modules: nmake dynamic ports work in link-factory

Just making a port and adding it to a node does not make it a working
port..

Make a new node function to get a new free port, this will actually call
the implementation spa_node_add_port(), which will add the new port
which we can then pick up and use.

See #4876

src/modules/module-link-factory.c

@@ -279,28 +279,12 @@ static const struct pw_impl_link_events link_events = {
 static struct pw_impl_port *get_port(struct pw_impl_node *node, enum spa_direction direction)
 {
 	struct pw_impl_port *p;
-	struct pw_context *context = pw_impl_node_get_context(node);
-	int res;
 
 	p = pw_impl_node_find_port(node, direction, PW_ID_ANY);
 
-	if (p == NULL || pw_impl_port_is_linked(p)) {
+	if (p == NULL || pw_impl_port_is_linked(p))
-		uint32_t port_id;
+		p = pw_impl_node_get_free_port(node, direction);
 
-		port_id = pw_impl_node_get_free_port_id(node, direction);
-		if (port_id == SPA_ID_INVALID)
-			return NULL;
-
-		p = pw_context_create_port(context, direction, port_id, NULL, 0);
-		if (p == NULL)
-			return NULL;
-
-		if ((res = pw_impl_port_add(p, node)) < 0) {
-			pw_log_warn("can't add port: %s", spa_strerror(res));
-			errno = -res;
-			return NULL;
-		}
-	}
 	return p;
 }
 

src/pipewire/impl-node.c

@@ -2709,6 +2709,19 @@ error:
 	return SPA_ID_INVALID;
 }
 
+SPA_EXPORT
+struct pw_impl_port *pw_impl_node_get_free_port(struct pw_impl_node *node, enum pw_direction direction)
+{
+	uint32_t port_id = pw_impl_node_get_free_port_id(node, direction);
+	if (port_id == SPA_ID_INVALID)
+		return NULL;
+
+	spa_node_add_port(node->node, direction, port_id, NULL);
+
+	return pw_impl_node_find_port(node, direction, port_id);
+}
+
+
 static void on_state_complete(void *obj, void *data, int res, uint32_t seq)
 {
 	struct pw_impl_node *node = obj;

src/pipewire/impl-node.h

@@ -168,6 +168,8 @@ pw_impl_node_find_port(struct pw_impl_node *node, enum pw_direction direction, u
 
 /** Get a free unused port_id from the node */
 uint32_t pw_impl_node_get_free_port_id(struct pw_impl_node *node, enum pw_direction direction);
+/** Get a free unused port from the node */
+struct pw_impl_port *pw_impl_node_get_free_port(struct pw_impl_node *node, enum pw_direction direction);
 
 int pw_impl_node_initialized(struct pw_impl_node *node);