Stabilize caret position in an editable plaintext by using directionality of prevous bidi paragraph. <https://www.w3.org/Bugs/Public/show_bug.cgi?id=16564>

Author: fantasai

css3-text/Overview.html

@@ -32,14 +32,14 @@
 
    <h1>CSS Text Level 3</h1>
 
-   <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 29 March 2012</h2>
+   <h2 class="no-num no-toc" id=longstatus-date>Editor's Draft 30 March 2012</h2>
 
    <dl>
     <dt>This version:
 
     <dd><a href="http://dev.w3.org/csswg/css3-text/">$Date$ (CVS
      $Revision$)</a> <!--
-    <dd><a href="http://www.w3.org/TR/2012/WD-css3-text-20120329/">http://www.w3.org/TR/2012/WD-css3-text-20120329/</a></dd>
+    <dd><a href="http://www.w3.org/TR/2012/WD-css3-text-20120330/">http://www.w3.org/TR/2012/WD-css3-text-20120330/</a></dd>
   -->
 
 
@@ -1986,7 +1986,10 @@ <h3 id=text-align><span class=secno>7.1. </span> Text Alignment: the
    href="#CSS3-WRITING-MODES"
    rel=biblioentry>[CSS3-WRITING-MODES]<!--{{!CSS3-WRITING-MODES}}--></a>,
    the inline base direction of its line boxes will be determined by the bidi
-   paragraphs it contains.
+   paragraphs it contains. In the case of an empty bidi paragraph, the
+   direction used is that of the previous bidi paragraph, or, if this is the
+   first bidi paragraph in the containing block, then the &lsquo;<code
+   class=property>direction</code>&rsquo; property is used.
 
   <div class=example>
    <p>In the following example, every other line is right-aligned:</p>

css3-text/Overview.src.html

@@ -1383,7 +1383,10 @@ <h3 id="text-align">
       this means using the containing block's computed 'direction'. However if
       containing block has ''unicode-bidi: plaintext'' [[!CSS3-WRITING-MODES]],
       the inline base direction of its line boxes will be determined by the bidi
-      paragraphs it contains.
+      paragraphs it contains. In the case of an empty bidi paragraph, the
+      direction used is that of the previous bidi paragraph, or, if this is the
+      first bidi paragraph in the containing block, then the 'direction'
+      property is used.
 
     <div class="example">
       <p>In the following example, every other line is right-aligned:</p>