[fieldset] Fix fieldsets within flex by disabling simplified pass.

bfgeek · chromium-wpt-export-bot · commit 8d0064301dc2 · 2020-11-17T13:44:20.000-08:00
When flex did a 2-pass layout (once to determine the intrinsic size, and a followup to shrink - and the block-size changed, we'd just perform a simplified layout pass. The fieldset layout algorithm "stretches" its content to its block-size upfront. Due to this using the simplified layout pass resulted in an incorrect layout, never correctly sizing the anonymous fieldset content. This patch disables the simplified layout pass for fieldsets. Bug: 1149714 Change-Id: I454a65363c019240dd4b30531009a13e8b596ea4 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2544755 Reviewed-by: Kent Tamura <tkent@chromium.org> Reviewed-by: Christian Biesinger <cbiesinger@chromium.org> Reviewed-by: Morten Stenshorne <mstensho@chromium.org> Commit-Queue: Ian Kilpatrick <ikilpatrick@chromium.org> Cr-Commit-Position: refs/heads/master@{#828360}
diff --git a/css/css-flexbox/fieldset-as-item-overflow-ref.html b/css/css-flexbox/fieldset-as-item-overflow-ref.html
@@ -0,0 +1,6 @@
+<!DOCTYPE html>
+<div style="width: 100px; height: 100px; border: solid;">
+  <div style="overflow-y: scroll; max-height: 100%;">
+    <div style="height: 200px; background: green;"></div>
+  </div>
+</div>
diff --git a/css/css-flexbox/fieldset-as-item-overflow.html b/css/css-flexbox/fieldset-as-item-overflow.html
@@ -0,0 +1,9 @@
+<!DOCTYPE html>
+<link rel="help" href="https://bugs.chromium.org/p/chromium/issues/detail?id=1149714">
+<link rel="match" href="fieldset-as-item-overflow-ref.html">
+<meta name="assert" content="A fieldset element when flex-shrink is applied has scrollable overflow.">
+<div style="display: flex; flex-direction: column; width: 100px; height: 100px; border: solid;">
+  <fieldset style="margin: 0; border: none; padding: 0; overflow-y: scroll; overflow-x: hidden; flex-grow: 1;">
+    <div style="height: 200px; background: green;"></div>
+  </fieldset>
+</div>
