- Patch #127753 by ChrisKennedy and GreenMother: regex error with session.cookie_domain settings.

sites/default/settings.php

@@ -140,7 +140,7 @@
  * We try to set the correct cookie domain.
  */
 if (isset($_SERVER['HTTP_HOST'])) {
-  $domain = '.'. preg_replace('`^www.`', '', $_SERVER['HTTP_HOST']);
+  $domain = '.'. preg_replace('`^www\.`', '', $_SERVER['HTTP_HOST']);
   // Per RFC 2109, cookie domains must contain at least one dot other than the
   // first. For hosts such as 'localhost', we don't set a cookie domain.
   if (count(explode('.', $domain)) > 2) {