Correct magic-folder use of StorageFarmBroker

When landing the "connected enough" changes on master,
we changed the API; this fixes up usage of it in magic-folder.

src/allmydata/client.py

@@ -121,7 +121,6 @@ class Client(node.Node, pollmixin.PollMixin):
                                    }
 
     def __init__(self, basedir="."):
-        #print "Client.__init__(%r)" % (basedir,)
         node.Node.__init__(self, basedir)
         # All tub.registerReference must happen *after* we upcall, since
         # that's what does tub.setLocation()
@@ -374,11 +373,6 @@ class Client(node.Node, pollmixin.PollMixin):
         self.storage_broker = sb
         sb.setServiceParent(self)
 
-        connection_threshold = min(self.encoding_params["k"],
-                                   self.encoding_params["happy"] + 1)
-        helper = storage_client.ConnectedEnough(sb, connection_threshold)
-        self.connected_enough_d = helper.when_connected_enough()
-
         # utilize the loaded static server specifications
         for key, server in self.connections_config['servers'].items():
             eventually(self.storage_broker.got_static_announcement,
@@ -498,7 +492,13 @@ class Client(node.Node, pollmixin.PollMixin):
             s.startService()
 
             # start processing the upload queue when we've connected to enough servers
-            self.connected_enough_d.addCallback(lambda ign: s.ready())
+            connection_threshold = min(self.encoding_params["k"],
+                                       self.encoding_params["happy"] + 1)
+            connected = storage_client.ConnectedEnough(
+                self.storage_broker,
+                connection_threshold,
+            )
+            connected.when_connected_enough().addCallback(lambda ign: s.ready())
 
     def _check_exit_trigger(self, exit_trigger_file):
         if os.path.exists(exit_trigger_file):

src/allmydata/test/check_magicfolder_smoke.py

@@ -127,7 +127,10 @@ node_id = 0
 for name in ['alice', 'bob']:
     data_dir = join(data_base, name)
     magic_dir = join(data_base, '%s-magic' % (name,))
-    mkdir(magic_dir)
+    try:
+        mkdir(magic_dir)
+    except OSError:
+        pass
     if not exists(data_dir):
         do_invites = True
         subprocess.check_call(

src/allmydata/test/no_network.py

@@ -175,6 +175,8 @@ class NoNetworkStorageBroker:
         return self.client._servers
     def get_nickname_for_serverid(self, serverid):
         return None
+    def on_servers_changed(self, cb):
+        pass
 
 class NoNetworkClient(Client):
 

src/allmydata/test/test_client.py

@@ -248,7 +248,7 @@ class Basic(testutil.ReallyEqualMixin, testutil.NonASCIIPathMixin, unittest.Test
         self.failUnlessReallyEqual(self._permute(sb, "one"), [])
 
     def test_permute_with_preferred(self):
-        sb = StorageFarmBroker(True, ['1','4'])
+        sb = StorageFarmBroker(True, preferred_peers=['1','4'])
         for k in ["%d" % i for i in range(5)]:
             ann = {"anonymous-storage-FURL": "pb://abcde@nowhere/fake",
                    "permutation-seed-base32": base32.b2a(k) }