portal: Add a note about CLEAR_ENV behaviour

This seems like something to fix later, outside embargo.

Signed-off-by: Simon McVittie <[email protected]>

portal/flatpak-portal.c

@@ -990,6 +990,11 @@ handle_spawn (PortalFlatpak *object,
  fd_map[i].to = ++max_fd;
  }
 
+ /* TODO: Ideally we should let `flatpak run` inherit the portal's
+ * environment, in case e.g. a LD_LIBRARY_PATH is needed to be able
+ * to run `flatpak run`, but tell it to start from a blank environment
+ * when running the Flatpak app; but this isn't currently possible, so
+ * for now we preserve existing behaviour. */
  if (arg_flags & FLATPAK_SPAWN_FLAGS_CLEAR_ENV)
  {
  char *empty[] = { NULL };