Index: simgear/simgear/io/sg_socket_udp.cxx
===================================================================
--- simgear.orig/simgear/io/sg_socket_udp.cxx	2013-09-06 14:40:55.564046737 -0400
+++ simgear/simgear/io/sg_socket_udp.cxx	2013-09-06 14:40:55.560046633 -0400
@@ -104,8 +104,13 @@
     }
 
     int result;
+    if ( length < 0 ) {
+   length = 0;
+    }
+    
+    int size = length < SG_IO_MAX_MSG_SIZE ? length : SG_IO_MAX_MSG_SIZE;
 
-    if ( (result = sock.recv(buf, SG_IO_MAX_MSG_SIZE, 0)) >= 0 ) {
+    if ( (result = sock.recv(buf, size, 0)) >= 0 ) {
 	buf[result] = '\0';
 	// printf("msg received = %s\n", buf);
     }