[css-overflow-3] Tweaks to max-lines

Author: frivoal

css-overflow-3/Overview.bs

@@ -450,22 +450,21 @@ Limiting Number of Visible Text Lines: the 'max-lines' property</h2>
 	remaining content is fragmented away
 	and neither rendered nor measured.
 	Specifically,
+	if the value of 'max-lines' is not <dfn for=max-lines type=value>none</dfn>:
 
 	<ul>
 		<li>The box becomes a <a>fragmentation container</a>
-			that captures <a>region breaks</a>.
+			that captures <a>region breaks</a>,
+			if it is not already.
+			[[!CSS-BREAK-3]]
 
-		<li>A <a>region break</a> [[!CSS-BREAK-3]]
+		<li>A <a>region break</a>
 			is forced after its <var>N</var>th
 			descendant <a>in-flow</a> <a>line box</a>,
 			where <var>N</var> is the specified value of 'max-lines'.
-			For this purpose,
-			line boxes are counted in
-			<span class="issue"><a>document order</a> OR
-			visual order
-			(<a>grid order</a> in <a>grid containers</a>,
-			<a>flex order</a> in <a>flex containers</a>,
-			and <a>document order</a> in all other <a>display types</a>)</span>.
+			The contents of descendants that are <a>scroll containers</a>
+			or that are not <a>block containers</a>
+			are skipped over while counting line boxes.
 
 			If fewer than <var>N</var> line boxes exist,
 			then 'max-lines' introduces no <a>region break</a>.
@@ -474,7 +473,13 @@ Limiting Number of Visible Text Lines: the 'max-lines' property</h2>
 			(whether imposed by 'max-lines' or by another mechanism,
 			such as the 'break-before'/'break-after' properties)
 			is treated as the end of the <a>fragmentation container</a>,
-			and the rest of the <a>fragmented flow</a> is discarded,
+			and the rest of the <a>fragmented flow</a> is laid out in
+			the next <a>fragmentation container</a> in the <a>fragmentation context</a>.
+
+			If there is no subsequent <a>fragmentation container</a>
+			(which is the case if the box became a <a>fragmentation container</a>
+			merely as a consequence of applying the 'max-lines' property),
+			the rest of the <a>fragmented flow</a> is discarded,
 			as if it were ''display: none'':
 			it is neither rendered,
 			nor measured as part of the box’s contents for the purpose of
@@ -495,6 +500,8 @@ Limiting Number of Visible Text Lines: the 'max-lines' property</h2>
 			differently from the rest. -->
 	</ul>
 
+	Only positive integers are accepted. Zero or negative integers are invalid.
+
 <h2 id="static-media">
 Overflow in static media</h2>