src/Pure/PIDE/command.scala

--- a/src/Pure/PIDE/command.scala	Fri Dec 14 21:50:21 2012 +0100
+++ b/src/Pure/PIDE/command.scala	Fri Dec 14 23:04:35 2012 +0100
@@ -39,6 +39,8 @@
       if (this eq other) this
       else if (rep.isEmpty) other
       else (this /: other.entries)(_ + _)
+
+    override def toString: String = entries.mkString("Results(", ", ", ")")
   }