Add ITS#4644 fix for DN X.509 normalization crash

CHANGES

@@ -4,6 +4,7 @@ OpenLDAP 2.3.26 Release
 	Fixed libldap dnssrv bug with "not present" positive statement (ITS#4610)
 	Fixed libldap dangling pointer issue (ITS#4405)
 	Fixed slapd incorrect rebuilding of replica URI (ITS#4633)
+	Fixed slapd DN X.509 normalization crash (ITS#4644)
 	Fixed slapd-monitor operations order via callbacks (ITS#4631)
 	Fixed slapo-accesslog purge task during shutdown
 	Fixed slapo-ppolicy handling of default policy (ITS#4634)

servers/slapd/dn.c

@@ -1410,7 +1410,8 @@ dnX509normalize( void *x509_name, struct berval *out )
 	int rc = ldap_X509dn2bv( x509_name, out, LDAPDN_rewrite, 0 );
 
 	Debug( LDAP_DEBUG_TRACE,
-		"dnX509Normalize: <%s>\n", out->bv_val, 0, 0 );
+		"dnX509Normalize: <%s> (%d)\n",
+		BER_BVISNULL( out ) ? "(null)" : out->bv_val, rc, 0 );
 
 	return rc;
 }