com.c (ffecom_arglist_expr_): Crash if non-supplied optional arg isn't passed as...

com.c (ffecom_arglist_expr_): Crash if non-supplied optional arg isn't passed as an address.

        * com.c (ffecom_arglist_expr_): Crash if non-supplied
        optional arg isn't passed as an address.
        Pass null pointer explicitly, instead of via ffecom routine.
        If incoming argstring is NULL, substitute pointer to "0".
        Recognize '0' as ending the usual arg stuff, just like '\0'.
        * com.c (ffecom_arglist_expr_): Pass null pointers for optional
        args which aren't supplied.
More patches from Craig.

From-SVN: r18183