[ac] (0) Disallow spaces in IDs.

git-svn-id: http://svn.whatwg.org/webapps@881 340c8d12-0b0e-0410-8428-c7bf67bfef74

index

@@ -6345,12 +6345,16 @@ http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C%21DOCTYPE%20HTML%3E%0
   <p>The <code title=attr-id><a href="#id">id</a></code> attribute represents
    its element's unique identifier. The value must be unique in the subtree
    within which the element finds itself and must contain at least one
-   character.
+   character. The value must not contain any <a href="#space" title="space
+   character">space characters</a>.</p>
+  <!-- space characters are disallowed because space-separated lists
+  of IDs otherwise would not be able to reach all valid IDs -->
 
   <p>If the value is not the empty string, user agents must associate the
-   element with the given value (exactly) for the purposes of ID matching
-   within the subtree the element finds itself (e.g. for selectors in CSS or
-   for the <code>getElementById()</code> method in the DOM).
+   element with the given value (exactly, including any space characters) for
+   the purposes of ID matching within the subtree the element finds itself
+   (e.g. for selectors in CSS or for the <code>getElementById()</code> method
+   in the DOM).
 
   <p>Identifiers are opaque strings. Particular meanings should not be
    derived from the value of the <code title=attr-id><a

source

@@ -5026,13 +5026,17 @@ http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C%21DOCTYPE%20HTML%3E%0
   <p>The <code title="attr-id">id</code> attribute represents its
   element's unique identifier. The value must be unique in the subtree
   within which the element finds itself and must contain at least one
-  character.</p>
+  character. The value must not contain any <span title="space
+  character">space characters</span>.</p>
+
+  <!-- space characters are disallowed because space-separated lists
+  of IDs otherwise would not be able to reach all valid IDs -->
 
   <p>If the value is not the empty string, user agents must associate
-  the element with the given value (exactly) for the purposes of ID
-  matching within the subtree the element finds itself (e.g. for
-  selectors in CSS or for the <code>getElementById()</code> method in
-  the DOM).</p>
+  the element with the given value (exactly, including any space
+  characters) for the purposes of ID matching within the subtree the
+  element finds itself (e.g. for selectors in CSS or for the
+  <code>getElementById()</code> method in the DOM).</p>
 
   <p>Identifiers are opaque strings. Particular meanings should not be
   derived from the value of the <code title="attr-id">id</code>