prematurely abort ProcSendEvent if a ClientMsg has been fordwarded

Fixes #1065

Author: uli42

nx-X11/programs/Xserver/hw/nxagent/Events.c

@@ -224,7 +224,7 @@ ExposeQueue nxagentExposeQueue;
 
 RegionPtr nxagentRemoteExposeRegion = NULL;
 
-static void nxagentForwardRemoteExpose(void);
+static Bool nxagentForwardRemoteExpose(void);
 
 static int nxagentClipAndSendExpose(WindowPtr pWin, void * ptr);
 
@@ -4499,7 +4499,7 @@ int nxagentWaitEvents(Display *dpy, useconds_t msec)
   return 1;
 }
 
-void ForwardClientMessage(ClientPtr client, xSendEventReq *stuff)
+Bool ForwardClientMessage(ClientPtr client, xSendEventReq *stuff)
 {
     Atom netwmstate = MakeAtom("_NET_WM_STATE", strlen("_NET_WM_STATE"), False);
     Atom wmchangestate = MakeAtom("WM_CHANGE_STATE", strlen("WM_CHANGE_STATE"), False);
@@ -4542,7 +4542,7 @@ void ForwardClientMessage(ClientPtr client, xSendEventReq *stuff)
                 #endif
             }
             else
-                return; // ERROR!
+                return False; // ERROR!
 
             #ifdef DEBUG
             fprintf(stderr, "%s: window [0x%lx]\n", __func__, X.xclient.window);
@@ -4562,8 +4562,10 @@ void ForwardClientMessage(ClientPtr client, xSendEventReq *stuff)
             fprintf(stderr, "%s: send to window [0x%lx]\n", __func__, dest);
             fprintf(stderr, "%s: return Status [%d]\n", __func__, stat);
             #endif
+            return True;
         }
     }
+    return False;
 }
 
 #ifdef NX_DEBUG_INPUT

nx-X11/programs/Xserver/hw/nxagent/Events.h

@@ -222,6 +222,6 @@ int nxagentPendingEvents(Display *dpy);
 
 int nxagentWaitEvents(Display *, useconds_t msec);
 
-void ForwardClientMessage(ClientPtr client, xSendEventReq *stuff);
+Bool ForwardClientMessage(ClientPtr client, xSendEventReq *stuff);
 
 #endif /* __Events_H__ */

nx-X11/programs/Xserver/hw/nxagent/NXevents.c

@@ -427,8 +427,8 @@ ProcSendEvent(ClientPtr client)
 
     if (nxagentOption(Rootless) && stuff->event.u.u.type == ClientMessage)
     {
-        ForwardClientMessage(client, stuff);
-        return Success;
+        if (ForwardClientMessage(client, stuff))
+            return Success;
     }
 
     if (stuff -> event.u.u.type == SelectionNotify)