Merge pull request #432 from SpencerPark/fix-381

Configure the connection_file if not already done

Author: minrk

jupyter_client/kernelapp.py

@@ -30,10 +30,12 @@ class KernelApp(JupyterApp):
 
     def initialize(self, argv=None):
         super(KernelApp, self).initialize(argv)
+        
+        cf_basename = 'kernel-%s.json' % uuid.uuid4()
+        self.config.setdefault('KernelManager', {}).setdefault('connection_file', os.path.join(self.runtime_dir, cf_basename))
         self.km = KernelManager(kernel_name=self.kernel_name,
                                 config=self.config)
-        cf_basename = 'kernel-%s.json' % uuid.uuid4()
-        self.km.connection_file = os.path.join(self.runtime_dir, cf_basename)
+        
         self.loop = IOLoop.current()
         self.loop.add_callback(self._record_started)