*** pgsql/src/backend/utils/adt/varlena.c	Sun Apr  7 11:44:54 2002
--- pgsql.orig/src/backend/utils/adt/varlena.c	Mon Apr  8 22:32:16 2002
***************
*** 413,419 ****
  	if (eml > 1)
  	{
  		sm = 0;
! 		sn = (m + n) * eml + 3; /* +3 to avoid mb characters overhanging slice end */
  	}
  #endif 
  
--- 373,382 ----
  	if (eml > 1)
  	{
  		sm = 0;
! 		if (n > -1)
! 			sn = (m + n) * eml + 3; /* +3 to avoid mb characters overhanging slice end */
! 		else
! 			sn = n;		/* n < 0 is special-cased by heap_tuple_untoast_attr_slice */
  	}
  #endif 
  
***************
*** 427,433 ****
  	PG_RETURN_NULL();   /* notreached: suppress compiler warning */
  #endif
  #ifdef MULTIBYTE
! 	len = pg_mbstrlen_with_len (VARDATA (string), sn - 3);
  
  	if (m > len)
  	{
--- 390,399 ----
  	PG_RETURN_NULL();   /* notreached: suppress compiler warning */
  #endif
  #ifdef MULTIBYTE
! 	if (n > -1)
! 		len = pg_mbstrlen_with_len (VARDATA (string), sn - 3);
! 	else	/* n < 0 is special-cased; need full string length */
! 		len = pg_mbstrlen (VARDATA (string));
  
  	if (m > len)
  	{