[css-grid] Restore content-alignment condition for stretching auto tracks. w3c#5966

Author: fantasai

css-grid-1/Overview.bs

@@ -4513,7 +4513,9 @@ Find the Size of an ''fr''</h4>
 <h3 id="algo-stretch">
 Stretch <css>auto</css> Tracks</h3>
 
-	This step expands tracks that have
+	When the [=content-distribution property=] of the [=grid container=]
+	is ''justify-content/normal'' or ''justify-content/stretch'' in this axis,
+	this step expands tracks that have
 	an ''grid-template-columns/auto'' <a>max track sizing function</a>
 	by dividing any remaining positive, <a>definite</a> <a>free space</a>
 	equally amongst them.
@@ -4701,6 +4703,13 @@ Changes since the <a href="https://www.w3.org/TR/2020/CRD-css-grid-1-20201218/">
 			Made [[#auto-margins]] normative and tightened up wording,
 			since some aspects of this behavior were not otherwise defined elsewhere.
 			(part of <a href="https://github.com/w3c/csswg-drafts/issues/5923">Issue 5923</a>)
+		<li id="change-2020-content-distribution-stretch">
+			Condition [[#algo-stretch]] on the relevant [=content-distribution property=]
+			behaving as ''justify-content/stretch'';
+			this condition was lost in translation during the
+			<a href="#change-2016-stretch-algo">earlier change</a>
+			to better incorporate ''justify-content/stretch'' handling into the algorithm.
+			(<a href="https://github.com/w3c/csswg-drafts/issues/5966">Issue 5966</a>)
 	</ul>
 
 <h3 id="changes-202008">

css-grid-2/Overview.bs

@@ -5184,7 +5184,9 @@ Find the Size of an ''fr''</h4>
 <h3 id="algo-stretch">
 Stretch <css>auto</css> Tracks</h3>
 
-	This step expands tracks that have
+	When the [=content-distribution property=] of the [=grid container=]
+	is ''justify-content/normal'' or ''justify-content/stretch'' in this axis,
+	this step expands tracks that have
 	an ''grid-template-columns/auto'' <a>max track sizing function</a>
 	by dividing any remaining positive, <a>definite</a> <a>free space</a>
 	equally amongst them.
@@ -5337,6 +5339,13 @@ Changes since the <a href="https://www.w3.org/TR/2020/CRD-css-grid-2-20201218/">
 			Made [[#auto-margins]] normative and tightened up wording,
 			since some aspects of this behavior were not otherwise defined elsewhere.
 			(part of <a href="https://github.com/w3c/csswg-drafts/issues/5923">Issue 5923</a>)
+		<li id="change-2020-content-distribution-stretch">
+			Condition [[#algo-stretch]] on the relevant [=content-distribution property=]
+			behaving as ''justify-content/stretch'';
+			this condition was lost in translation during the
+			<a href="#change-2016-stretch-algo">earlier change</a>
+			to better incorporate ''justify-content/stretch'' handling into the algorithm.
+			(<a href="https://github.com/w3c/csswg-drafts/issues/5966">Issue 5966</a>)
 	</ul>
 
 <h3 id="changes-202008">