[css-text-4] Trim smaller punctuation is closing-opening bracket pair. w3c#1668

Author: fantasai

css-text-4/Overview.bs

@@ -1291,24 +1291,20 @@ Fullwidth Punctuation Collapsing</h4>
 			Set <a>fullwidth opening punctuation</a> half-width if the previous character is
 			a <a>fullwidth opening punctuation</a>,
 			<a>fullwidth middle dot punctuation</a>,
-			<a>fullwidth closing punctuation</a>,
-			or ideographic space (U+3000).
+			or ideographic space (U+3000),
+			or if the previous character is a <a>fullwidth closing punctuation</a>
+			of an equivalent or larger 'font-size'.
 			Else set it full-width.
 		<li>
 			Set <a>fullwidth closing punctuation</a> half-width if the next character is
 			a <a>fullwidth closing punctuation</a>,
 			<a>fullwidth middle dot punctuation</a>,
-			or ideographic space (U+3000).
+			or ideographic space (U+3000),
+			or if the next character is a <a>fullwidth opening punctuation</a>
+			of a larger 'font-size'.
 			Else set it full-width.
 	</ul>
 
-	ISSUE: The above handling of closing&mdash;opening bracket pairs
-	matches [[JLREQ]]
-	but does not correctly handle the case of mismatched font sizes.
-	Earlier drafts trimmed 1/4 of each character, essentially averaging the spacing.
-	Other options are possible: use smallest, use largest, use common ancestor (like 'letter-spacing')...
-	See <a href="https://github.com/w3c/csswg-drafts/issues/1668#issuecomment-320212394">issue/discussion</a>.
-
 	<div class="example">
 		The following example table lists the punctuation pairs
 		affected by adjancent-pairs trimming.