Some applications probe for clipboard formats using the

trial-and-error method rather than asking for TARGETS. We
need to make sure we properly report unsupported formats
back to these.


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@5137 3789f03b-4d11-0410-bbf8-ca57d06f2519

unix/tx/TXWindow.cxx

@@ -454,6 +454,8 @@ void TXWindow::handleXEvent(XEvent* ev)
         } else if (se.target == XA_STRING) {
           if (!selectionRequest(se.requestor, se.selection, se.property))
             se.property = None;
+        } else {
+          se.property = None;
         }
       }
       XSendEvent(dpy, se.requestor, False, 0, (XEvent*)&se);