[PATCH BlueZ] client: Handle system bus setup failure

[Tim Sweetman via B4 Relay <devnull+agenttimblog.gmail.com@kernel.org>]

From: Tim Sweetman <agenttimblog@gmail.com>

g_dbus_setup_bus() returns NULL when it cannot connect to the system
bus. bluetoothctl currently passes that NULL connection to
g_dbus_attach_object_manager(), causing libdbus to abort on its
connection assertion.

Initialize a DBusError, report the connection failure, and exit cleanly
before using the connection.

Fixes: https://github.com/bluez/bluez/issues/2446
---
Tested with make check (34 tests).
---
 client/main.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/client/main.c b/client/main.c
index 069e20485..d7cecb118 100644
--- a/client/main.c
+++ b/client/main.c
@@ -4017,6 +4017,7 @@ static bool timeout_quit(void *user_data)
 int main(int argc, char *argv[])
 {
 	GDBusClient *client;
+	DBusError error;
 	int status;
 	int timeout;
 	unsigned int timeout_id;
@@ -4048,7 +4049,21 @@ int main(int argc, char *argv[])
 	else
 		auto_register_agent = g_strdup("");
 
-	dbus_conn = g_dbus_setup_bus(DBUS_BUS_SYSTEM, NULL, NULL);
+	dbus_error_init(&error);
+	dbus_conn = g_dbus_setup_bus(DBUS_BUS_SYSTEM, NULL, &error);
+	if (dbus_conn == NULL) {
+		if (dbus_error_is_set(&error)) {
+			fprintf(stderr, "Failed to connect to system bus: %s\n",
+							error.message);
+			dbus_error_free(&error);
+		} else {
+			fprintf(stderr, "Failed to connect to system bus\n");
+		}
+
+		g_free(auto_register_agent);
+		return EXIT_FAILURE;
+	}
+
 	g_dbus_attach_object_manager(dbus_conn);
 
 	bt_shell_set_env("DBUS_CONNECTION", dbus_conn);

---
base-commit: e8141342284be2a52e16565b96b513ebe1297d84
change-id: 20260828-master-e87099ea4429

Best regards,
--  
Tim Sweetman <agenttimblog@gmail.com>