Fixed #27181 -- Allowed contrib.sites to match domains with trailing ".".

django/contrib/sites/models.py

@@ -46,8 +46,6 @@ class SiteManager(models.Manager):
         except Site.DoesNotExist:
             # Fallback to looking up site after stripping port from the host.
             domain, port = split_domain_port(host)
-            if not port:
-                raise
             if domain not in SITE_CACHE:
                 SITE_CACHE[domain] = self.get(domain__iexact=domain)
             return SITE_CACHE[domain]

django/http/request.py

@@ -554,9 +554,10 @@ def split_domain_port(host):
         # It's an IPv6 address without a port.
         return host, ''
     bits = host.rsplit(':', 1)
-    if len(bits) == 2:
-        return tuple(bits)
-    return bits[0], ''
+    domain, port = bits if len(bits) == 2 else (bits[0], '')
+    # Remove a trailing dot (if present) from the domain.
+    domain = domain[:-1] if domain.endswith('.') else domain
+    return domain, port
 
 
 def validate_host(host, allowed_hosts):
@@ -574,8 +575,6 @@ def validate_host(host, allowed_hosts):
 
     Return ``True`` for a valid host, ``False`` otherwise.
     """
-    host = host[:-1] if host.endswith('.') else host
-
     for pattern in allowed_hosts:
         if pattern == '*' or is_same_domain(host, pattern):
             return True