libvncclient: fix possible memory leak

in some parts of the code it was possible to lose track of resources. Cleaning them up fixes the possibility for memory leaks.

Author: ObermayrJohann

libvncclient/cursor.c

@@ -146,6 +146,9 @@ rfbBool HandleCursorShape(rfbClient* client,int xhot, int yhot, int width, int h
     return FALSE;
   }
 
+  if(client->rcMask)
+    free(client->rcMask);
+
   client->rcMask = malloc((size_t)width * height);
   if (client->rcMask == NULL) {
     free(client->rcSource);

libvncclient/vncviewer.c

@@ -524,6 +524,13 @@ void rfbClientCleanup(rfbClient* client) {
 	client->decompStream.msg != NULL)
       rfbClientLog("inflateEnd: %s\n", client->decompStream.msg );
   }
+
+#ifdef LIBVNCSERVER_HAVE_LIBJPEG
+  if(client->tjhnd){
+    tjDestroy(client->tjhnd);
+    client->tjhnd = NULL;
+  }
+#endif /* LIBVNCSERVER_HAVE_LIBJPEG */
 #endif
 
   if (client->ultra_buffer)
@@ -540,7 +547,8 @@ void rfbClientCleanup(rfbClient* client) {
     client->clientData = next;
   }
 
-  free(client->vncRec);
+  if(client->vncRec)
+	  free(client->vncRec);
 
   if (client->sock != RFB_INVALID_SOCKET)
     rfbCloseSocket(client->sock);
@@ -552,10 +560,16 @@ void rfbClientCleanup(rfbClient* client) {
     free(client->destHost);
   if (client->clientAuthSchemes)
     free(client->clientAuthSchemes);
+  if(client->rcSource)
+    free(client->rcSource);
+  if(client->rcMask)
+    free(client->rcMask);
 
 #ifdef LIBVNCSERVER_HAVE_SASL
   if (client->saslSecret)
     free(client->saslSecret);
+  if (client->saslconn)
+    sasl_dispose(&client->saslconn);
 #endif /* LIBVNCSERVER_HAVE_SASL */
 
 #ifdef WIN32