diff --git a/ChangeLog b/ChangeLog
index d252555..39b35a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2005-10-03  Johannes E. Schindelin  <Johannes.Schindelin@gmx.de>
+	* libvncserver/rfbserver.c, rfb/rfb.h: add a method to the
+	  extension struct which is called to enable pseudo encodings.
+	  This is a versatile mechanism to enable/disable custom
+	  extensions with custom clients and servers.
+
 2005-09-28  Rohit Kumar <rokumar@novell.com>
 	* examples/filetransfer.c, rfb/rfb.h, configure.ac,
 	  libvncserver/{auth,cargs,main,rfbserver,sockets}.c,
diff --git a/libvncserver/rfbserver.c b/libvncserver/rfbserver.c
index 0c25f80..4b67aa1 100644
--- a/libvncserver/rfbserver.c
+++ b/libvncserver/rfbserver.c
@@ -105,7 +105,7 @@ rfbClientListInit(rfbScreenInfoPtr rfbScreen)
 {
     if(sizeof(rfbBool)!=1) {
         /* a sanity check */
-        fprintf(stderr,"rfbBool's size is not 1 (%d)!\n",sizeof(rfbBool));
+        fprintf(stderr,"rfbBool's size is not 1 (%d)!\n",(int)sizeof(rfbBool));
 	/* we cannot continue, because rfbBool is supposed to be char everywhere */
 	exit(1);
     }
@@ -924,8 +924,22 @@ rfbProcessClientNormalMessage(rfbClientPtr cl)
 #endif
 		} else
 #endif
-		 rfbLog("rfbProcessClientNormalMessage: ignoring unknown "
-                       "encoding type %d\n", (int)enc);
+		{
+			rfbExtensionData* e;
+			for(e = cl->extensions; e;) {
+				rfbExtensionData* next = e->next;
+				if(e->extension->enablePseudoEncoding &&
+					e->extension->enablePseudoEncoding(cl,
+						e->data, (int)enc))
+					/* ext handles this encoding */
+					break;
+				e = next;
+			}
+			if(e == NULL)
+				rfbLog("rfbProcessClientNormalMessage: ignoring"
+						"unknown encoding type %d\n",
+						(int)enc);
+		}
             }
         }
 
@@ -1071,12 +1085,15 @@ rfbProcessClientNormalMessage(rfbClientPtr cl)
 
     default:
 	{
-	    rfbExtensionData* extension;
+	    rfbExtensionData *e,*next;
 
-	    for(extension=cl->extensions; extension; extension=extension->next)
-		if(extension->extension->handleMessage &&
-			extension->extension->handleMessage(cl, extension->data, &msg))
+	    for(e=cl->extensions; e;) {
+		next = e->next;
+		if(e->extension->handleMessage &&
+			e->extension->handleMessage(cl, e->data, &msg))
 		    return;
+		e = next;
+	    }
 
 	    if(cl->screen->processCustomClientMessage(cl,msg.type)) {
 		rfbLog("Warning: this program uses processCustomClientMessage, "
diff --git a/libvncserver/tightvnc-filetransfer/rfbtightserver.c b/libvncserver/tightvnc-filetransfer/rfbtightserver.c
index 825fce0..013aa2e 100644
--- a/libvncserver/tightvnc-filetransfer/rfbtightserver.c
+++ b/libvncserver/tightvnc-filetransfer/rfbtightserver.c
@@ -156,7 +156,6 @@ static void
 rfbSendAuthCaps(cl)
     rfbClientPtr cl;
 {
-    rfbBool authRequired;
     rfbAuthenticationCapsMsg caps;
     rfbCapabilityInfo caplist[MAX_AUTH_CAPS];
     int count = 0;
@@ -485,6 +484,7 @@ rfbHandleSecTypeTight(rfbClientPtr cl) {
 rfbProtocolExtension tightVncFileTransferExtension = {
 	NULL,
 	rfbTightExtensionInit,
+	NULL,
 	rfbTightExtensionMsgHandler,
 	rfbTightExtensionClientClose,
 	rfbTightUsage,
diff --git a/rfb/rfb.h b/rfb/rfb.h
index fa7d7d7..f7ba150 100644
--- a/rfb/rfb.h
+++ b/rfb/rfb.h
@@ -165,6 +165,9 @@ typedef struct _rfbProtocolExtension {
 	/* returns FALSE if extension should be deactivated for client.
 	   if init == NULL, it stays activated. */
 	rfbBool (*init)(struct _rfbClientRec* client, void* data);
+	/* returns TRUE if that pseudo encoding is handled by the extension */
+	rfbBool (*enablePseudoEncoding)(struct _rfbClientRec* client,
+			void* data, int encodingNumber);
 	/* returns TRUE if message was handled */
 	rfbBool (*handleMessage)(struct _rfbClientRec* client,
 				void* data,