diff -r 43d55088415a -r 67964cda8701 mercurial/keepalive.py
--- a/mercurial/keepalive.py	Sat May 12 16:00:53 2012 +0200
+++ b/mercurial/keepalive.py	Sat May 12 16:00:57 2012 +0200
@@ -136,7 +136,7 @@
     def add(self, host, connection, ready):
         self._lock.acquire()
         try:
-            if not host in self._hostmap:
+            if host not in self._hostmap:
                 self._hostmap[host] = []
             self._hostmap[host].append(connection)
             self._connmap[connection] = host