session-helper: Correctly annotate use of Unix FDs in D-Bus API

This fixes compilation with GLib 2.63’s `gdbus-codegen`, which
automatically enables Unix FD support for D-Bus APIs which use the `h`
type, even if the `org.gtk.GDBus.C.UnixFD` annotation is missing.

By adding the annotation, the generated header whether using
`gdbus-codegen` 2.63 or < 2.63.

This is a slight API break in GLib, but it’s questionable about whether
flatpak should have always had the annotation.

Signed-off-by: Philip Withnall <[email protected]>

data/org.freedesktop.Flatpak.xml

@@ -41,6 +41,7 @@
  to do this. For instance for developer tools this lets you
  build flatpaks from inside a flatpak. -->
  <method name="HostCommand">
+ <annotation name="org.gtk.GDBus.C.UnixFD" value="true"/>
  <arg type='ay' name='cwd_path' direction='in'/>
  <arg type='aay' name='argv' direction='in'/>
  <arg type='a{uh}' name='fds' direction='in'/>

session-helper/flatpak-session-helper.c

@@ -201,15 +201,14 @@ child_setup_func (gpointer user_data)
 static gboolean
 handle_host_command (FlatpakDevelopment *object,
  GDBusMethodInvocation *invocation,
+ GUnixFDList *fd_list,
  const gchar *arg_cwd_path,
  const gchar *const *arg_argv,
  GVariant *arg_fds,
  GVariant *arg_envs,
  guint flags)
 {
  g_autoptr(GError) error = NULL;
- GDBusMessage *message = g_dbus_method_invocation_get_message (invocation);
- GUnixFDList *fd_list = g_dbus_message_get_unix_fd_list (message);
  ChildSetupData child_setup_data = { NULL };
  GPid pid;
  PidData *pid_data;
@@ -362,7 +361,7 @@ handle_host_command (FlatpakDevelopment *object,
  pid_data);
 
 
- flatpak_development_complete_host_command (object, invocation,
+ flatpak_development_complete_host_command (object, invocation, NULL,
  pid_data->pid);
  return TRUE;
 }