Only display help aliases when there are aliases. Fixes BUKKIT-1621

src/main/java/org/bukkit/craftbukkit/help/SimpleHelpMap.java

@@ -145,7 +145,10 @@ public class SimpleHelpMap implements HelpMap {
         }
 
         // Add alias sub-index
-        addTopic(new IndexHelpTopic("Aliases", "Lists command aliases", null, Collections2.filter(helpTopics.values(), Predicates.instanceOf(CommandAliasHelpTopic.class))));
+        Collection<HelpTopic> filteredTopics = Collections2.<HelpTopic>filter(helpTopics.values(), Predicates.instanceOf(CommandAliasHelpTopic.class));
+        if (!filteredTopics.isEmpty()) {
+            addTopic(new IndexHelpTopic("Aliases", "Lists command aliases", null, filteredTopics));
+        }
 
         // Initialize plugin-level sub-topics
         Map<String, Set<HelpTopic>> pluginIndexes = new HashMap<String, Set<HelpTopic>>();