src/Pure/PIDE/document.scala

           val node_name = command.node_name
           val command1 =
             Command.unparsed(command.source, theory = true, id = command.id, node_name = node_name,
               blobs_info = command.blobs_info, results = st.results, markups = st.markups)
           val state1 = copy(theories = theories - command1.id)
-          val snapshot = state1.snapshot(node_name = node_name).command_snippet(command1)
+          val snapshot = state1.command_snippet(command1)
           (snapshot, state1)
       }
 
     def assign(id: Document_ID.Version, edited: List[String], update: Assign_Update)
       : ((List[Node.Name], List[Command]), State) =

           case (edits, _) => edits
         })
 
       new Snapshot(this, version, node_name, edits, snippet_command)
     }
+
+    def command_snippet(command: Command): Snapshot =
+      snapshot().command_snippet(command)
   }
 }