Bug 297702 - [Commands] command handler extensions are unnamed in the
editor

It now picks a better default, but it still prefers the class attribute
over the commandId attribute, so the fix is needed.
diff --git a/bundles/org.eclipse.ui/schema/handlers.exsd b/bundles/org.eclipse.ui/schema/handlers.exsd
index edcd978..62a305f 100644
--- a/bundles/org.eclipse.ui/schema/handlers.exsd
+++ b/bundles/org.eclipse.ui/schema/handlers.exsd
@@ -60,6 +60,9 @@
 
    <element name="handler">
       <annotation>
+         <appInfo>
+           <meta.element labelAttribute="commandId"/>
+         </appInfo>
          <documentation>
             &lt;p&gt;Associated a command with a handler implementation.&lt;/p&gt;
          </documentation>