Don't print empty detailed assert message

diff --git a/mcs/class/System/System.Diagnostics/TraceListener.cs b/mcs/class/System/System.Diagnostics/TraceListener.cs
index f2d3c76610574efb4e4ddf214298f256b7155b32..7bb49150b5ef1210361f721d78c6cdcde1c029a8 100644 (file)
--- a/mcs/class/System/System.Diagnostics/TraceListener.cs
+++ b/mcs/class/System/System.Diagnostics/TraceListener.cs
@@ -162,7 +162,7 @@ namespace System.Diagnostics {
 
                public virtual void Fail (string message)
                {
-                       Fail (message, "");
+                       Fail (message, null);
                }
 
                public virtual void Fail (string message, string detailMessage)
@@ -170,8 +170,11 @@ namespace System.Diagnostics {
                        WriteLine ("---- DEBUG ASSERTION FAILED ----");
                        WriteLine ("---- Assert Short Message ----");
                        WriteLine (message);
-                       WriteLine ("---- Assert Long Message ----");
-                       WriteLine (detailMessage);
+                       if (detailMessage != null) {
+                               WriteLine ("---- Assert Long Message ----");
+                               WriteLine (detailMessage);
+                       }
+
                        WriteLine ("");
                }