From 7c4baf88ea0d80236604f14ee359fb9d92cc7467 Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Mon, 30 Apr 2018 11:44:20 +0200
Subject: [PATCH] link: move all graph nodes

---
 src/pipewire/link.c    | 30 +++++++++++++++++++++++-------
 src/pipewire/private.h |  5 ++++-
 2 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/pipewire/link.c b/src/pipewire/link.c
index 98ec070c0..c6e253e8f 100644
--- a/src/pipewire/link.c
+++ b/src/pipewire/link.c
@@ -1160,6 +1160,16 @@ static const struct pw_node_events output_node_events = {
 	.async_complete = output_node_async_complete,
 };
 
+static inline void
+move_graph(struct spa_graph *dst, struct spa_graph *src)
+{
+	struct spa_graph_node *n, *t;
+	spa_list_for_each_safe(n, t, &src->nodes, link) {
+		spa_graph_node_remove(n);
+		spa_graph_node_add(dst, n);
+	}
+}
+
 static int
 do_join_graphs(struct spa_loop *loop,
 		bool async, uint32_t seq, const void *data, size_t size, void *user_data)
@@ -1178,16 +1188,22 @@ do_join_graphs(struct spa_loop *loop,
 			in_root, out_root, in_graph, out_graph);
 
 	if (in_graph != out_graph) {
-		if (SPA_FLAG_CHECK(in_graph->flags, SPA_GRAPH_FLAG_DRIVER)) {
-			pw_log_debug("link %p: out_root to in_graph", this);
-			spa_graph_node_remove(out_root);
-			spa_graph_node_add(in_graph, out_root);
+		struct spa_graph *src, *dst;
+		bool out_driver;
+
+		out_driver = SPA_FLAG_CHECK(out_graph->flags, SPA_GRAPH_FLAG_DRIVER);
+
+		if (out_driver) {
+			pw_log_debug("link %p: in_graph to out_graph", this);
+			src = in_graph;
+			dst = out_graph;
 		}
 		else {
-			pw_log_debug("link %p: in_root to out_graph", this);
-			spa_graph_node_remove(in_root);
-			spa_graph_node_add(out_graph, in_root);
+			pw_log_debug("link %p: out_graph to in_graph", this);
+			src = out_graph;
+			dst = in_graph;
 		}
+		move_graph(dst, src);
 	}
 	this->rt.link.signal = spa_graph_link_signal_node;
 	this->rt.link.signal_data = in_root;
diff --git a/src/pipewire/private.h b/src/pipewire/private.h
index e1cc5157e..738da674a 100644
--- a/src/pipewire/private.h
+++ b/src/pipewire/private.h
@@ -251,9 +251,12 @@ struct pw_node {
 	bool enabled;			/**< if the node is enabled */
 	bool active;			/**< if the node is active */
 	bool live;			/**< if the node is live */
-	bool driver;			/**< if the node drives the graph */
+	bool driver;			/**< if the node can drive the graph */
 	bool exported;			/**< if the node is exported */
 	bool remote;			/**< if the node is implemented remotely */
+	bool master;			/**< a master node is one of the driver nodes that
+					  *  is selected to drive the graph */
+
 	struct spa_clock *clock;	/**< handle to SPA clock if any */
 	struct spa_node *node;		/**< SPA node implementation */