convert: fix "stdlib import follows local import" problem in transport

Before this patch, import-checker reports error below for importing
subversion python binding libraries.

    stdlib import "svn.*" follows local import: mercurial

hgext/convert/transport.py

@@ -1,135 +1,135 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2007 Daniel Holth <[e-mail]>
 # This is a stripped-down version of the original bzr-svn transport.py,
 # Copyright (C) 2006 Jelmer Vernooij <[e-mail]>
 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
 
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, see <http://www.gnu.org/licenses/>.
 from __future__ import absolute_import
 
-from mercurial import (
-    util,
-)
-
 import svn.client
 import svn.core
 import svn.ra
 
 Pool = svn.core.Pool
 SubversionException = svn.core.SubversionException
 
+from mercurial import (
+    util,
+)
+
 # Some older versions of the Python bindings need to be
 # explicitly initialized. But what we want to do probably
 # won't work worth a darn against those libraries anyway!
 svn.ra.initialize()
 
 svn_config = svn.core.svn_config_get_config(None)
 
 
 def _create_auth_baton(pool):
     """Create a Subversion authentication baton. """
     import svn.client
     # Give the client context baton a suite of authentication
     # providers.h
     providers = [
         svn.client.get_simple_provider(pool),
         svn.client.get_username_provider(pool),
         svn.client.get_ssl_client_cert_file_provider(pool),
         svn.client.get_ssl_client_cert_pw_file_provider(pool),
         svn.client.get_ssl_server_trust_file_provider(pool),
         ]
     # Platform-dependent authentication methods
     getprovider = getattr(svn.core, 'svn_auth_get_platform_specific_provider',
                           None)
     if getprovider:
         # Available in svn >= 1.6
         for name in ('gnome_keyring', 'keychain', 'kwallet', 'windows'):
             for type in ('simple', 'ssl_client_cert_pw', 'ssl_server_trust'):
                 p = getprovider(name, type, pool)
                 if p:
                     providers.append(p)
     else:
         if util.safehasattr(svn.client, 'get_windows_simple_provider'):
             providers.append(svn.client.get_windows_simple_provider(pool))
 
     return svn.core.svn_auth_open(providers, pool)
 
 class NotBranchError(SubversionException):
     pass
 
 class SvnRaTransport(object):
     """
     Open an ra connection to a Subversion repository.
     """
     def __init__(self, url="", ra=None):
         self.pool = Pool()
         self.svn_url = url
         self.username = ''
         self.password = ''
 
         # Only Subversion 1.4 has reparent()
         if ra is None or not util.safehasattr(svn.ra, 'reparent'):
             self.client = svn.client.create_context(self.pool)
             ab = _create_auth_baton(self.pool)
             if False:
                 svn.core.svn_auth_set_parameter(
                     ab, svn.core.SVN_AUTH_PARAM_DEFAULT_USERNAME, self.username)
                 svn.core.svn_auth_set_parameter(
                     ab, svn.core.SVN_AUTH_PARAM_DEFAULT_PASSWORD, self.password)
             self.client.auth_baton = ab
             self.client.config = svn_config
             try:
                 self.ra = svn.client.open_ra_session(
                     self.svn_url,
                     self.client, self.pool)
             except SubversionException as xxx_todo_changeme:
                 (inst, num) = xxx_todo_changeme.args
                 if num in (svn.core.SVN_ERR_RA_ILLEGAL_URL,
                            svn.core.SVN_ERR_RA_LOCAL_REPOS_OPEN_FAILED,
                            svn.core.SVN_ERR_BAD_URL):
                     raise NotBranchError(url)
                 raise
         else:
             self.ra = ra
             svn.ra.reparent(self.ra, self.svn_url.encode('utf8'))
 
     class Reporter(object):
         def __init__(self, reporter_data):
             self._reporter, self._baton = reporter_data
 
         def set_path(self, path, revnum, start_empty, lock_token, pool=None):
             svn.ra.reporter2_invoke_set_path(self._reporter, self._baton,
                         path, revnum, start_empty, lock_token, pool)
 
         def delete_path(self, path, pool=None):
             svn.ra.reporter2_invoke_delete_path(self._reporter, self._baton,
                     path, pool)
 
         def link_path(self, path, url, revision, start_empty, lock_token,
                       pool=None):
             svn.ra.reporter2_invoke_link_path(self._reporter, self._baton,
                     path, url, revision, start_empty, lock_token,
                     pool)
 
         def finish_report(self, pool=None):
             svn.ra.reporter2_invoke_finish_report(self._reporter,
                     self._baton, pool)
 
         def abort_report(self, pool=None):
             svn.ra.reporter2_invoke_abort_report(self._reporter,
                     self._baton, pool)
 
     def do_update(self, revnum, path, *args, **kwargs):
         return self.Reporter(svn.ra.do_update(self.ra, revnum, path,
                                               *args, **kwargs))