Compatibility fix for Tornado 3.x

IPython/html/terminal/handlers.py

@@ -1,28 +1,43 b''
 """Tornado handlers for the terminal emulator."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
+import tornado
 from tornado import web
 import terminado
 from ..base.handlers import IPythonHandler
 
 class TerminalHandler(IPythonHandler):
     """Render the terminal interface."""
     @web.authenticated
     def get(self, term_name):
         self.write(self.render_template('terminal.html',
                    ws_path="terminals/websocket/%s" % term_name))
 
 class NewTerminalHandler(IPythonHandler):
     """Redirect to a new terminal."""
     @web.authenticated
     def get(self):
         name, _ = self.application.terminal_manager.new_named_terminal()
         self.redirect(name, permanent=False)
 
 class TermSocket(terminado.TermSocket, IPythonHandler):
     def get(self, *args, **kwargs):
         if not self.get_current_user():
             raise web.HTTPError(403)
-        return super(TermSocket, self).get(*args, **kwargs)
+
+        # FIXME: only do super get on tornado ≥ 4
+        # tornado 3 has no get, will raise 405
+        if tornado.version_info >= (4,):
+            return super(TermSocket, self).get(*args, **kwargs)
+
+    def open(self, *args, **kwargs):
+        if tornado.version_info < (4,):
+            try:
+                self.get(*self.open_args, **self.open_kwargs)
+            except web.HTTPError:
+                self.close()
+                raise
+
+        super(TermSocket, self).open(*args, **kwargs)