Allow styling 'overflow' on ::nth-fragment(), as discussed at face-to-face meeting afternoon of 2012-08-13.

Author: dbaron

css3-overflow/Overview.html

@@ -564,10 +564,14 @@ <h4 id=style-of-fragments><span class=secno>4.1.2. </span>Styling of
   </div>
 
   <p> Styling an ‘<code class=css>::nth-fragment()</code>’ pseudo-element
-   with the ‘<code class=property>overflow</code>’ property has no
-   effect; the computed value of ‘<code class=property>overflow</code>’
-   for the fragment box remains the same as the computed value of overflow
-   for the element.
+   with the ‘<code class=property>overflow</code>’ property does take
+   effect; if a <a href="#fragment-box"><i>fragment box</i></a> has a
+   computed value of ‘<code class=property>overflow</code>’ other than
+   ‘<code class=css>fragments</code>’ then that fragment box is the last
+   fragment. However, overriding ‘<code class=css>overflow</code>’ on the
+   first fragment does not cause the <a href="#fragment-box"><i>fragment
+   box</i></a> not to exist; whether there are fragment boxes at all is
+   determined by the computed value of overflow for the element.
 
   <p> Styling an ‘<code class=css>::nth-fragment()</code>’ pseudo-element
    with the ‘<code class=property>content</code>’ property has no effect;

css3-overflow/Overview.src.html

@@ -442,9 +442,14 @@ <h4 id="style-of-fragments">Styling of fragments</h4>
 
 	<p>
 		Styling an ''::nth-fragment()'' pseudo-element with the 'overflow'
-		property has no effect;
-		the computed value of 'overflow' for the fragment box
-		remains the same as the computed value of overflow for the element.
+		property does take effect;
+		if a <i>fragment box</i> has a
+		computed value of 'overflow' other than ''fragments''
+		then that fragment box is the last fragment.
+		However, overriding ''overflow'' on the first fragment
+		does not cause the <i>fragment box</i> not to exist;
+		whether there are fragment boxes at all is determined by
+		the computed value of overflow for the element.
 	</p>
 
 	<p>