src/Tools/jEdit/src/theories_dockable.scala

     Swing_Thread.require()
 
     val snapshot = PIDE.session.snapshot()
 
     val iterator =
-      restriction match {
+      (restriction match {
         case Some(names) => names.iterator.map(name => (name, snapshot.version.nodes(name)))
         case None => snapshot.version.nodes.entries
-      }
+      }).filter(_._1.is_theory)
     val nodes_status1 =
       (nodes_status /: iterator)({ case (status, (name, node)) =>
           if (PIDE.thy_load.loaded_theories(name.theory)) status
           else status + (name -> Protocol.node_status(snapshot.state, snapshot.version, node)) })