[ac] (0) Require the label='' attribute on <command>, since without i…

…t the element is essentially useless.

git-svn-id: http://svn.whatwg.org/webapps@4575 340c8d12-0b0e-0410-8428-c7bf67bfef74

complete.html

@@ -42939,7 +42939,9 @@ <h4 id=the-command><span class=secno>4.11.2 </span>The <dfn><code>command</code>
    <dd><p>The element <a href=#represents>represents</a> a selection of one item from a list of items.</dd>
 
   </dl><p>The <dfn id=attr-command-label title=attr-command-label><code>label</code></dfn>
-  attribute gives the name of the command, as shown to the user.</p>
+  attribute gives the name of the command, as shown to the user. The
+  <code title=attr-command-label><a href=#attr-command-label>label</a></code> attribute must be
+  specified and must have a value that is not the empty string.</p>
 
   <p>The <dfn id=attr-command-title title=attr-command-title><code>title</code></dfn>
   attribute gives a hint describing the command, which might be shown

index

@@ -42804,7 +42804,9 @@ interface <dfn>DataGridListener</dfn> {
    <dd><p>The element <a href=#represents>represents</a> a selection of one item from a list of items.</dd>
 
   </dl><p>The <dfn id=attr-command-label title=attr-command-label><code>label</code></dfn>
-  attribute gives the name of the command, as shown to the user.</p>
+  attribute gives the name of the command, as shown to the user. The
+  <code title=attr-command-label><a href=#attr-command-label>label</a></code> attribute must be
+  specified and must have a value that is not the empty string.</p>
 
   <p>The <dfn id=attr-command-title title=attr-command-title><code>title</code></dfn>
   attribute gives a hint describing the command, which might be shown

source

@@ -47658,7 +47658,9 @@ interface <dfn>DataGridListener</dfn> {
   </dl>
 
   <p>The <dfn title="attr-command-label"><code>label</code></dfn>
-  attribute gives the name of the command, as shown to the user.</p>
+  attribute gives the name of the command, as shown to the user. The
+  <code title="attr-command-label">label</code> attribute must be
+  specified and must have a value that is not the empty string.</p>
 
   <p>The <dfn title="attr-command-title"><code>title</code></dfn>
   attribute gives a hint describing the command, which might be shown