Bug in D5's argument handler

Our "Flags 'bookmarks' for UID" handler has this code:

function flag_arg_uid(...) {
  switch ($op) {
    ...
    case 'filter':
      ...
      $query->add_table($table, true, 1, $joininfo);
      $query->add_where("$table.uid IS NOT NULL");

The $table.uid part is wrong, because it doesn't take the table number into account. Therefore the following scenario fails:

1. The admin adds the "Flags: Bookmarks" filter, configured as "Is Flaggde By ... Any User".
2. The admin adds the "Flags 'Bookmarks' for UID" argument.

The result is that the view shows all bookmarked records, regadless of the argument.

Somebody has fell victim to this bug.