diff -r 35d45feccbc6 -r 1ce1b19f78f4 src/Pure/System/isabelle_process.scala
--- a/src/Pure/System/isabelle_process.scala	Fri May 21 12:59:44 2010 +0200
+++ b/src/Pure/System/isabelle_process.scala	Fri May 21 14:53:19 2010 +0200
@@ -84,7 +84,7 @@
 
   class Result(val kind: Kind.Value, val props: List[(String, String)], val body: List[XML.Tree])
   {
-    def message = XML.Elem(Markup.MESSAGE, (Markup.CLASS, Kind.markup(kind)) :: props, body)
+    def message = Output.Message(Kind.markup(kind), props, body)
 
     override def toString: String =
     {