src/Pure/ProofGeneral/proof_general_emacs.ML

 fun decorate bg en prfx =
   Output.writeln_default o enclose bg en o prefix_lines prfx;
 
 fun setup_messages () =
  (Output.writeln_fn := Output.writeln_default;
-  Output.status_fn := Output.writeln_default;
+  Output.status_fn := (fn "" => () | s => ! Output.priority_fn s);
   Output.priority_fn := (fn s => decorate (special "360") (special "361") "" s);
   Output.tracing_fn := (fn s => decorate (special "360" ^ special "375") (special "361") "" s);
   Output.debug_fn := (fn s => decorate (special "362") (special "363") "+++ " s);
   Output.warning_fn := (fn s => decorate (special "362") (special "363") "### " s);
   Output.error_fn := (fn s => decorate (special "364") (special "365") "*** " s);