Fix off-by-one bug in bitncmp(): When comparing a number of bits divisible by

8, bitncmp() may dereference a pointer one byte out of bounds.

Chris Mikkelson (bug #5101)

src/backend/utils/adt/network.c

 /*
  *	PostgreSQL type definitions for the INET and CIDR types.
  *
- *	$PostgreSQL: pgsql/src/backend/utils/adt/network.c,v 1.74 2009/06/11 14:49:03 momjian Exp $
+ *	$PostgreSQL: pgsql/src/backend/utils/adt/network.c,v 1.75 2009/10/08 04:46:21 heikki Exp $
  *
  *	Jon Postel RIP 16 Oct 1998
  */
@@ -972,7 +972,7 @@ bitncmp(void *l, void *r, int n)
 
 	b = n / 8;
 	x = memcmp(l, r, b);
-	if (x)
+	if (x || (n % 8) == 0)
 		return x;
 
 	lb = ((const u_char *) l)[b];