[css-flexbox-1] Clarified that the used cross size of an item is recalculated against the line's used cross size as its available space. #11784

Author: tabatkins

css-flexbox-1/Overview.bs

@@ -22,7 +22,7 @@ Former Editor: David Hyatt, formerly of Netscape Corporation, hyatt@apple.com
 Ignored Terms: auto, first formatted line, first letter
 Ignored Vars: item’s own max-content, maximum min-content among all items
 WPT Path Prefix: css/css-flexbox/
-WPT Display: open
+WPT Display: closed
 </pre>
 
 <pre class='link-defaults'>
@@ -3956,15 +3956,14 @@ Cross Size Determination</h3>
 
 		<li id='algo-stretch'>
 			<strong>Determine the used cross size of each flex item.</strong>
-			If a flex item has ''align-self: stretch'',
-			its computed cross size property is <a value for=width>auto</a>,
-			and neither of its cross-axis margins are <a value for=margin>auto</a>,
-			the used outer cross size is the used cross size of its flex line,
-			clamped according to the item's used min and max [=cross size|cross sizes=].
+			If a flex item's [=cross size=] depends on the available space
+			in the [=cross axis=],
+			recalculate its cross size using the [=flex line's=] [=cross size=]
+			(rather than the [=flex container's=]) as the available space.
 			Otherwise,
 			the used cross size is the item's <a>hypothetical cross size</a>.
 
-			If the flex item has ''align-self: stretch'',
+			If the flex item's [=cross size=] changed as a result,
 			redo layout for its contents,
 			treating this used size as its definite cross size
 			so that percentage-sized children can be resolved.
@@ -3973,9 +3972,8 @@ Cross Size Determination</h3>
 				table-as-item-cross-size.html
 			</wpt>
 
-			<p class='note'>
-				Note that this step does not affect the <a>main size</a> of the flex item,
-				even if it has a [=preferred aspect ratio=].
+			Note: This step does not affect the <a>main size</a> of the flex item,
+			even if it has a [=preferred aspect ratio=].
 	</ol>
 
 	<wpt>
@@ -5229,8 +5227,14 @@ Changes since the <a href="https://www.w3.org/TR/2025/CRD-css-flexbox-1-20251014
 </h3>
 
 	<ul>
-		<li>Defined the web-compatible intrinsic sizing algo in [[#intrinsic-main-sizes-compat]].
+		<li id="change-2025-web-compat-intrinsic">
+			Defined the web-compatible intrinsic sizing algo in [[#intrinsic-main-sizes-compat]].
 			(<a href="https://github.com/w3c/csswg-drafts/issues/8884#issuecomment-1636311498">Issue 8884</a>)
+
+		<li id="change-2025-cross-size-recalc">
+			Clarified that the used cross size of an item is recalculated
+			with the line's cross size as its available space.
+			(<a href="https://github.com/w3c/csswg-drafts/issues/11784">Issue 11784</a>)
 	</ul>
 
 <h3 id="changes-20181119">