src/Tools/jEdit/src/raw_output_dockable.scala

 
   private val main_actor = actor {
     loop {
       react {
         case output: Isabelle_Process.Output =>
-          if (output.is_stdout || output.is_stderr)
-            Swing_Thread.later { text_area.append(XML.content(output.message)) }
+          Swing_Thread.later {
+            text_area.append(XML.content(output.message))
+            if (!output.is_stdout && !output.is_stderr) text_area.append("\n")
+          }
 
         case bad => System.err.println("Raw_Output_Dockable: ignoring bad message " + bad)
       }
     }
   }