Bug 138913

Summary:	FrameSelection::selectionBounds rarely matches the painted selection highlight rect
Product:	WebKit	Reporter:	Tim Horton <thorton>
Component:	Layout and Rendering	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	bdakin, enrica, hyatt, sam, simon.fraser, webkit-bug-importer, zalan
Priority:	P2	Keywords:	InRadar
Version:	528+ (Nightly build)
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=178232
Bug Depends on:	178032
Bug Blocks:

Description Tim Horton 2014-11-20 00:11:05 PST

There are a number of places between selection painting and the rect returned by FrameSelection::selectionBounds where rounding is applied inconsistently, resulting in a rect that doesn't precisely match the painted pixels.

For example, RenderView::subtreeSelectionBounds does a 'enclosingBoundingBox', and InlineTextBox::localSelectionRect does a 'enclosingIntRect' instead of 'snapRectToDevicePixelsWithWritingDirection' (which is what happens in the painting code).

This means that FrameSnapshotting::snapshotSelection often returns a snapshot that doesn't precisely match the blue highlight. This also breaks TextIndicator's BounceAndCrossfade animation, which depends on that being true.

Comment 1 Radar WebKit Bug Importer 2014-11-20 00:37:50 PST

<rdar://problem/19041871>