prompt: You will be provided with a partial code base and an issue statement explaining a problem to resolve.
  <issue>
  Exception when logout with auto_login=True
  **How to reproduce the issue**
  Press logout button
  
  **What you expected to happen**
  Shows logout.html
  
  **What actually happens**
  Exception:
  ```
      Traceback (most recent call last):
        File "/usr/local/lib/python3.5/dist-packages/tornado/web.py", line 1509, in _execute
          result = method(*self.path_args, **self.path_kwargs)
        File "/usr/local/lib/python3.5/dist-packages/jupyterhub/handlers/login.py", line 23, in get
          self.render('logout.html')
        File "/usr/local/lib/python3.5/dist-packages/tornado/web.py", line 724, in render
          html = self.render_string(template_name, **kwargs)
        File "/usr/local/lib/python3.5/dist-packages/tornado/web.py", line 857, in render_string
          if template_path not in RequestHandler._template_loaders:
      TypeError: unhashable type: 'list'
  ```
  
  **Share what version of JupyterHub you are using**
  Jupyterhub 0.8 with auto_login=True
  
  Running `jupyter troubleshoot` from the command line, if possible, and posting
  its output would also be helpful.
  
  ```
  $PATH:
  	/usr/local/bin
  	/usr/local/sbin
  	/usr/local/bin
  	/usr/sbin
  	/usr/bin
  	/sbin
  	/bin
  
  sys.path:
  	/usr/local/bin
  	/srv/jupyterhub
  	/usr/lib/python35.zip
  	/usr/lib/python3.5
  	/usr/lib/python3.5/plat-x86_64-linux-gnu
  	/usr/lib/python3.5/lib-dynload
  	/usr/local/lib/python3.5/dist-packages
  	/usr/lib/python3/dist-packages
  
  sys.executable:
  	/usr/bin/python3
  
  sys.version:
  	3.5.3 (default, Jan 19 2017, 14:11:04)
  	[GCC 6.3.0 20170118]
  
  platform.platform():
  	Linux-4.4.52+-x86_64-with-Ubuntu-17.04-zesty
  
  which -a jupyter:
  	/usr/local/bin/jupyter
  	/usr/local/bin/jupyter
  ```
  
  
  </issue>
  <code>
  [start of jupyterhub/handlers/login.py]
  1 """HTTP Handlers for the hub server"""
  2 
  3 # Copyright (c) Jupyter Development Team.
  4 # Distributed under the terms of the Modified BSD License.
  5 
  6 from tornado.escape import url_escape
  7 from tornado import gen
  8 from tornado.httputil import url_concat
  9 from tornado import web
  10 
  11 from .base import BaseHandler
  12 
  13 
  14 class LogoutHandler(BaseHandler):
  15     """Log a user out by clearing their login cookie."""
  16     def get(self):
  17         user = self.get_current_user()
  18         if user:
  19             self.log.info("User logged out: %s", user.name)
  20             self.clear_login_cookie()
  21             self.statsd.incr('logout')
  22         if self.authenticator.auto_login:
  23             self.render('logout.html')
  24         else:
  25             self.redirect(self.settings['login_url'], permanent=False)
  26 
  27 
  28 class LoginHandler(BaseHandler):
  29     """Render the login page."""
  30 
  31     def _render(self, login_error=None, username=None):
  32         return self.render_template('login.html',
  33                 next=url_escape(self.get_argument('next', default='')),
  34                 username=username,
  35                 login_error=login_error,
  36                 custom_html=self.authenticator.custom_html,
  37                 login_url=self.settings['login_url'],
  38                 authenticator_login_url=url_concat(
  39                     self.authenticator.login_url(self.hub.base_url),
  40                     {'next': self.get_argument('next', '')},
  41                 ),
  42         )
  43 
  44     @gen.coroutine
  45     def get(self):
  46         self.statsd.incr('login.request')
  47         user = self.get_current_user()
  48         if user:
  49             # set new login cookie
  50             # because single-user cookie may have been cleared or incorrect
  51             self.set_login_cookie(self.get_current_user())
  52             self.redirect(self.get_next_url(user), permanent=False)
  53         else:
  54             if self.authenticator.auto_login:
  55                 auto_login_url = self.authenticator.login_url(self.hub.base_url)
  56                 if auto_login_url == self.settings['login_url']:
  57                     # auto_login without a custom login handler
  58                     # means that auth info is already in the request
  59                     # (e.g. REMOTE_USER header)
  60                     user = yield self.login_user()
  61                     if user is None:
  62                         # auto_login failed, just 403
  63                         raise web.HTTPError(403)
  64                     else:
  65                         self.redirect(self.get_next_url(user))
  66                 else:
  67                     if self.get_argument('next', default=False):
  68                         auto_login_url = url_concat(auto_login_url, {'next': self.get_next_url()})
  69                     self.redirect(auto_login_url)
  70                 return
  71             username = self.get_argument('username', default='')
  72             self.finish(self._render(username=username))
  73 
  74     @gen.coroutine
  75     def post(self):
  76         # parse the arguments dict
  77         data = {}
  78         for arg in self.request.arguments:
  79             data[arg] = self.get_argument(arg, strip=False)
  80 
  81         auth_timer = self.statsd.timer('login.authenticate').start()
  82         user = yield self.login_user(data)
  83         auth_timer.stop(send=False)
  84 
  85         if user:
  86             already_running = False
  87             if user.spawner.ready:
  88                 status = yield user.spawner.poll()
  89                 already_running = (status is None)
  90             if not already_running and not user.spawner.options_form \
  91                     and not user.spawner.pending:
  92                 # logging in triggers spawn
  93                 yield self.spawn_single_user(user)
  94             self.redirect(self.get_next_url())
  95         else:
  96             html = self._render(
  97                 login_error='Invalid username or password',
  98                 username=data['username'],
  99             )
  100             self.finish(html)
  101 
  102 
  103 # /login renders the login page or the "Login with..." link,
  104 # so it should always be registered.
  105 # /logout clears cookies.
  106 default_handlers = [
  107     (r"/login", LoginHandler),
  108     (r"/logout", LogoutHandler),
  109 ]
  110
  [end of jupyterhub/handlers/login.py]
  </code>
  
  I need you to solve this issue by generating a single patch file that I can apply directly to this repository using git apply. Please respond with a single patch file in the following format.
  <patch>
  diff --git a/file.py b/file.py
  --- a/file.py
  +++ b/file.py
  @@ -1,27 +1,35 @@
   def euclidean(a, b):
  -    while b:
  -        a, b = b, a % b
  -    return a
  +    if b == 0:
  +        return a
  +    return euclidean(b, a % b)
   
   
   def bresenham(x0, y0, x1, y1):
       points = []
       dx = abs(x1 - x0)
       dy = abs(y1 - y0)
  -    sx = 1 if x0 < x1 else -1
  -    sy = 1 if y0 < y1 else -1
  -    err = dx - dy
  +    x, y = x0, y0
  +    sx = -1 if x0 > x1 else 1
  +    sy = -1 if y0 > y1 else 1
   
  -    while True:
  -        points.append((x0, y0))
  -        if x0 == x1 and y0 == y1:
  -            break
  -        e2 = 2 * err
  -        if e2 > -dy:
  -            err -= dy
  -            x0 += sx
  -        if e2 < dx:
  -            err += dx
  -            y0 += sy
  +    if dx > dy:
  +        err = dx / 2.0
  +        while x != x1:
  +            points.append((x, y))
  +            err -= dy
  +            if err < 0:
  +                y += sy
  +                err += dx
  +            x += sx
  +    else:
  +        err = dy / 2.0
  +        while y != y1:
  +            points.append((x, y))
  +            err -= dx
  +            if err < 0:
  +                x += sx
  +                err += dy
  +            y += sy
  +
  +    points.append((x, y))
       return points
  
  </patch>
golden_diff: diff --git a/jupyterhub/handlers/login.py b/jupyterhub/handlers/login.py
  --- a/jupyterhub/handlers/login.py
  +++ b/jupyterhub/handlers/login.py
  @@ -20,7 +20,7 @@
               self.clear_login_cookie()
               self.statsd.incr('logout')
           if self.authenticator.auto_login:
  -            self.render('logout.html')
  +            self.render_template('logout.html')
           else:
               self.redirect(self.settings['login_url'], permanent=False)
  
verification_info: {"golden_diff": "diff --git a/jupyterhub/handlers/login.py b/jupyterhub/handlers/login.py\n--- a/jupyterhub/handlers/login.py\n+++ b/jupyterhub/handlers/login.py\n@@ -20,7 +20,7 @@\n             self.clear_login_cookie()\n             self.statsd.incr('logout')\n         if self.authenticator.auto_login:\n-            self.render('logout.html')\n+            self.render_template('logout.html')\n         else:\n             self.redirect(self.settings['login_url'], permanent=False)\n", "issue": "Exception when logout with auto_login=True\n**How to reproduce the issue**\r\nPress logout button\r\n\r\n**What you expected to happen**\r\nShows logout.html\r\n\r\n**What actually happens**\r\nException:\r\n```\r\n    Traceback (most recent call last):\r\n      File \"/usr/local/lib/python3.5/dist-packages/tornado/web.py\", line 1509, in _execute\r\n        result = method(*self.path_args, **self.path_kwargs)\r\n      File \"/usr/local/lib/python3.5/dist-packages/jupyterhub/handlers/login.py\", line 23, in get\r\n        self.render('logout.html')\r\n      File \"/usr/local/lib/python3.5/dist-packages/tornado/web.py\", line 724, in render\r\n        html = self.render_string(template_name, **kwargs)\r\n      File \"/usr/local/lib/python3.5/dist-packages/tornado/web.py\", line 857, in render_string\r\n        if template_path not in RequestHandler._template_loaders:\r\n    TypeError: unhashable type: 'list'\r\n```\r\n\r\n**Share what version of JupyterHub you are using**\r\nJupyterhub 0.8 with auto_login=True\r\n\r\nRunning `jupyter troubleshoot` from the command line, if possible, and posting\r\nits output would also be helpful.\r\n\r\n```\r\n$PATH:\r\n\t/usr/local/bin\r\n\t/usr/local/sbin\r\n\t/usr/local/bin\r\n\t/usr/sbin\r\n\t/usr/bin\r\n\t/sbin\r\n\t/bin\r\n\r\nsys.path:\r\n\t/usr/local/bin\r\n\t/srv/jupyterhub\r\n\t/usr/lib/python35.zip\r\n\t/usr/lib/python3.5\r\n\t/usr/lib/python3.5/plat-x86_64-linux-gnu\r\n\t/usr/lib/python3.5/lib-dynload\r\n\t/usr/local/lib/python3.5/dist-packages\r\n\t/usr/lib/python3/dist-packages\r\n\r\nsys.executable:\r\n\t/usr/bin/python3\r\n\r\nsys.version:\r\n\t3.5.3 (default, Jan 19 2017, 14:11:04)\r\n\t[GCC 6.3.0 20170118]\r\n\r\nplatform.platform():\r\n\tLinux-4.4.52+-x86_64-with-Ubuntu-17.04-zesty\r\n\r\nwhich -a jupyter:\r\n\t/usr/local/bin/jupyter\r\n\t/usr/local/bin/jupyter\r\n```\r\n\n", "before_files": [{"content": "\"\"\"HTTP Handlers for the hub server\"\"\"\n\n# Copyright (c) Jupyter Development Team.\n# Distributed under the terms of the Modified BSD License.\n\nfrom tornado.escape import url_escape\nfrom tornado import gen\nfrom tornado.httputil import url_concat\nfrom tornado import web\n\nfrom .base import BaseHandler\n\n\nclass LogoutHandler(BaseHandler):\n    \"\"\"Log a user out by clearing their login cookie.\"\"\"\n    def get(self):\n        user = self.get_current_user()\n        if user:\n            self.log.info(\"User logged out: %s\", user.name)\n            self.clear_login_cookie()\n            self.statsd.incr('logout')\n        if self.authenticator.auto_login:\n            self.render('logout.html')\n        else:\n            self.redirect(self.settings['login_url'], permanent=False)\n\n\nclass LoginHandler(BaseHandler):\n    \"\"\"Render the login page.\"\"\"\n\n    def _render(self, login_error=None, username=None):\n        return self.render_template('login.html',\n                next=url_escape(self.get_argument('next', default='')),\n                username=username,\n                login_error=login_error,\n                custom_html=self.authenticator.custom_html,\n                login_url=self.settings['login_url'],\n                authenticator_login_url=url_concat(\n                    self.authenticator.login_url(self.hub.base_url),\n                    {'next': self.get_argument('next', '')},\n                ),\n        )\n\n    @gen.coroutine\n    def get(self):\n        self.statsd.incr('login.request')\n        user = self.get_current_user()\n        if user:\n            # set new login cookie\n            # because single-user cookie may have been cleared or incorrect\n            self.set_login_cookie(self.get_current_user())\n            self.redirect(self.get_next_url(user), permanent=False)\n        else:\n            if self.authenticator.auto_login:\n                auto_login_url = self.authenticator.login_url(self.hub.base_url)\n                if auto_login_url == self.settings['login_url']:\n                    # auto_login without a custom login handler\n                    # means that auth info is already in the request\n                    # (e.g. REMOTE_USER header)\n                    user = yield self.login_user()\n                    if user is None:\n                        # auto_login failed, just 403\n                        raise web.HTTPError(403)\n                    else:\n                        self.redirect(self.get_next_url(user))\n                else:\n                    if self.get_argument('next', default=False):\n                        auto_login_url = url_concat(auto_login_url, {'next': self.get_next_url()})\n                    self.redirect(auto_login_url)\n                return\n            username = self.get_argument('username', default='')\n            self.finish(self._render(username=username))\n\n    @gen.coroutine\n    def post(self):\n        # parse the arguments dict\n        data = {}\n        for arg in self.request.arguments:\n            data[arg] = self.get_argument(arg, strip=False)\n\n        auth_timer = self.statsd.timer('login.authenticate').start()\n        user = yield self.login_user(data)\n        auth_timer.stop(send=False)\n\n        if user:\n            already_running = False\n            if user.spawner.ready:\n                status = yield user.spawner.poll()\n                already_running = (status is None)\n            if not already_running and not user.spawner.options_form \\\n                    and not user.spawner.pending:\n                # logging in triggers spawn\n                yield self.spawn_single_user(user)\n            self.redirect(self.get_next_url())\n        else:\n            html = self._render(\n                login_error='Invalid username or password',\n                username=data['username'],\n            )\n            self.finish(html)\n\n\n# /login renders the login page or the \"Login with...\" link,\n# so it should always be registered.\n# /logout clears cookies.\ndefault_handlers = [\n    (r\"/login\", LoginHandler),\n    (r\"/logout\", LogoutHandler),\n]\n", "path": "jupyterhub/handlers/login.py"}]}