847368 - "ASSERTION: Shouldn't be incomplete if availableBSize is UNCONSTRAINED." with :first-letter float and page-break-inside:avoid

Status: RESOLVED FIXED

(Core :: Layout: Block and Inline, defect)

Description

[Mats Palmgren (inactive)]

STEPS TO REPRODUCE
1. load the testcase in bug 847209 (note that it might also abort due to
   a later fatal assertion unless you have the fix for bug 847209)

ACTUAL RESULTS
###!!! ASSERTION: Shouldn't be incomplete if availableHeight is UNCONSTRAINED.: 'aReflowState.availableHeight != NS_UNCONSTRAINEDSIZE', file layout/generic/nsBlockFrame.cpp, line 1440

Comment 1

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 847368 - Reset floating first letter's reflow status before checking break-inside:avoid. r?#layout-reviewers

As the comment in the moved hunk said, a floating first letter frame's
incomplete status means that there is more content to be reflowed on the line.
If the block containing the floating first letter has break-inside:avoid
style, the old code would call SetInlineLineBreakBeforeAndReset(), and the
block's parent frame would misinterpret the status as "this block needs to be
push to the next fragment" even if we are not in a paginated environment.
Hence the assertion "Shouldn't be incomplete if availableBSize is
UNCONSTRAINED."

To fix this bug, we can reset the float's reflow status for a first letter frame
before checking ShouldAvoidBreakInside.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5c5e1891414c
Reset floating first letter's reflow status before checking break-inside:avoid. r=emilio

Comment 3

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/5c5e1891414c