tests: Don't exercise GetMachineId() or autolaunch if no machine ID

At the moment there is a hack in the implementation of GetMachineId()
to stop tests from failing during "make check" on a system where
dbus has never been installed, by silently generating a new unique
fake "machine ID" for each process. I'm about to change that
behaviour to report errors properly; skip affected test-cases if we
can't read the real machine ID.

The shell scripts to test dbus-launch are run both as "make check"
tests (for which it is valid for dbus to be not correctly installed)
and as installed-tests (for which that is not valid), so make them
pass during "make check" but fail during installed testing.
The tests in bus/ and test/name-test/ are only run during "make check"
so they only have the code path where they are skipped.

Signed-off-by: Simon McVittie <smcv@collabora.com>
Reviewed-by: Philip Withnall <withnall@endlessm.com>
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=13194

1 files changed, 11 insertions, 0 deletions

diff --git a/bus/dispatch.c b/bus/dispatch.c
index 2b590741..19228bed 100644
--- a/bus/dispatch.c
+++ b/bus/dispatch.c
@@ -3330,10 +3330,21 @@ static dbus_bool_t
 check_existent_get_machine_id (BusContext     *context,
                                DBusConnection *connection)
 {
+  DBusError error = DBUS_ERROR_INIT;
   DBusMessage *message;
   dbus_uint32_t serial;
+  DBusGUID uuid;
   const char *machine_id;
 
+  if (!_dbus_read_local_machine_uuid (&uuid, FALSE, &error))
+    {
+      /* Unable to test further: either we ran out of memory, or neither
+       * dbus nor systemd was ever correctly installed on this machine */
+      _dbus_verbose ("Machine UUID not available: %s", error.message);
+      dbus_error_free (&error);
+      return TRUE;
+    }
+
   message = dbus_message_new_method_call (EXISTENT_SERVICE_NAME,
                                           "/org/freedesktop/TestSuite",
                                           "org.freedesktop.DBus.Peer",