--- a/src/Pure/Tools/debugger.ML Fri Aug 07 14:55:35 2015 +0200
+++ b/src/Pure/Tools/debugger.ML Fri Aug 07 16:15:53 2015 +0200
@@ -19,9 +19,11 @@
val _ = Session.protocol_handler "isabelle.Debugger$Handler";
fun output_message kind msg =
- Output.protocol_message
- (Markup.debugger_output (Simple_Thread.the_name ()))
- [Markup.markup (kind, Markup.serial_properties (serial ())) msg];
+ if msg = "" then ()
+ else
+ Output.protocol_message
+ (Markup.debugger_output (Simple_Thread.the_name ()))
+ [Markup.markup (kind, Markup.serial_properties (serial ())) msg];
val writeln_message = output_message Markup.writelnN;
val warning_message = output_message Markup.warningN;