928645 - WARNING: Frames were in different child lists??? when running reftests

Status: NEW

(Core :: Layout, defect)

Description

[Olli Pettay [:smaug][[e-mail]]]

https://tbpl.mozilla.org/php/getParsedLog.php?id=29366821&tree=Mozilla-Inbound&full=1

Comment 1

[Mats Palmgren (inactive)]

Attachment: stack

In that log file there's a single test that prints that warning (three times):
layout/reftests/bugs/427017-1.xhtml
I can reproduce it locally in Print Preview on that file.
The stack (attached) is the same for all three occurrences.

Comment 2

[Mats Palmgren (inactive)]

That test also has a few other assertions/warnings that might be related:
ASSERTION: can't mark frame dirty during reflow: '!mIsReflowing', file layout/base/nsPresShell.cpp, line 2438
ASSERTION: Primary child list can have at most one frame in it: 'aListID != kPrincipalList || aChildList.IsEmpty() || aChildList.OnlyChild()', file layout/generic/nsCanvasFrame.cpp, line 91
WARNING: Out-of-flow frame got reflowed before its placeholder: file layout/generic/nsPlaceholderFrame.cpp, line 126