[css-multicol] Updating definition of column-fill: auto

Replaced paragraph detailing that the column-fill property be consulted when container is height constrained. Added that min and max constraints be included.

Fixes #3224

Author: rachelandrew

css-multicol-1/Overview.bs

@@ -25,7 +25,7 @@ Link Defaults: css-color (property) color, css2 (property) max-height, css-backg
 At Risk: column-gap accepting <<length-percentage>> instead of <<length>>
 </pre>
 <pre class="link-defaults">
-spec:css22; type:dfn; text: table wrapper box
+spec:css-sizing-3; type:property; text:min-height
 </pre>
 
 <style type="text/css">
@@ -1143,25 +1143,21 @@ Filling columns</h2>
 			<wpt>
 			multicol-fill-auto-001.xht
 			multicol-fill-auto-002.xht
-			multicol-fill-auto-003.xht
 			multicol-fill-auto-block-children-001.xht
 			multicol-fill-auto-block-children-002.xht
 			multicol-fill-balance-001.xht
 			</wpt>
 	</dl>
 
-	<!--
 	In continuous contexts, this property will only be consulted if the
-	length of columns has been constrained. Otherwise, columns will
+	length of columns has been constrained in the block dimension, including min and max constraints (e.g., 'height', 'min-height', 'max-height'). Otherwise, columns will
 	automatically be balanced.
-	-->
 
-	In continuous contexts, this property does not have any effect when there are overflow columns.
+	<wpt>
+	multicol-fill-auto-003.xht
+	</wpt>
 
-	<!--
-	In fragmented contexts, this property will only have
-	effect on the last fragment the multicol container appears in.
-	-->
+	In continuous contexts, this property does not have any effect when there are overflow columns.
 
 	<div class="example">
 		In this example, an article only has one short paragraph which fits
@@ -1185,12 +1181,12 @@ Filling columns</h2>
 	</div>
 
 	<div class="example">
-		In this example, column balancing is turned off:
+		In this example, column balancing is turned off, and the article has a height:
 
 		<pre highlight="css">
 		article {
 			width: 60em;
-			height: auto;
+			height: 4em;
 			columns: 4;
 			column-fill: auto;
 		}
@@ -1412,8 +1408,9 @@ Pagination and overflow outside multicol containers</h3>
 
 This appendix is <em>informative</em>.
 
-<h3 id="changes-from-20171005">Changes from the <a href="https://www.w3.org/TR/2018/WD-css-multicol-1-20180528/">Working Draft (WD) of 28 May 2018</a></h3>
+<h3 id="changes-from-20180528">Changes from the <a href="https://www.w3.org/TR/2018/WD-css-multicol-1-20180528/">Working Draft (WD) of 28 May 2018</a></h3>
 <ul>
+	<li>Added the paragraph "In continuous contexts, this property will only be consulted if the length of columns has been constrained in the block dimension, including min and max constraints (e.g., 'height', 'min-height', 'max-height'). Otherwise, columns will automatically be balanced." This paragraph (without the additional detail regarding min and max constraints) was commented out in 2012, causing an interoperability issue. Also corrected the example of content ending up all in the first column, by adding the height constraint. Resolved <a href="https://github.com/w3c/csswg-drafts/issues/3224#issuecomment-468089503">28 February 2019</a></li>
 	<li>Updated the introduction to remove mention of the benefits of multicol over using tables for layout and instead refer to the unique characteristics of multicol. Editorial change referenced in <a href="https://github.com/w3c/csswg-drafts/issues/3654">issue 3654</a>.</li>
 	<li>Changed the sentence added in the pseudo-algorithm section after the 7 Jan 2016 resolution, to refer to <em>columns</em> and not <em>tracks</em> as tracks are not defined in this specification. Resolved <a href="https://github.com/w3c/csswg-drafts/issues/3649#issuecomment-472505520">13 March 2019</a>.</li>
 	<li>Changes and clarifications to the SVG images used in the specification.</li>