Investigate specified behavior for alignment-baseline on flex items
Categories
(Core :: Layout: Block and Inline, task)
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People
(Reporter: sajidanwar, Unassigned)
References
(Blocks 1 open bug)
Details
In my initial implementation for alignment-baseline, the baseline behavior applied to flex items (as the spec says it should), but the implementation seemed wrong. See Bug 2050458 which showed a specific issue; to fix, I updated the implementation to only apply to inline text boxes and atomic inline boxes.
The conclusion I reached is that Gecko only internally models a single "alignment baseline", which is used for both alignment of elements within an alignment context, but is also the baseline that is "exported" upwards to content-driven boxes. This differs from the spec's concept of a baseline set which is the set of all baselines produced by a box; the box has an alignment baseline (one of the baselines in the set) used for alignment in the alignment context, but the entire baseline set is "exported" upward.
See Comment 20 on Bug 2050458 which has an explanation of how the baseline on flex items was working incorrectly.
This bug is to determine how this is supposed to work, including whether there needs to be more full modeling of baseline sets.
Description
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