Bluetooth: Mesh: Fix clearing model binding and subscriptions

The code for clearing model bindings and subscriptions was flawed in
that proper "cleared" entries were never stored in settings. The code
must pass 0 and NULL to settings_save_one() in case the entry is
desired to be cleared.

Signed-off-by: Johan Hedberg <[email protected]>

Author: Johan Hedberg

subsys/bluetooth/host/mesh/settings.c

@@ -1185,6 +1185,8 @@ static void store_pending_mod_bind(struct bt_mesh_model *mod, bool vnd)
 	u16_t keys[CONFIG_BT_MESH_MODEL_KEY_COUNT];
 	char path[20];
 	int i, count, err;
+	size_t len;
+	void *val;
 
 	for (i = 0, count = 0; i < ARRAY_SIZE(mod->keys); i++) {
 		if (mod->keys[i] != BT_MESH_KEY_UNUSED) {
@@ -1193,9 +1195,17 @@ static void store_pending_mod_bind(struct bt_mesh_model *mod, bool vnd)
 		}
 	}
 
+	if (count) {
+		val = keys;
+		len = count * sizeof(keys[0]);
+	} else {
+		val = NULL;
+		len = 0;
+	}
+
 	encode_mod_path(mod, vnd, "bind", path, sizeof(path));
 
-	err = settings_save_one(path, keys, count * sizeof(keys[0]));
+	err = settings_save_one(path, val, len);
 	if (err) {
 		BT_ERR("Failed to store %s value", log_strdup(path));
 	} else {
@@ -1208,16 +1218,26 @@ static void store_pending_mod_sub(struct bt_mesh_model *mod, bool vnd)
 	u16_t groups[CONFIG_BT_MESH_MODEL_GROUP_COUNT];
 	char path[20];
 	int i, count, err;
+	size_t len;
+	void *val;
 
 	for (i = 0, count = 0; i < ARRAY_SIZE(mod->groups); i++) {
 		if (mod->groups[i] != BT_MESH_ADDR_UNASSIGNED) {
 			groups[count++] = mod->groups[i];
 		}
 	}
 
+	if (count) {
+		val = groups;
+		len = count * sizeof(groups[0]);
+	} else {
+		val = NULL;
+		len = 0;
+	}
+
 	encode_mod_path(mod, vnd, "sub", path, sizeof(path));
 
-	err = settings_save_one(path, groups, count * sizeof(groups[0]));
+	err = settings_save_one(path, val, len);
 	if (err) {
 		BT_ERR("Failed to store %s value", log_strdup(path));
 	} else {