diff -Naur -x CVS -x LocalSettings.php -x AdminSettings.php wikipedia.cvs20031121/includes/SpecialUserlogin.php wikipedia.cvs20031121.with-cookie-check/includes/SpecialUserlogin.php
--- wikipedia.cvs20031121/includes/SpecialUserlogin.php	2003-11-15 13:26:37.000000000 +0000
+++ wikipedia.cvs20031121.with-cookie-check/includes/SpecialUserlogin.php	2003-11-21 18:40:13.000000000 +0000
@@ -77,6 +77,10 @@
 	global $wgUser, $wgOut, $wpPassword, $wpRetype, $wpName, $wpRemember;
 	global $wpEmail, $wgDeferredUpdateList;
 
+        if (!cookieCheck()) {
+                return;
+        }
+
 	if (!$wgUser->isAllowedToCreateAccount()) {
 		userNotPrivilegedMessage();
 		return;
@@ -122,6 +126,10 @@
 	global $wgUser, $wpName, $wpPassword, $wpRemember;
 	global $returnto;
 
+        if (!cookieCheck()) {
+                return;
+        }
+
 	if ( "" == $wpName ) {
 		mainLoginForm( wfMsg( "noname" ) );
 		return;
@@ -160,7 +168,7 @@
 {
 	global $wgUser, $wpName, $wgDeferredUpdateList, $wgOutputEncoding;
 	global $wgCookiePath, $wgCookieDomain, $wgDBname;
-	
+
 	if ( "" == $wpName ) {
 		mainLoginForm( wfMsg( "noname" ) );
 		return;
@@ -357,4 +365,25 @@
 
 }
 
+/* private */ function cookieCheck() {
+
+        global $HTTP_COOKIE_VARS, $wgOut, $returnto;
+
+        # XXX: kind of crude check to see if cookies are enabled, but it works OK
+
+        if ( "" == $HTTP_COOKIE_VARS[session_name()])
+        {
+                # Don't go back to login page; they won't get time to
+                # enable cookies and send us one, so they'll get this msg again. Instead, 
+                # let them enable cookies on the error page, then go back to login page.
+                # XXX: wipes returnto, unfortunately.
+
+                $returnto = "Special:Userlogin";                
+		$wgOut->errorpage( "nocookies", "nocookiestext" );
+                return false;
+        }
+
+        return true;
+}
+
 ?>
diff -Naur -x CVS -x LocalSettings.php -x AdminSettings.php wikipedia.cvs20031121/languages/Language.php wikipedia.cvs20031121.with-cookie-check/languages/Language.php
--- wikipedia.cvs20031121/languages/Language.php	2003-11-20 13:40:30.000000000 +0000
+++ wikipedia.cvs20031121.with-cookie-check/languages/Language.php	2003-11-21 18:08:05.000000000 +0000
@@ -546,6 +546,8 @@
 email address to them, and it also helps you if you forget your   
 password.",
 "loginerror"	=> "Login error",
+"nocookies"	=> "Cookies disabled",
+"nocookiestext"	=> "Wikipedia uses cookies to log in users. You have cookies disabled. Please enable them and try again.",
 "noname"		=> "You have not specified a valid user name.",
 "loginsuccesstitle" => "Login successful",
 "loginsuccess"	=> "You are now logged in to Wikipedia as \"$1\".",