Open Bug 482886 Opened 15 years ago Updated 2 years ago

ASSERTION: Primary child list can have at most one frame in it

Categories

(Core :: Layout, defect)

x86
macOS
defect

Tracking

()

People

(Reporter: bzbarsky, Unassigned)

References

Details

(Keywords: assertion, regression)

This is triggered by the reftest at layout/reftests/bugs/427017-1.xhtml

The problem is that we call nsCSSFrameConstructor::ReplicateFixedFrames, which takes all the placeholders and passes them to SetInitialChildList on a CanvasFrame.  But CanvasFrame assumes it only has one principal child list child, and has an assert to that effect in SetInitialChildList().

Can we stick these placeholders on a non-principal child list?  If not, why not, and why don't the CanvasFrame assumptions bite us?
Looks like a regression from bug 243519.
Blocks: 243519
Also bug 675713. And also this testcase:

<!DOCTYPE html><html>
<style>span { position: fixed; } * { height: 1000px }</style>
<body><span></span><span></span></body>
</html>
Severity: normal → S3
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