Make WriteEventsToClient/WriteToClient no-op on fake or dead clients.

nx-X11/programs/Xserver/Xext/saver.c

@@ -467,8 +467,6 @@ SendScreenSaverNotify (pScreen, state, forced)
     for (pEv = pPriv->events; pEv; pEv = pEv->next)
     {
 	client = pEv->client;
-	if (client->clientGone)
-	    continue;
 	if (!(pEv->mask & mask))
 	    continue;
 	ev.type = ScreenSaverNotify + ScreenSaverEventBase;

nx-X11/programs/Xserver/Xext/security.c

@@ -310,15 +310,11 @@ SecurityDeleteAuthorization(
     {
 	/* send revocation event event */
 	ClientPtr client = rClient(pEventClient);
-
-	if (!client->clientGone)
-	{
 	xSecurityAuthorizationRevokedEvent are;
 	are.type = SecurityEventBase + XSecurityAuthorizationRevoked;
 	are.sequenceNumber = client->sequence;
 	are.authId = pAuth->id;
 	WriteEventsToClient(client, 1, (xEvent *)&are);
-	}
 	FreeResource(pEventClient->resource, RT_NONE);
     }
 

nx-X11/programs/Xserver/Xext/shape.c

@@ -969,8 +969,6 @@ SendShapeNotify (pWin, which)
     }
     for (pShapeEvent = *pHead; pShapeEvent; pShapeEvent = pShapeEvent->next) {
 	client = pShapeEvent->client;
-	if (client == serverClient || client->clientGone)
-	    continue;
 	se.type = ShapeNotify + ShapeEventBase;
 	se.kind = which;
 	se.window = pWin->drawable.id;

nx-X11/programs/Xserver/Xext/sync.c

@@ -563,18 +563,15 @@ SyncSendAlarmNotifyEvents(pAlarm)
     ane.state = pAlarm->state;
 
     /* send to owner */
-    if (pAlarm->events && !pAlarm->client->clientGone) 
+    if (pAlarm->events)
 	WriteEventsToClient(pAlarm->client, 1, (xEvent *) &ane);
 
     /* send to other interested clients */
     for (pcl = pAlarm->pEventClients; pcl; pcl = pcl->next)
     {
-	if (!pAlarm->client->clientGone)
-	{
 	ane.sequenceNumber = pcl->client->sequence;
 	WriteEventsToClient(pcl->client, 1, (xEvent *) &ane);
     }
-    }
 }
 
 

nx-X11/programs/Xserver/damageext/damageext.c

@@ -69,7 +69,6 @@ DamageExtNotify (DamageExtPtr pDamageExt, BoxPtr pBoxes, int nBoxes)
 	    ev.area.y = pBoxes[i].y1;
 	    ev.area.width = pBoxes[i].x2 - pBoxes[i].x1;
 	    ev.area.height = pBoxes[i].y2 - pBoxes[i].y1;
-	    if (!pClient->clientGone)
 	    WriteEventsToClient (pClient, 1, (xEvent *) &ev);
 	}
     }
@@ -79,7 +78,6 @@ DamageExtNotify (DamageExtPtr pDamageExt, BoxPtr pBoxes, int nBoxes)
 	ev.area.y = 0;
 	ev.area.width = pDrawable->width;
 	ev.area.height = pDrawable->height;
-	if (!pClient->clientGone)
 	WriteEventsToClient (pClient, 1, (xEvent *) &ev);
     }
     /* Composite extension marks clients with manual Subwindows as critical */

nx-X11/programs/Xserver/dix/events.c

@@ -4439,6 +4439,9 @@ WriteEventsToClient(ClientPtr pClient, int count, xEvent *events)
     xEvent    eventTo, *eventFrom;
     int       i;
 
+    if (!pClient || pClient == serverClient || pClient->clientGone)
+	return;
+
 #ifdef XKB
     if ((!noXkbExtension)&&(!XkbFilterEvents(pClient, count, events)))
 	return;

nx-X11/programs/Xserver/os/io.c

@@ -859,14 +859,16 @@ SetCriticalOutputPending(void)
 int
 WriteToClient (ClientPtr who, int count, char *buf)
 {
-    OsCommPtr oc = (OsCommPtr)who->osPrivate;
-    ConnectionOutputPtr oco = oc->output;
+    OsCommPtr oc;
+    ConnectionOutputPtr oco;
     int padBytes;
 #ifdef DEBUG_COMMUNICATION
     Bool multicount = FALSE;
 #endif
-    if (!count)
+    if (!count || !who || who == serverClient || who->clientGone)
 	return(0);
+    oc = who->osPrivate;
+    oco = oc->output;
 #ifdef DEBUG_COMMUNICATION
     {
 	char info[128];

nx-X11/programs/Xserver/xfixes/cursor.c

@@ -96,8 +96,7 @@ CursorDisplayCursor (ScreenPtr pScreen,
 	CursorCurrent = pCursor;
 	for (e = cursorEvents; e; e = e->next)
 	{
-	    if ((e->eventMask & XFixesDisplayCursorNotifyMask) &&
-		!e->pClient->clientGone)
+	    if ((e->eventMask & XFixesDisplayCursorNotifyMask))
 	    {
 		xXFixesCursorNotifyEvent	ev;
 		ev.type = XFixesEventBase + XFixesCursorNotify;

nx-X11/programs/Xserver/xfixes/select.c

@@ -79,8 +79,7 @@ XFixesSelectionCallback (CallbackListPtr *callbacks, void * data, void * args)
     for (e = selectionEvents; e; e = e->next)
     {
 	if (e->selection == selection->selection && 
-	    (e->eventMask & eventMask) &&
-	    !e->pClient->clientGone)
+	    (e->eventMask & eventMask))
 	{
 	    xXFixesSelectionNotifyEvent	ev;