[css-grid-1] Handle clamping of auto contributions for spanning items. #2303

Author: fantasai

css-grid-1/Overview.bs

@@ -4021,11 +4021,7 @@ Resolve Intrinsic Track Sizes</h3>
 		<li id="algo-spanning-items">
 			<strong>Increase sizes to accommodate spanning items crossing content-sized tracks:</strong>
 			Next, consider the items with a span of 2
-			that do not span a track with a <a>flexible sizing function</a>,
-			treating a <a>min track sizing function</a> of ''auto''
-			as ''min-content''/''max-content''
-			when the grid container is being sized under a
-			<a lt="min-content constraint">min</a>/<a>max-content constraint</a> (respectively):
+			that do not span a track with a <a>flexible sizing function</a>.
 			<!-- auto-min contribution <= min-content contribution <= max-content contribution -->
 
 			<ol>
@@ -4035,21 +4031,45 @@ Resolve Intrinsic Track Sizes</h3>
 					an <a lt="intrinsic sizing function">intrinsic</a> <a>min track sizing function</a>
 					by <a href="#extra-space">distributing extra space</a> as needed
 					to accommodate these items’ <a>minimum contributions</a>.
+
+					If the grid container is being sized under a
+					<a lt="min-content constraint">min-</a> or <a>max-content constraint</a>,
+					use the items’ <a>limited min-content contributions</a>
+					in place of their <a>minimum contributions</a> here.
+					(For an item spanning multiple tracks,
+					the upper limit used to calculate
+					its <a lt="limited min-content contribution">limited min-/max-content contribution</a>
+					is the <em>sum</em> of the <a lt="fixed sizing function">fixed</a>
+					<a>max track sizing functions</a>
+					of any tracks it spans,
+					and is applied if it only spans such tracks.)
+
 				<li>
 					<strong>For content-based minimums:</strong>
 					Next continue to increase the <a>base size</a> of tracks with
 					a <a>min track sizing function</a> of ''min-content'' or ''max-content''
 					by <a href="#extra-space">distributing extra space</a> as needed
 					to account for these items' <a>min-content contributions</a>.
+
 				<li>
 					<strong>For max-content minimums:</strong>
-					Third continue to increase the <a>base size</a> of tracks with
+					Next, if the grid container is being sized
+					under a <a>max-content constraint</a>,
+					continue to increase the <a>base size</a> of tracks with
+					a <a>min track sizing function</a> of
+					''grid-template-columns/auto'' or ''max-content''
+					by <a href="#extra-space">distributing extra space</a> as needed
+					to account for these items' <a>limited max-content contributions</a>.
+
+					In all cases,
+					continue to increase the <a>base size</a> of tracks with
 					a <a>min track sizing function</a> of ''max-content''
 					by <a href="#extra-space">distributing extra space</a> as needed
 					to account for these items' <a>max-content contributions</a>.
 				<li>
 					If at this point any track’s <a>growth limit</a> is now less than its <a>base size</a>,
 					increase its <a>growth limit</a> to match its <a>base size</a>.
+
 				<li>
 					<strong>For intrinsic maximums:</strong>
 					Next increase the <a>growth limit</a> of tracks with
@@ -4099,6 +4119,7 @@ Resolve Intrinsic Track Sizes</h3>
 							</pre>
 						</blockquote>
 					</details>
+
 				<li>
 					<strong>For max-content maximums:</strong>
 					Lastly continue to increase the <a>growth limit</a> of tracks with

css-grid-1/issues-cr-2017.bsi

@@ -498,7 +498,7 @@ Issue 57.
 Summary:  Add note that minimum contribution <= min-content contribution
 From:     Oriol Brufau
 Comment:  https://github.com/w3c/csswg-drafts/issues/3616#issuecomment-461396941
-Changes:  https://github.com/w3c/csswg-drafts/commit/
+Changes:  https://github.com/w3c/csswg-drafts/commit/7676ea26bcedaa69835fe43b92361523b3ef5890
 Closed:   Accepted
 Resolved: Editorial
 ----

css-grid-1/issues-cr-2017.html

@@ -536,7 +536,7 @@ <h1>CSS Grid Layout Level 1 Disposition of Comments for 2017-12-14 CR</h1>
 <span>Summary:  Add note that minimum contribution &lt;= min-content contribution</span>
 <span>From:     Oriol Brufau</span>
 <span>Comment:  <a href='https://github.com/w3c/csswg-drafts/issues/3616#issuecomment-461396941'>https://github.com/w3c/csswg-drafts/issues/3616#issuecomment-461396941</a></span>
-<span>Changes:  <a href='https://github.com/w3c/csswg-drafts/commit/'>https://github.com/w3c/csswg-drafts/commit/</a></span>
+<span>Changes:  <a href='https://github.com/w3c/csswg-drafts/commit/7676ea26bcedaa69835fe43b92361523b3ef5890'>https://github.com/w3c/csswg-drafts/commit/7676ea26bcedaa69835fe43b92361523b3ef5890</a></span>
 <span class="a">Closed:   Accepted</span>
 <span>Resolved: Editorial</span></pre>
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