1301881 - Investigate whether AddStateBits(NS_BLOCK_FLOAT_MGR) is needed in nsMathMLmathBlockFrame's constructor

Status: NEW

(Core :: MathML, defect, P5)

Description

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

My refactor of NS_NewMathMLmathBlockFrame in bug 1301630 exposes a issue that 
AddStateBits(NS_BLOCK_FLOAT_MGR) set in nsMathMLmathBlockFrame's constructor is cleared in some cases. See bug 1301630 comment 5.

We'd better investigate whether AddStateBits(NS_BLOCK_FLOAT_MGR) is still needed per bug 1301630 comment 6.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Per bug 1301630 comment 7 this was added initially for bug 353894.  But the testcase from that bug doesn't crash or assert on trunk...

Do we no longer need the float manager thing for line layout?  It's not clear to me what the invariants around that stuff are nowadays.

Comment 2

[Frédéric Wang (:fredw)]

https://hg.mozilla.org/mozilla-central/rev/76176850979d07028e80014ecbf6c51358c29b1b made NS_NewMathMLmathBlockFrame set that flag again and aFAIK that's the only way to create a nsMathMLmathBlockFrame.