[css-grid] Copy over infinite growth-limit handling rules. Still confused on one of them. :/

Author: fantasai

css-grid/Overview.bs

@@ -3472,10 +3472,13 @@ Resolve Intrinsic Track Sizes</h3>
 			For each considered item,
 			<ol>
 				<li>
-					Subtract the corresponding (non-infinite) sizes of all spanned tracks
+					Subtract the corresponding sizes of all spanned tracks
 					from its size contribution to find the item's remaining size contribution.
+					(For infinite <i>growth limits</i>, use the track's <i>base size</i> instead.)
 					This is the space to distribute.
 					<pre><var>extra-space</var> = <var>size-contribution</var> - ∑<var>track-sizes</var></pre>
+					<p class="issue">The MS algorithm treats things that were infinity (and are no longer) specially here.
+					Don't yet understand why.
 				<li>
 					Distribute the space equally to the tracked increase of each spanned track with an affected size,
 					freezing maxed-out tracks as they hit their maximums.
@@ -3498,6 +3501,8 @@ Resolve Intrinsic Track Sizes</h3>
 					Update the tracks' affected <i>base sizes</i> and <i>growth limits</i>
 					by folding in the calculated increase
 					so that the next round of space distribution will account for the increase.
+					(If the <i>growth limit</i> is infinite,
+					set it to the track's <i>base size</i> plus the calculated increase.)
 			</ol>
 	</ol>
 

css-grid/Overview.html

@@ -3446,10 +3446,13 @@ <h3 class="heading settled heading" data-level=12.1 id=resolve-intrinsic><span c
 <p>			For each considered item,
 			<ol>
 				<li>
-					Subtract the corresponding (non-infinite) sizes of all spanned tracks
+					Subtract the corresponding sizes of all spanned tracks
 					from its size contribution to find the item’s remaining size contribution.
+					(For infinite <a data-link-type=dfn href=#growth-limit title="growth limits">growth limits</a>, use the track’s <a data-link-type=dfn href=#base-size title="base size">base size</a> instead.)
 					This is the space to distribute.
-<pre><var>extra-space</var> = <var>size-contribution</var> - ∑<var>track-sizes</var></pre>				<li>
+<pre><var>extra-space</var> = <var>size-contribution</var> - ∑<var>track-sizes</var></pre>					<p class=issue id=issue-28cbdbc2><a class=self-link href=#issue-28cbdbc2></a>The MS algorithm treats things that were infinity (and are no longer) specially here.
+					Don’t yet understand why.
+				<li>
 					Distribute the space equally to the tracked increase of each spanned track with an affected size,
 					freezing maxed-out tracks as they hit their maximums.
 <pre><var>track-size-increase</var> = max(<var>track-size-increase</var>, <var>share-of-extra-space</var>)</pre>				<li>
@@ -3470,6 +3473,8 @@ <h3 class="heading settled heading" data-level=12.1 id=resolve-intrinsic><span c
 					Update the tracks' affected <a data-link-type=dfn href=#base-size title="base sizes">base sizes</a> and <a data-link-type=dfn href=#growth-limit title="growth limits">growth limits</a>
 					by folding in the calculated increase
 					so that the next round of space distribution will account for the increase.
+					(If the <a data-link-type=dfn href=#growth-limit title="growth limit">growth limit</a> is infinite,
+					set it to the track’s <a data-link-type=dfn href=#base-size title="base size">base size</a> plus the calculated increase.)
 			</ol>
 	</ol>
 
@@ -3877,7 +3882,9 @@ <h2 class="no-num heading settled" id=issues-index><span class=content>Issues In
 		same as how Flexbox does it.
 
 
-<a href=#issue-55d6dc75> ↵ </a></div><div class=issue>
+<a href=#issue-55d6dc75> ↵ </a></div><div class=issue>The MS algorithm treats things that were infinity (and are no longer) specially here.
+					Don’t yet understand why.
+				<a href=#issue-28cbdbc2> ↵ </a></div><div class=issue>
 		Fill this in.
 
 <a href=#issue-64ae91a4> ↵ </a></div></div>