Show the message of unexpected message boxes in wxTestingModalHook.

This is more informative than showing just the title and we can do it for the
message boxes and it's worth handling them specially just because they are so
common.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77744 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/testing.h

@@ -288,6 +288,17 @@ protected:
     // program here.
     virtual wxString DescribeUnexpectedDialog(wxDialog* dlg) const
     {
+        // Message boxes are handled specially here just because they are so
+        // ubiquitous.
+        if ( wxMessageDialog *msgdlg = dynamic_cast<wxMessageDialog*>(dlg) )
+        {
+            return wxString::Format
+                   (
+                        "A message box \"%s\"",
+                        msgdlg->GetMessage()
+                   );
+        }
+
         return wxString::Format
                (
                     "A %s with title \"%s\"",