Index: Lib/BaseHTTPServer.py
===================================================================
--- Lib/BaseHTTPServer.py	(révision 80469)
+++ Lib/BaseHTTPServer.py	(copie de travail)
@@ -484,16 +484,12 @@
                  'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
 
     def address_string(self):
-        """Return the client address formatted for logging.
+        """Return the client address formatted for logging."""
+        if not hasattr(self, 'client_address_string'):
+            host, port = self.client_address[:2]
+            self.client_address_string = socket.getfqdn(host)
+        return self.client_address_string
 
-        This version looks up the full hostname using gethostbyaddr(),
-        and tries to find a name that contains at least one dot.
-
-        """
-
-        host, port = self.client_address[:2]
-        return socket.getfqdn(host)
-
     # Essentially static class variables
 
     # The version of the HTTP protocol we support.