&action=review

> Source/WebCore/page/scrolling/ScrollingTree.h:134
> +    void fixedOrStickyNodeRemoved() { --m_fixedOrStickyNodeCount; }

Should assert that m_fixedOrStickyNodeCount isn't going to underflow.

> Source/WebCore/page/scrolling/mac/ScrollingTreeFixedNode.mm:50
> +    scrollingTree().fixedOrStickyNodeRemoved();

Not a huge fan of doing work like this in the destructor. I think it would be better to make more explicit didAddNode/didRemoveNode (which also enter the node in m_nodeMap), but maybe that's too risky at this point.
Comment 4 Benjamin Poulain 2014-07-24 15:26:21 PDT
Committed r171532: <http://trac.webkit.org/changeset/171532>