Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: e60be43b44bb7a2a6dad763e6d73038aefb37ae6
https://github.com/WebKit/WebKit/commit/e60be43b44bb7a2a6dad763e6d73038aefb37ae6
Author: Alan Baradlay <[email protected]>
Date: 2026-04-13 (Mon, 13 Apr 2026)
Changed paths:
A LayoutTests/fast/flexbox/fieldset-as-flex-item-with-legend-expected.txt
A LayoutTests/fast/flexbox/fieldset-as-flex-item-with-legend.html
M Source/WebCore/rendering/RenderFlexibleBox.cpp
M Source/WebCore/rendering/RenderFlexibleBox.h
Log Message:
-----------
Fieldset with legend is too tall on first layout when it's a flex item
https://bugs.webkit.org/show_bug.cgi?id=311249
<rdar://problem/174301311>
Reviewed by Antti Koivisto.
A fieldset's legend adds extra "intrinsic border" to make room above
the CSS border. This is set during fieldset layout (layoutExcludedChildren).
When a fieldset is a flex item:
1. constructFlexLayoutItem reads border+padding (intrinsic border is 0)
2. computeFlexBaseSizeForFlexItem lays out the fieldset (intrinsic border
becomes 16px)
3. The stale border+padding from step 1 is used for the flex base size
The fix removes the mainAxisBorderAndPadding parameter from
computeFlexBaseSizeForFlexItem. It now reads border+padding after layout,
and constructFlexLayoutItem reads it after the call too.
* LayoutTests/fast/flexbox/fieldset-as-flex-item-with-legend-expected.txt:
Added.
* LayoutTests/fast/flexbox/fieldset-as-flex-item-with-legend.html: Added.
* Source/WebCore/rendering/RenderFlexibleBox.cpp:
(WebCore::RenderFlexibleBox::computeFlexBaseSizeForFlexItem):
(WebCore::RenderFlexibleBox::constructFlexLayoutItem):
* Source/WebCore/rendering/RenderFlexibleBox.h:
Canonical link: https://commits.webkit.org/311078@main
To unsubscribe from these emails, change your notification settings at
https://github.com/WebKit/WebKit/settings/notifications
