Deal with grapheme clusters based on spaces.

Author: fantasai

css3-writing-modes/Overview.html

@@ -32,15 +32,15 @@
 
    <h1>CSS Writing Modes Module Level 3</h1>
 
-   <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 20 July 2011</h2>
+   <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 21 July 2011</h2>
 
    <dl>
     <dt>This version:
 
     <dd><a
      href="http://dev.w3.org/csswg/css3-writing-modes/">http://dev.w3.org/csswg/css3-writing-modes/</a>
      <!--
-    <dd><a href="http://www.w3.org/TR/2011/WD-css3-writing-modes-20110720">http://www.w3.org/TR/2011/ED-css3-writing-modes-20110720/</a>
+    <dd><a href="http://www.w3.org/TR/2011/WD-css3-writing-modes-20110721">http://www.w3.org/TR/2011/ED-css3-writing-modes-20110721/</a>
 -->
 
 
@@ -3151,10 +3151,19 @@ <h2 class=no-num id=character-properties>Appendix Q. Characters and
    href=vertical-typesetting-details>Vertical Typesetting Synthesis</a>, it
    is necessary to determine the properties of a grapheme cluster. For the
    purposes of CSS Writing Modes, the properties of a grapheme cluster are
-   given by its base character&#8212;except in one case: grapheme clusters
-   formed with an Enclosing Mark (Me) of the Common script are considered to
-   be Other Symbols (So) in the Common script. They are assumed to have the
-   same Unicode properties as the Replacement Character U+FFFD.
+   given by its base character&#8212;except in two cases:
+
+  <ul>
+   <li>Grapheme clusters formed with an Enclosing Mark (Me) of the Common
+    script are considered to be Other Symbols (So) in the Common script. They
+    are assumed to have the same Unicode properties as the Replacement
+    Character U+FFFD.
+
+   <li>Grapheme clusters formed with a Space Separator (Zs) as the base are
+    considered to be Modifier Symbols (Sk). They are assumed to have the same
+    East Asian Width property as the base, but take their other properties
+    from the first combining character in the sequence.
+  </ul>
 
   <h2 class=no-num id=script-orientations>Appendix B: Bi-orientational
    Transformations</h2>

css3-writing-modes/Overview.src.html

@@ -2362,11 +2362,17 @@ <h2 id="character-properties" class="no-num">Appendix Q.
     <a href="vertical-typesetting-details">Vertical Typesetting Synthesis</a>,
     it is necessary to determine the properties of a grapheme cluster.
     For the purposes of CSS Writing Modes, the properties of a grapheme
-    cluster are given by its base character&#8212;except in one case:
-    grapheme clusters formed with an Enclosing Mark (Me) of the Common
+    cluster are given by its base character&#8212;except in two cases:
+  <ul>
+    <li>Grapheme clusters formed with an Enclosing Mark (Me) of the Common
     script are considered to be Other Symbols (So) in the Common script.
     They are assumed to have the same Unicode properties as the
     Replacement Character U+FFFD.
+    <li>Grapheme clusters formed with a Space Separator (Zs) as the base
+    are considered to be Modifier Symbols (Sk). They are assumed to have
+    the same East Asian Width property as the base, but take their other
+    properties from the first combining character in the sequence.
+  </ul>
 
 <h2 class="no-num" id="script-orientations">Appendix B:
 Bi-orientational Transformations</h2>