tree 2d6288ea1a3d1920516963f7889938f84d225cae
parent 23ae23071d3c44ee4b6b5a625498229f6107a31c
author Alison Maher <almaher@microsoft.com> 1618535265 -0700
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> 1618536741 -0700

[LayoutNG] OOF positioned offset in a nested multicol

OOF positioned elements (abspos or fixedpos) in a nested multicol
could get the wrong offset if the containing block started in a column
that was not the first in a given multicol fragment. The reason being
that we had adjusted the containing block offset in CL:2680070 to take
into account columns from previous fragments. However, if the containing
block was not in the first column in a multicol fragment, we would have
already adjusted for this in NGContainerFragmentBuilder (given that its
column's builder would have access to the previous column break token).

To fix this, utilize the previous_break_token_ stored in
NGBoxFragmentBuilder (which is available in both cases above) to
determine the correct offset for the containing block. Instead of
passing both this adjustment for the containing block and a bool to
determine if we should propagate OOFs, a new base::Optional<LayoutUnit>
variable is passed into PropagateOOFPositionedInfo() to determine both
(credit: CL:2827892). This containing block adjustment is determined
in NGBoxFragmentBuilder::BlockOffsetAdjustmentForFragmentainer().

Bug: 1198578
Change-Id: I3c183dd83ed45e240fb9f62347dd388e370b1510
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2822985
Commit-Queue: Alison Maher <almaher@microsoft.com>
Reviewed-by: Morten Stenshorne <mstensho@chromium.org>
Cr-Commit-Position: refs/heads/master@{#873126}