Index: modules/quercus/src/com/caucho/quercus/lib/session/SessionModule.java
===================================================================
--- modules/quercus/src/com/caucho/quercus/lib/session/SessionModule.java	(revision 2500)
+++ modules/quercus/src/com/caucho/quercus/lib/session/SessionModule.java	(working copy)
@@ -535,7 +535,8 @@
         cookie.setMaxAge(maxAge.toInt());
 
       Value domain = env.getIni("session.cookie_domain");
-      cookie.setDomain(domain.toString());
+      if (domain.length() != 0)
+        cookie.setDomain(domain.toString());
 
       Value secure = env.getIni("session.cookie_secure");
       cookie.setSecure(secure.toBoolean());