382199 - "ASSERTION: Disagreement about whether it's a block or not" with table-as-root, float, absolute

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Jesse Ruderman]

Attachment: testcase

The testcase triggers two assertions on Mac trunk:

###!!! ASSERTION: wrong kind of child frame: 'aIsBlock == f->GetStyleDisplay()->IsBlockLevel()', file /Users/jruderman/trunk/mozilla/layout/generic/nsLineBox.cpp, line 71

###!!! ASSERTION: Disagreement about whether it's a block or not: 'fromLine->IsBlock() == fromLine->mFirstChild->GetStyleDisplay()->IsBlockLevel()', file /Users/jruderman/trunk/mozilla/layout/generic/nsBlockFrame.cpp, line 2278

Also, the red "absolute" block has mysterious space on the right side, as if it's trying to make room for the "float" block.

Comment 1

[Boris Zbarsky [:bzbarsky]]

I'm not sure those assertions are valid, given the code in nsLineLayout::TreatFrameAsBlock that claims that positioned/floated stuff is not a block...  Because for a table root we don't have the right containing blocks around, frames that have positioned or floated style can end up in-flow.

Now I don't know _why_ those clauses are there in TreatFrameAsBlock.  dbaron, roc, any idea?

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Presumably the intent was that nsBlockFrame::AddFrames doesn't put placeholder frames on a block line... but that's not necessary since placeholders shouldn't have these styles. This code dates back to the dawn of time so we can probably just remove it.

Comment 3

[Boris Zbarsky [:bzbarsky]]

Attachment: Sounds good

Comment 4

[Boris Zbarsky [:bzbarsky]]

It looks like most of this landed as part of the patch for bug 383551.  I'd still like to land the assert, I think.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Attachment: Just the assert

Comment 6

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Comment on attachment 270366 [details] [diff] [review]
Just the assert

r+sr=dbaron.  Sorry for the delay.

Comment 7

[Boris Zbarsky [:bzbarsky]]

Checked in the assertion.

Comment 8

[Jesse Ruderman]

Testcase checked in as a crashtest.