Index: maven-model/src/main/mdo/maven.mdo
===================================================================
--- maven-model/src/main/mdo/maven.mdo	(revision 590272)
+++ maven-model/src/main/mdo/maven.mdo	(working copy)
@@ -3812,30 +3778,18 @@
     public boolean equals( Object o )
     {
         if ( this == o )
-        {
             return true;
-        }
 
-        if ( !( o instanceof Extension ) )
+        if ( o instanceof Extension )
         {
-            return false;
-        }
+            Extension e = (Extension) o;
 
-        Extension e = (Extension) o;
-
-        if ( !e.getArtifactId().equals( getArtifactId() ) )
-        {
-            return false;
+            return ( artifactId == e.artifactId || ( artifactId != null && artifactId.equals( e.artifactId ) ) ) &&
+                ( groupId == e.groupId || ( groupId != null && groupId.equals( e.groupId ) ) ) &&
+                ( version == e.version || ( version != null && version.equals( e.version ) ) );
         }
-        else if ( !e.getGroupId().equals( getGroupId() ) )
-        {
-            return false;
-        }
-        else if ( e.getVersion() != null ? !e.getVersion().equals( getVersion() ) : getVersion() != null )
-        {
-            return false;
-        }
-        return true;
+
+        return false;
     }
 
     /**