[css-grid] Exclude items whose size depends on an intrinsically-sized track from baseline alignment, because that creates a cyclic dependency. Fixes #1365

Author: fantasai

css-grid-1/Overview.bs

@@ -3314,6 +3314,11 @@ Row-axis Alignment: the 'justify-self' and 'justify-items' properties</h3>
 		and so the 'justify-*' properties align the <a>grid items</a> horizontally.
 	</div>
 
+	If <a>baseline alignment</a> is specified on a <a>grid item</a>
+	whose size depends on the size of an intrinsically-sized track
+	(whose size is therefore dependent on the item's size, creating a cyclic dependency),
+	that item does not participate in baseline alignment,
+	and instead uses its <a>fallback alignment</a>.
 
 <h3 id='column-align'>
 Column-axis Alignment: the 'align-self' and 'align-items' properties</h3>
@@ -3324,6 +3329,12 @@ Column-axis Alignment: the 'align-self' and 'align-items' properties</h3>
 	or 'align-items' property on the <a>grid container</a>,
 	as defined in [[!CSS-ALIGN-3]].
 
+	If <a>baseline alignment</a> is specified on a <a>grid item</a>
+	whose size depends on the size of an intrinsically-sized track
+	(whose size is therefore dependent on the item's size, creating a cyclic dependency),
+	that item does not participate in baseline alignment,
+	and instead uses its <a>fallback alignment</a>.
+
 <h3 id='grid-align'>
 Aligning the Grid: the 'justify-content' and 'align-content' properties</h3>
 
@@ -3714,6 +3725,11 @@ Resolve Intrinsic Track Sizes</h3>
 			but they live in separate <a>baseline-sharing groups</a>.
 			[[CSS-ALIGN-3]]
 
+			Note: Since <a>grid items</a> whose own size
+			depends on the size of an intrinsically-sized track
+			<a href="#row-align">do not participate in baseline alignment</a>,
+			they are not shimmed.
+
 		<li>
 			<strong>Size tracks to fit non-spanning items:</strong>
 			For each track with an intrinsic <a>track sizing function</a>,