[flex] Fix line cross-size calculation with extreme baselines.

As pointed out in: WebKit/WebKit#31376 (comment) Blink/WebKit were doing something incorrect when a baseline was outside the border-box of a flex-item. This was because we were initializing max_major_descent and max_minor_descent to zero, instead of LayoutUnit::Min(), (similar to FlexLine::max_major_ascent_ FlexLine::max_minor_ascent_). This only occurs with a single item in a flex-line. Change-Id: I4f32eb912a07247d16231451ba63e7c7a75a8b23 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5901280 Commit-Queue: Ian Kilpatrick <[email protected]> Reviewed-by: David Grogan <[email protected]> Cr-Commit-Position: refs/heads/main@{#1363827}
web-platform-tests · Oct 3, 2024 · a860f3b · a860f3b
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commit a860f3b
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/css/css-flexbox/baseline-outside-flex-item.html b/css/css-flexbox/baseline-outside-flex-item.html
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+<!DOCTYPE html>
+<link rel="help" href="https://drafts.csswg.org/css-flexbox-1/#alignment">
+<link rel="match" href="../reference/ref-filled-green-100px-square.xht" />
+<title>A baseline outside a single flex-item shouldn't affect the size of the flex-line.</title>
+<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
+<div style="display: flex; width: 100px; align-items: baseline; background: red;">
+  <div style="height: 100px; background: green; min-width: 100px;">
+     <div style="margin-top: 200px; color: transparent;">baseline</div>
+  </div>
+</div>