dix: fix incomplete commit

The following commit turned out to be incomplete. This commit makes it
complete by removing client->lastDrawable/lastGC everywhere thus
fixing ArcticaProject/nx-libs#306 and #322

    commit e6f2f6427122dc4bc802acebf26f8cec16cd2f62
    Author: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>
    Date:   Mon Jun 20 16:45:38 2016 +0200

        dix: remove caching of drawables and graphics contexts. The security checks simply bypass the cached values so they are unused.

         Backported from X.org:

         commit 9a183d7ba50e31afa133cc03aee7991517a283ea
         Author: Eamon Walsh <ewalsh@tycho.nsa.gov>
         Date:   Tue Aug 14 11:39:26 2007 -0400

            dix: remove caching of drawables and graphics contexts.  The security checks
            simply bypass the cached values so they are unused.

         Backport to nx-libs: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

2 files changed, 5 insertions, 82 deletions

diff --git a/nx-X11/programs/Xserver/dix/dispatch.c b/nx-X11/programs/Xserver/dix/dispatch.c
index 02d5170fb..044ba1c4b 100644
--- a/nx-X11/programs/Xserver/dix/dispatch.c
+++ b/nx-X11/programs/Xserver/dix/dispatch.c
@@ -216,33 +216,6 @@ InitSelections()
 }
 #endif /* NXAGENT_SERVER */
 
-void 
-FlushClientCaches(XID id)
-{
-    int i;
-    register ClientPtr client;
-
-    client = clients[CLIENT_ID(id)];
-    if (client == NullClient)
-        return ;
-    for (i=0; i<currentMaxClients; i++)
-    {
-	client = clients[i];
-        if (client != NullClient)
-	{
-            if (client->lastDrawableID == id)
-	    {
-		client->lastDrawableID = screenInfo.screens[0]->root->drawable.id;
-		client->lastDrawable = (DrawablePtr)screenInfo.screens[0]->root;
-	    }
-            else if (client->lastGCID == id)
-	    {
-                client->lastGCID = INVALID;
-		client->lastGC = (GCPtr)NULL;
-	    }
-	}
-    }
-}
 #undef SMART_DEBUG
 
 #define SMART_SCHEDULE_DEFAULT_INTERVAL	20	    /* ms */
@@ -3629,20 +3602,7 @@ void InitClient(ClientPtr client, int i, void * ospriv)
     client->sequence = 0; 
     client->clientAsMask = ((Mask)i) << CLIENTOFFSET;
     client->clientGone = FALSE;
-    if (i)
-    {
-	client->closeDownMode = DestroyAll;
-	client->lastDrawable = (DrawablePtr)screenInfo.screens[0]->root;
-	client->lastDrawableID = screenInfo.screens[0]->root->drawable.id;
-    }
-    else
-    {
-	client->closeDownMode = RetainPermanent;
-	client->lastDrawable = (DrawablePtr)NULL;
-	client->lastDrawableID = INVALID;
-    }
-    client->lastGC = (GCPtr) NULL;
-    client->lastGCID = INVALID;
+    client->closeDownMode = i ? DestroyAll : RetainPermanent;
     client->numSaved = 0;
     client->saveSet = (SaveSetElt *)NULL;
     client->noClientException = Success;
diff --git a/nx-X11/programs/Xserver/dix/dixutils.c b/nx-X11/programs/Xserver/dix/dixutils.c
index bf925f748..3ccc90d71 100644
--- a/nx-X11/programs/Xserver/dix/dixutils.c
+++ b/nx-X11/programs/Xserver/dix/dixutils.c
@@ -210,27 +210,10 @@ CompareISOLatin1Lowered(unsigned char *s1, int s1len,
 WindowPtr
 SecurityLookupWindow(XID rid, ClientPtr client, Mask access_mode)
 {
-    WindowPtr	pWin;
-
     client->errorValue = rid;
     if(rid == INVALID)
 	return NULL;
-    if (client->trustLevel != XSecurityClientTrusted)
-	return (WindowPtr)SecurityLookupIDByType(client, rid, RT_WINDOW, access_mode);
-    if (client->lastDrawableID == rid)
-    {
-        if (client->lastDrawable->type == DRAWABLE_WINDOW)
-            return ((WindowPtr) client->lastDrawable);
-        return (WindowPtr) NULL;
-    }
-    pWin = (WindowPtr)SecurityLookupIDByType(client, rid, RT_WINDOW, access_mode);
-    if (pWin && pWin->drawable.type == DRAWABLE_WINDOW) {
-	client->lastDrawable = (DrawablePtr) pWin;
-	client->lastDrawableID = rid;
-	client->lastGCID = INVALID;
-	client->lastGC = (GCPtr)NULL;
-    }
-    return pWin;
+    return (WindowPtr)SecurityLookupIDByType(client, rid, RT_WINDOW, access_mode);
 }
 
 
@@ -241,15 +224,10 @@ SecurityLookupDrawable(XID rid, ClientPtr client, Mask access_mode)
 
     if(rid == INVALID)
 	return (void *) NULL;
-    if (client->trustLevel != XSecurityClientTrusted)
-	return (DrawablePtr)SecurityLookupIDByClass(client, rid, RC_DRAWABLE,
-						    access_mode);
-    if (client->lastDrawableID == rid)
-	return ((void *) client->lastDrawable);
     pDraw = (DrawablePtr)SecurityLookupIDByClass(client, rid, RC_DRAWABLE,
 						 access_mode);
-    if (pDraw && (pDraw->type != UNDRAWABLE_WINDOW))
-        return (void *)pDraw;
+    if ((client->trustLevel != XSecurityClientTrusted) || (pDraw && (pDraw->type != UNDRAWABLE_WINDOW)))
+	return (void *)pDraw;
     return (void *)NULL;
 }
 
@@ -279,20 +257,7 @@ LookupWindow(XID rid, ClientPtr client)
     client->errorValue = rid;
     if(rid == INVALID)
 	return NULL;
-    if (client->lastDrawableID == rid)
-    {
-        if (client->lastDrawable->type == DRAWABLE_WINDOW)
-            return ((WindowPtr) client->lastDrawable);
-        return (WindowPtr) NULL;
-    }
-    pWin = (WindowPtr)LookupIDByType(rid, RT_WINDOW);
-    if (pWin && pWin->drawable.type == DRAWABLE_WINDOW) {
-	client->lastDrawable = (DrawablePtr) pWin;
-	client->lastDrawableID = rid;
-	client->lastGCID = INVALID;
-	client->lastGC = (GCPtr)NULL;
-    }
-    return pWin;
+    return (WindowPtr)LookupIDByType(rid, RT_WINDOW);
 }
 
 
@@ -303,8 +268,6 @@ LookupDrawable(XID rid, ClientPtr client)
 
     if(rid == INVALID)
 	return (void *) NULL;
-    if (client->lastDrawableID == rid)
-	return ((void *) client->lastDrawable);
     pDraw = (DrawablePtr)LookupIDByClass(rid, RC_DRAWABLE);
     if (pDraw && (pDraw->type != UNDRAWABLE_WINDOW))
         return (void *)pDraw;