nCount == 5 is impossible; the grammar has changed since this code was written.
It used to refer to case '(' joined_table ')' range_variable op_column_commalist
which has become just '(' joined_table ')'
which thus has (by definition) no table range (alias).

Case changed in mega-(merge-)commit:

commit c41efc6d
Author: Jens-Heiner Rechtien <hr@openoffice.org>
Date:   Wed Nov 19 17:43:08 2008 +0000

    CWS-TOOLING: integrate CWS dba301a_DEV300

which seems to have done the other necessary adaptations to this code
and elsewhere.

Change-Id: I96ddbefbf34d6c155435b78aa9e5037a760232ed