From 0c8cd4ab52557681df70e24df9072e2df7c7d6ff Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Sat, 7 May 2022 15:53:10 +0200
Subject: [PATCH] filter-chain: improve filter.graph parsing

First collect all the graph objects and then parse them in the
right order. Otherwise, we might try to parse links before the nodes if
they are first in the JSON string.

Fixes #1950
---
 src/modules/module-filter-chain.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/src/modules/module-filter-chain.c b/src/modules/module-filter-chain.c
index 1411992ec..206fec3f3 100644
--- a/src/modules/module-filter-chain.c
+++ b/src/modules/module-filter-chain.c
@@ -1903,8 +1903,9 @@ error:
  */
 static int load_graph(struct graph *graph, struct pw_properties *props)
 {
-	struct spa_json it[4];
+	struct spa_json it[3];
 	struct spa_json inputs, outputs, *pinputs = NULL, *poutputs = NULL;
+	struct spa_json nodes, *pnodes = NULL, links, *plinks = NULL;
 	const char *json, *val;
 	char key[256];
 	int res;
@@ -1925,24 +1926,18 @@ static int load_graph(struct graph *graph, struct pw_properties *props)
 
 	while (spa_json_get_string(&it[1], key, sizeof(key)) > 0) {
 		if (spa_streq("nodes", key)) {
-			if (spa_json_enter_array(&it[1], &it[2]) <= 0) {
+			if (spa_json_enter_array(&it[1], &nodes) <= 0) {
 				pw_log_error("nodes expects an array");
 				return -EINVAL;
 			}
-			while (spa_json_enter_object(&it[2], &it[3]) > 0) {
-				if ((res = load_node(graph, &it[3])) < 0)
-					return res;
-			}
+			pnodes = &nodes;
 		}
 		else if (spa_streq("links", key)) {
-			if (spa_json_enter_array(&it[1], &it[2]) <= 0) {
+			if (spa_json_enter_array(&it[1], &links) <= 0) {
 				pw_log_error("links expects an array");
 				return -EINVAL;
 			}
-			while (spa_json_enter_object(&it[2], &it[3]) > 0) {
-				if ((res = parse_link(graph, &it[3])) < 0)
-					return res;
-			}
+			plinks = &links;
 		}
 		else if (spa_streq("inputs", key)) {
 			if (spa_json_enter_array(&it[1], &inputs) <= 0) {
@@ -1960,6 +1955,20 @@ static int load_graph(struct graph *graph, struct pw_properties *props)
 		} else if (spa_json_next(&it[1], &val) < 0)
 			break;
 	}
+	if (pnodes == NULL) {
+		pw_log_error("filter.graph is missing a nodes array");
+		return -EINVAL;
+	}
+	while (spa_json_enter_object(pnodes, &it[2]) > 0) {
+		if ((res = load_node(graph, &it[2])) < 0)
+			return res;
+	}
+	if (plinks != NULL) {
+		while (spa_json_enter_object(plinks, &it[2]) > 0) {
+			if ((res = parse_link(graph, &it[2])) < 0)
+				return res;
+		}
+	}
 	return setup_graph(graph, pinputs, poutputs);
 }