improving hostname extraction

scrapy/http/cookies.py

@@ -22,11 +22,7 @@ class CookieJar(object):
 
         # the cookiejar implementation iterates through all domains
         # instead we restrict to potential matches on the domain
-        req_host = urlparse_cached(request).netloc
-
-        # Strip port numbers from netloc, if present
-        if ':' in req_host:
-            req_host = req_host.split(':')[0]
+        req_host = urlparse_cached(request).hostname
 
         if not IPV4_RE.search(req_host):
             hosts = potential_domain_matches(req_host)