[css-grid] Fold in handling of Microsoft's SpanGroupInWhichMaxBreadthWasMadeFinite into rewritten algo. See <http://lists.w3.org/Archives/Public/www-style/2014Mar/0500.html> for explanation.

--HG--
extra : rebase_source : e74e8905ddeb03a30766d168ef0bff074c39eb23

Author: fantasai

css-grid/Overview.bs

@@ -3293,6 +3293,7 @@ Resolve Content-Based Track Sizing Functions: Second Try</h3>
 
 	<ol>
 		<li>
+			<strong>Size tracks to fit non-spanning items:</strong>
 			For each track with an intrinsic <i>track sizing function</i>,
 			consider the items in it with a span of 1:
 			<ul>
@@ -3308,32 +3309,32 @@ Resolve Content-Based Track Sizing Functions: Second Try</h3>
 					to the maximum of the items’ <i>max-size contributions</i>.
 			</ul>
 		<li>
+			<strong>Increase sizes to accommodate spanning items:</strong>
 			Next, consider the items with a span of 2
 			that do not span a track with a <i>flexible sizing function</i>:
 			<ol>
-				<li>
-					First increase the <i>base size</i> of any tracks
-					with a <i>min track sizing function</i> of ''min-content''
-					by <a href="#extra-space">distributing extra space</a>
-					as needed to any tracks with intrinsic <i>min track sizing functions</i>
-					to account for these items' <i>min-size contributions</i>.
-				<li>
-					Next increase the <i>base size</i> of any tracks
-					with a <i>min track sizing function</i> of ''max-content''
-					by <a href="#extra-space">distributing extra space</a>
-					as needed to any tracks with ''max-content'' <i>min track sizing functions</i>
+				<li><strong>For min-content minimums:</strong>
+					First increase the <i>base size</i> of tracks with
+					a <i>min track sizing function</i> of ''min-content'' or ''max-content''
+					by <a href="#extra-space">distributing extra space</a> as needed
+					account for these items' <i>min-size contributions</i>.
+				<li><strong>For max-content minimums:</strong>
+					Next continue to increase the <i>base size</i> of tracks with
+					a <i>min track sizing function</i> of ''max-content''
+					by <a href="#extra-space">distributing extra space</a> as needed
 					to account for these items' <i>max-size contributions</i>.
-				<li>
-					Third increase the <i>growth limit</i> of any tracks
-					with a <i>max track sizing function</i> of ''min-content''
-					by <a href="#extra-space">distributing extra space</a>
-					as needed to any tracks with intrinsic <i>max track sizing functions</i>
+				<li><strong>For min-content maximums:</strong>
+					Third increase the <i>growth limit</i> of tracks with
+					a <i>max track sizing function</i> of ''min-content'' or ''max-content''
+					by <a href="#extra-space">distributing extra space</a> as needed
 					to account for these items' <i>min-size contributions</i>.
-				<li>
-					Lastly increase the <i>growth limit</i> of any tracks
-					with a <i>max track sizing function</i> of ''max-content''
-					by <a href="#extra-space">distributing extra space</a>
-					as needed to any tracks with ''max-content'' <i>max track sizing functions</i>
+					Mark any tracks whose <i>growth limit</i> changed
+					from infinite to finite in this step
+					as infinitely growable for the next step.
+				<li><strong>For max-content maximums:</strong>
+					Lastly continue to increase the <i>growth limit</i> of tracks with
+					a <i>max track sizing function</i> of ''max-content''
+					by <a href="#extra-space">distributing extra space</a> as needed
 					to account for these items' <i>max-size contributions</i>.
 			</ol>
 
@@ -3352,33 +3353,34 @@ Resolve Content-Based Track Sizing Functions: Second Try</h3>
 			For each considered item,
 			<ol>
 				<li>
-					Subtract the corresponding sizes of all spanned tracks
-					from its size contribution to find the item's remaining size contribution.
+					Subtract the corresponding size (<i>base size</i> or <i>growth limit</i>) of each spanned track
+					from the item's size contribution to find the 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.
+					freezing tracks as they reach their <i>growth limits</i>.
 					<pre><var>track-size-increase</var> = max(<var>track-size-increase</var>, <var>share-of-extra-space</var>)</pre>
+					If a track is marked as infinitely growable in this phase,
+					treat its <i>growth limit</i> as infinite for this calculation.
 				<li>
-					If space remains after all tracks max out, continue to increase&hellip;
+					If space remains after all tracks are frozen,
+					unfreeze and continue to increase&hellip;
 					<ul>
 						<li>
-							when handling ''min-content'' <i>base sizes</i>,
-							any affected track that happens to also have an intrinsic <i>max track sizing function</i>;
+							when handling ''min-content'' <i>base sizes</i>:
+							any affected track that happens to also have an intrinsic <i>max track sizing function</i>,
 							else all affected tracks.
 						<li>
-							when handling ''max-content'' <i>base sizes</i>,
-							any affected track that happens to also have a ''max-content'' <i>max track sizing function</i>;
+							when handling ''max-content'' <i>base sizes</i>:
+							any affected track that happens to also have a ''max-content'' <i>max track sizing function</i>,
 							else all affected tracks.
-						<li>when handling any intrinsic <i>growth limit</i>,
+						<li>when handling any intrinsic <i>growth limit</i>:
 							all affected tracks.
 					</ul>
 				<li>
-					Update the tracks' affected <i>base sizes</i> and <i>growth limits</i>
+					Update the tracks' affected sizes
 					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,