Fix weird with Client.behaviors.update.

This would manifest itself in pylibmc setting seemingly random (but
consistently so) values for the updated behaviors.

Not sure how or why this works when the previous code didn't.

pylibmc.py

@@ -57,9 +57,9 @@ class BehaviorDict(dict):
         super(BehaviorDict, self).__setitem__(name, value)
         self.client.set_behaviors({name: value})
 
-    def update(self, *args, **kwds):
-        super(BehaviorDict, self).update(*args, **kwds)
-        self.client.set_behaviors(self.copy())
+    def update(self, d):
+        super(BehaviorDict, self).update(d)
+        self.client.set_behaviors(d.copy())
 
 class Client(_pylibmc.client):
     def __init__(self, servers, binary=False):
@@ -115,9 +115,9 @@ class Client(_pylibmc.client):
         This also happens for `distribution`.
         """
         behaviors = behaviors.copy()
-        if behaviors.get("hash", None) in hashers:
+        if behaviors.get("hash") is not None:
             behaviors["hash"] = hashers[behaviors["hash"]]
-        if behaviors.get("distribution") in distributions:
+        if behaviors.get("distribution") is not None:
             behaviors["distribution"] = distributions[behaviors["distribution"]]
         return super(Client, self).set_behaviors(behaviors)
 

tests.py

@@ -1,9 +1,11 @@
 """Tests. They want YOU!!
 
+
 Basic functionality.
 >>> _pylibmc.__version__ == pylibmc.__version__
 True
 >>> c = _pylibmc.client([test_server])
+>>> c.get("hello")
 >>> c.set("test_key", 123)
 True
 >>> c.get("test_key")
@@ -177,6 +179,14 @@ Empty server lists are bad for your health.
 Traceback (most recent call last):
   ...
 MemcachedError: empty server list
+
+Python-wrapped behaviors dict
+>>> pc = pylibmc.Client(["%s:%d" % test_server[1:]])
+>>> (pc.behaviors["hash"], pc.behaviors["distribution"])
+('default', 'modula')
+>>> pc.behaviors.update({"hash": "fnv1a_32", "distribution": "consistent"})
+>>> (pc.behaviors["hash"], pc.behaviors["distribution"])
+('fnv1a_32', 'consistent')
 """
 
 # Used to test pickling.