477294 - "ASSERTION: bits don't correspond to style change reason" with MathML

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Jesse Ruderman]

Attachment: testcase

This assertion was added in bug 363247 and I'm hitting it a lot.

###!!! ASSERTION: bits don't correspond to style change reason: 'aIntrinsicDirty != eStyleChange || aBitToAdd == NS_FRAME_IS_DIRTY', file /Users/jruderman/central/layout/base/nsPresShell.cpp, line 3126

Comment 1

[Boris Zbarsky [:bzbarsky]]

It's an eStyleChange with NS_FRAME_HAS_DIRTY_CHILDREN, yeah.  The caller is nsMathMLContainerFrame::ReLayoutChildren (which always does eStyleChange) and its caller is nsMathMLmathBlockFrame::InsertFrames.

Comment 2

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Given that this function is marking ancestors with NS_FRAME_IS_DIRTY, it seems like it's effectively saying the frame is dirty.

Comment 3

[Boris Zbarsky [:bzbarsky]]

It's not marking ancestors of the frame it passes to FrameNeedsReflow with NS_FRAME_IS_DIRTY, though.

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Er, right... I'd looked a bit more since comment 2... but the difference seems incredibly minor, and I don't see any reason why an operation on a child frame should cause a frame many frames up the tree to get NS_FRAME_HAS_DIRTY_CHILDREN rather than NS_FRAME_IS_DIRTY.  If we need to do this much damage, we may as well be consistent about it.

Comment 5

[Boris Zbarsky [:bzbarsky]]

I could live with that, I guess.

Comment 6

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch

Comment 7

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

(Full reftests pass, although I don't know how meaningful that is for MathML dynamic change handling.)

Comment 8

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 361411 [details] [diff] [review]
patch

I think I'd be fine with a followup bug to remove those XXX comments and dirty bit sets they're about.

Comment 9

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

http://hg.mozilla.org/mozilla-central/rev/81bf5017af71

Comment 10

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Filed bug 477915 to follow up.