(Missing patch from the PHP 4 tree that got lost in the shuffle)

See: http://cvs.php.net/viewcvs.cgi/php-src/ext/session/session.c?r1=1.336.2.39&r2=1.336.2.40
- fix logic. if the client already sent us the cookie, we don't
  need to send it again.  if the id has been changed, we need to
  update the client side.

ext/session/session.c

@@ -1088,8 +1088,9 @@ static void php_session_reset_id(TSRMLS_D)
 {
 	int module_number = PS(module_number);
 	
-	if (PS(use_cookies)) {
+	if (PS(use_cookies) && PS(send_cookie)) {
 		php_session_send_cookie(TSRMLS_C);
+		PS(send_cookie) = 0;
 	}
 
 	/* if the SID constant exists, destroy it. */
@@ -1485,6 +1486,7 @@ PHP_FUNCTION(session_regenerate_id)
 	
 		PS(id) = PS(mod)->s_create_sid(&PS(mod_data), NULL TSRMLS_CC);
 
+		PS(send_cookie) = 1;
 		php_session_reset_id(TSRMLS_C);
 		
 		RETURN_TRUE;