forked from mirrors/gecko-dev
c564522029
Automatic update from web-platform-tests Don't allow NG layout inside a forced legacy subtree. Display types like custom layout and MathML have no legacy implementation, so we used to force LayoutNG on such subtrees, even if we were already forced by the ancestry to do legacy layout. It turns out that handling this is just too hard, at least for pre-paint. Even if we forced NG layout in a legacy subtree, CanTraversePhysicalFragments() in LayoutObject would still return false [1], and pre-paint would treat a multicol container as a legacy multicol container, even if it was NG. This won't work, because the code expects the flow thread to establish a paint layer, which is only true if it's actually a legacy multicol container. So we crashed. Instead, for such display types, just create a LayoutBlockFlow if we're inside legacy layout. These features (custom layout / MathML) will no longer work inside a legacy subtree, but that shouldn't be much of a problem, since we won't ship those until the legacy engine is gone anyway. This will break one MathML test, which has math inside an SVG foreignObject (which is a legacy layout object). See crbug.com/989916 Remove the layout tree structure expectations from two unit tests that assumed that we support NG inside of legacy. We'll now only check that they don't crash. [1] See crbug.com/1289999 - we need to prevent fragment traversal, or the number of FragmentData objects and NGPhysicalFragment objects will mismatch - pre-paint will slice tall monolithic content because it's in legacy multicol (because legacy doesn't understand what monolithic means), while NG layout has only created one NGPhysicalFragment, because it's monolithic. Bug: 1291449, 1296664 Change-Id: I3ebd38ccff578884678b3edeacdf482e57de7b1f Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3461697 Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org> Reviewed-by: Oriol Brufau <obrufau@igalia.com> Commit-Queue: Morten Stenshorne <mstensho@chromium.org> Cr-Commit-Position: refs/heads/main@{#970937} -- wpt-commits: 2c6485bc2c46775f044b5c704d6ff61683b529d7 wpt-pr: 32840
11 lines
407 B
HTML
11 lines
407 B
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<!DOCTYPE html>
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<link rel="author" title="Morten Stenshorne" href="mailto:mstensho@chromium.org">
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<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1291449">
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<div style="columns:2;">
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<div style="display:flex;"></div>
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<div style="display:grid;"></div>
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<div style="display:table;"></div>
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<div style="display:layout(foo);">
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<div style="columns:2;"></div>
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</div>
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</div>
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