bufferevent_socket_connect{,_hostname}() missing event callback and u…

…se ret code

- When socket() failed in bufferevent_socket_connect() , the event
  callback should be called also in
  bufferevent_socket_connect_hostname().  eg. when use
  bufferevent_socket_connect_hostname() to resolve and connect an IP
  address but process have a smaller ulimit open files, socket() fails
  always but caller is not notified.

- Make bufferevent_socket_connect()'s behavior more consistent: function
  return error then no callback, function return ok then error passed by
  event callback.

Fixes: libevent#597
Closes: libevent#599
Closes: libevent#600

bufferevent_sock.c

@@ -396,7 +396,7 @@ bufferevent_socket_connect(struct bufferevent *bev,
 		fd = evutil_socket_(sa->sa_family,
 		    SOCK_STREAM|EVUTIL_SOCK_NONBLOCK, 0);
 		if (fd < 0)
-			goto done;
+			goto freesock;
 		ownfd = 1;
 	}
 	if (sa) {
@@ -446,10 +446,8 @@ bufferevent_socket_connect(struct bufferevent *bev,
 	goto done;
 
 freesock:
-	bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
 	if (ownfd)
 		evutil_closesocket(fd);
-	/* do something about the error? */
 done:
 	bufferevent_decref_and_unlock_(bev);
 	return result;
@@ -485,10 +483,10 @@ bufferevent_connect_getaddrinfo_cb(int result, struct evutil_addrinfo *ai,
 	}
 
 	/* XXX use the other addrinfos? */
-	/* XXX use this return value */
 	bufferevent_socket_set_conn_address(bev_p, ai->ai_addr, (int)ai->ai_addrlen);
 	r = bufferevent_socket_connect(bev, ai->ai_addr, (int)ai->ai_addrlen);
-	(void)r;
+	if (r < 0)
+		bufferevent_run_eventcb_(bev, BEV_EVENT_ERROR, 0);
 	bufferevent_decref_and_unlock_(bev);
 	evutil_freeaddrinfo(ai);
 }