Treat exact domain match cookies on public suffixes as host cookies.

net/cookies/cookie_util.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/cookies/cookie_util.h"
 
 #include <cstdio>
 #include <cstdlib>
 
 #include "base/logging.h"
@@ skipping 45 matching lines @@
   std::string cookie_domain(CanonicalizeHost(domain_string, &ignored));
   if (cookie_domain.empty())
     return false;
   if (cookie_domain[0] != '.')
     cookie_domain = "." + cookie_domain;
 
   // Ensure |url| and |cookie_domain| have the same domain+registry.
   const std::string url_scheme(url.scheme());
   const std::string url_domain_and_registry(
       GetEffectiveDomain(url_scheme, url_host));
-  if (url_domain_and_registry.empty())
-    return false;  // IP addresses/intranet hosts can't set domain cookies.
+  if (url_domain_and_registry.empty()) {
+    // We match IE/Firefox by treating an exact match between the domain
+    // attribute and the request host to be treated as a host cookie.
+    if (url_host == domain_string) {
+      *result = url_host;
+      DCHECK(DomainIsHostOnly(*result));
+      return true;
+    }
+
+    // Otherwise, IP addresses/intranet hosts/public suffixes can't set
+    // domain cookies.
+    return false;
+  }
   const std::string cookie_domain_and_registry(
       GetEffectiveDomain(url_scheme, cookie_domain));
   if (url_domain_and_registry != cookie_domain_and_registry)
     return false;  // Can't set a cookie on a different domain + registry.
 
   // Ensure |url_host| is |cookie_domain| or one of its subdomains.  Given that
   // we know the domain+registry are the same from the above checks, this is
   // basically a simple string suffix check.
   const bool is_suffix = (url_host.length() < cookie_domain.length()) ?
       (cookie_domain != ("." + url_host)) :
@@ skipping 184 matching lines @@
       buffer.append("; ");
     buffer.append(i->first.begin(), i->first.end());
     buffer.push_back('=');
     buffer.append(i->second.begin(), i->second.end());
   }
   return buffer;
 }
 
 }  // namespace cookie_util
 }  // namespace net