src/Tools/jEdit/src/document_model.scala

               val pending_nodes = for ((node_name, None) <- purged) yield node_name
               (open_nodes ::: touched_nodes ::: pending_nodes).map((_, Position.none))
             }
             val retain = PIDE.resources.dependencies(imports).theories.toSet
 
-            for ((node_name, Some(edits)) <- purged; if !retain(node_name); edit <- edits)
+            for ((node_name, Some(edits)) <- purged if !retain(node_name); edit <- edits)
               yield edit
           }
           else Nil
 
         val st1 = st.copy(models = st.models ++ file_edits.map(_._2) -- purge_edits.map(_._1))