httpconnection: remove a mutable default argument

Mutable default arguments are know to the state of California to cause bugs.

mercurial/httpconnection.py

@@ -1,284 +1,286 b''
 # httpconnection.py - urllib2 handler for new http support
 #
 # Copyright 2005, 2006, 2007, 2008 Matt Mackall <[e-mail]>
 # Copyright 2006, 2007 Alexis S. L. Carvalho <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 # Copyright 2011 Google, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 import logging
 import socket
 import urllib
 import urllib2
 import os
 
 from mercurial import httpclient
 from mercurial import sslutil
 from mercurial import util
 from mercurial.i18n import _
 
 # moved here from url.py to avoid a cycle
 class httpsendfile(object):
     """This is a wrapper around the objects returned by python's "open".
 
     Its purpose is to send file-like objects via HTTP.
     It do however not define a __len__ attribute because the length
     might be more than Py_ssize_t can handle.
     """
 
     def __init__(self, ui, *args, **kwargs):
         # We can't just "self._data = open(*args, **kwargs)" here because there
         # is an "open" function defined in this module that shadows the global
         # one
         self.ui = ui
         self._data = open(*args, **kwargs)
         self.seek = self._data.seek
         self.close = self._data.close
         self.write = self._data.write
         self.length = os.fstat(self._data.fileno()).st_size
         self._pos = 0
         self._total = self.length // 1024 * 2
 
     def read(self, *args, **kwargs):
         try:
             ret = self._data.read(*args, **kwargs)
         except EOFError:
             self.ui.progress(_('sending'), None)
         self._pos += len(ret)
         # We pass double the max for total because we currently have
         # to send the bundle twice in the case of a server that
         # requires authentication. Since we can't know until we try
         # once whether authentication will be required, just lie to
         # the user and maybe the push succeeds suddenly at 50%.
         self.ui.progress(_('sending'), self._pos // 1024,
                          unit=_('kb'), total=self._total)
         return ret
 
 # moved here from url.py to avoid a cycle
 def readauthforuri(ui, uri, user):
     # Read configuration
     config = dict()
     for key, val in ui.configitems('auth'):
         if '.' not in key:
             ui.warn(_("ignoring invalid [auth] key '%s'\n") % key)
             continue
         group, setting = key.rsplit('.', 1)
         gdict = config.setdefault(group, dict())
         if setting in ('username', 'cert', 'key'):
             val = util.expandpath(val)
         gdict[setting] = val
 
     # Find the best match
     scheme, hostpath = uri.split('://', 1)
     bestuser = None
     bestlen = 0
     bestauth = None
     for group, auth in config.iteritems():
         if user and user != auth.get('username', user):
             # If a username was set in the URI, the entry username
             # must either match it or be unset
             continue
         prefix = auth.get('prefix')
         if not prefix:
             continue
         p = prefix.split('://', 1)
         if len(p) > 1:
             schemes, prefix = [p[0]], p[1]
         else:
             schemes = (auth.get('schemes') or 'https').split()
         if (prefix == '*' or hostpath.startswith(prefix)) and \
             (len(prefix) > bestlen or (len(prefix) == bestlen and \
                 not bestuser and 'username' in auth)) \
              and scheme in schemes:
             bestlen = len(prefix)
             bestauth = group, auth
             bestuser = auth.get('username')
             if user and not bestuser:
                 auth['username'] = user
     return bestauth
 
 # Mercurial (at least until we can remove the old codepath) requires
 # that the http response object be sufficiently file-like, so we
 # provide a close() method here.
 class HTTPResponse(httpclient.HTTPResponse):
     def close(self):
         pass
 
 class HTTPConnection(httpclient.HTTPConnection):
     response_class = HTTPResponse
-    def request(self, method, uri, body=None, headers={}):
+    def request(self, method, uri, body=None, headers=None):
+        if headers is None:
+            headers = {}
         if isinstance(body, httpsendfile):
             body.seek(0)
         httpclient.HTTPConnection.request(self, method, uri, body=body,
                                           headers=headers)
 
 
 _configuredlogging = False
 LOGFMT = '%(levelname)s:%(name)s:%(lineno)d:%(message)s'
 # Subclass BOTH of these because otherwise urllib2 "helpfully"
 # reinserts them since it notices we don't include any subclasses of
 # them.
 class http2handler(urllib2.HTTPHandler, urllib2.HTTPSHandler):
     def __init__(self, ui, pwmgr):
         global _configuredlogging
         urllib2.AbstractHTTPHandler.__init__(self)
         self.ui = ui
         self.pwmgr = pwmgr
         self._connections = {}
         # developer config: ui.http2debuglevel
         loglevel = ui.config('ui', 'http2debuglevel', default=None)
         if loglevel and not _configuredlogging:
             _configuredlogging = True
             logger = logging.getLogger('mercurial.httpclient')
             logger.setLevel(getattr(logging, loglevel.upper()))
             handler = logging.StreamHandler()
             handler.setFormatter(logging.Formatter(LOGFMT))
             logger.addHandler(handler)
 
     def close_all(self):
         """Close and remove all connection objects being kept for reuse."""
         for openconns in self._connections.values():
             for conn in openconns:
                 conn.close()
         self._connections = {}
 
     # shamelessly borrowed from urllib2.AbstractHTTPHandler
     def do_open(self, http_class, req, use_ssl):
         """Return an addinfourl object for the request, using http_class.
 
         http_class must implement the HTTPConnection API from httplib.
         The addinfourl return value is a file-like object.  It also
         has methods and attributes including:
             - info(): return a mimetools.Message object for the headers
             - geturl(): return the original request URL
             - code: HTTP status code
         """
         # If using a proxy, the host returned by get_host() is
         # actually the proxy. On Python 2.6.1, the real destination
         # hostname is encoded in the URI in the urllib2 request
         # object. On Python 2.6.5, it's stored in the _tunnel_host
         # attribute which has no accessor.
         tunhost = getattr(req, '_tunnel_host', None)
         host = req.get_host()
         if tunhost:
             proxyhost = host
             host = tunhost
         elif req.has_proxy():
             proxyhost = req.get_host()
             host = req.get_selector().split('://', 1)[1].split('/', 1)[0]
         else:
             proxyhost = None
 
         if proxyhost:
             if ':' in proxyhost:
                 # Note: this means we'll explode if we try and use an
                 # IPv6 http proxy. This isn't a regression, so we
                 # won't worry about it for now.
                 proxyhost, proxyport = proxyhost.rsplit(':', 1)
             else:
                 proxyport = 3128 # squid default
             proxy = (proxyhost, proxyport)
         else:
             proxy = None
 
         if not host:
             raise urllib2.URLError('no host given')
 
         connkey = use_ssl, host, proxy
         allconns = self._connections.get(connkey, [])
         conns = [c for c in allconns if not c.busy()]
         if conns:
             h = conns[0]
         else:
             if allconns:
                 self.ui.debug('all connections for %s busy, making a new '
                               'one\n' % host)
             timeout = None
             if req.timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
                 timeout = req.timeout
             h = http_class(host, timeout=timeout, proxy_hostport=proxy)
             self._connections.setdefault(connkey, []).append(h)
 
         headers = dict(req.headers)
         headers.update(req.unredirected_hdrs)
         headers = dict(
             (name.title(), val) for name, val in headers.items())
         try:
             path = req.get_selector()
             if '://' in path:
                 path = path.split('://', 1)[1].split('/', 1)[1]
             if path[0] != '/':
                 path = '/' + path
             h.request(req.get_method(), path, req.data, headers)
             r = h.getresponse()
         except socket.error as err: # XXX what error?
             raise urllib2.URLError(err)
 
         # Pick apart the HTTPResponse object to get the addinfourl
         # object initialized properly.
         r.recv = r.read
 
         resp = urllib.addinfourl(r, r.headers, req.get_full_url())
         resp.code = r.status
         resp.msg = r.reason
         return resp
 
     # httplib always uses the given host/port as the socket connect
     # target, and then allows full URIs in the request path, which it
     # then observes and treats as a signal to do proxying instead.
     def http_open(self, req):
         if req.get_full_url().startswith('https'):
             return self.https_open(req)
         def makehttpcon(*args, **kwargs):
             k2 = dict(kwargs)
             k2['use_ssl'] = False
             return HTTPConnection(*args, **k2)
         return self.do_open(makehttpcon, req, False)
 
     def https_open(self, req):
         # req.get_full_url() does not contain credentials and we may
         # need them to match the certificates.
         url = req.get_full_url()
         user, password = self.pwmgr.find_stored_password(url)
         res = readauthforuri(self.ui, url, user)
         if res:
             group, auth = res
             self.auth = auth
             self.ui.debug("using auth.%s.* for authentication\n" % group)
         else:
             self.auth = None
         return self.do_open(self._makesslconnection, req, True)
 
     def _makesslconnection(self, host, port=443, *args, **kwargs):
         keyfile = None
         certfile = None
 
         if args: # key_file
             keyfile = args.pop(0)
         if args: # cert_file
             certfile = args.pop(0)
 
         # if the user has specified different key/cert files in
         # hgrc, we prefer these
         if self.auth and 'key' in self.auth and 'cert' in self.auth:
             keyfile = self.auth['key']
             certfile = self.auth['cert']
 
         # let host port take precedence
         if ':' in host and '[' not in host or ']:' in host:
             host, port = host.rsplit(':', 1)
             port = int(port)
             if '[' in host:
                 host = host[1:-1]
 
         kwargs['keyfile'] = keyfile
         kwargs['certfile'] = certfile
 
         kwargs.update(sslutil.sslkwargs(self.ui, host))
 
         con = HTTPConnection(host, port, use_ssl=True,
                              ssl_wrap_socket=sslutil.wrapsocket,
                              ssl_validator=sslutil.validator(self.ui, host),
                              **kwargs)
         return con