Changed existing connection return code to EEXIST from 0

git-svn-id: svn+ssh://jackaudio.org/trunk/jack@509 0c269be4-1314-0410-8aa9-9f06e86f4224

configure.in

@@ -14,7 +14,7 @@ dnl                 changes are made
 dnl ---
 JACK_MAJOR_VERSION=0
 JACK_MINOR_VERSION=81
-JACK_MICRO_VERSION=4
+JACK_MICRO_VERSION=5
 
 dnl ---
 dnl HOWTO: updating the jack protocal version

jack/jack.h

@@ -447,7 +447,8 @@ int jack_port_monitoring_input (jack_port_t *port);
  * @pre The flags of the source port must include PortIsOutput.
  * @pre The flags of the destination port must include PortIsInput.
  *
- * @return 0 on success, otherwise a non-zero error code
+ * @return 0 on success, EEXIST if the connection is allready made, otherwise
+ * a non-zero error code
  */
 int jack_connect (jack_client_t *,
 		  const char *source_port,

jackd/engine.c

@@ -3368,7 +3368,7 @@ jack_port_do_connect (jack_engine_t *engine,
 
 	for (it = srcport->connections; it; it = it->next) {
 		if (((jack_connection_internal_t *)it->data)->destination == dstport) {
-			return 0;
+			return EEXIST;
 		}
 	}