1 files changed, 55 insertions, 51 deletions

diff --git a/src/mailman/config/config.py b/src/mailman/config/config.py
index 7181e23e9..779fa27e5 100644
--- a/src/mailman/config/config.py
+++ b/src/mailman/config/config.py
@@ -17,9 +17,6 @@
 
 """Configuration file loading and management."""
 
-from __future__ import absolute_import, print_function, unicode_literals
-
-__metaclass__ = type
 __all__ = [
     'Configuration',
     'external_configuration',
@@ -29,27 +26,28 @@ __all__ = [
 
 import os
 import sys
+import mailman.templates
 
-from ConfigParser import SafeConfigParser
 from flufl.lock import Lock
 from lazr.config import ConfigSchema, as_boolean
-from pkg_resources import resource_stream, resource_string
-from string import Template
-from zope.component import getUtility
-from zope.event import notify
-from zope.interface import implementer
-
-import mailman.templates
-
 from mailman import version
 from mailman.interfaces.configuration import (
     ConfigurationUpdatedEvent, IConfiguration, MissingConfigurationFileError)
 from mailman.interfaces.languages import ILanguageManager
 from mailman.utilities.filesystem import makedirs
 from mailman.utilities.modules import call_name, expand_path
+from pkg_resources import resource_filename, resource_string as resource_bytes
+from six.moves.configparser import ConfigParser, RawConfigParser
+from string import Template
+from unittest.mock import patch
+from zope.component import getUtility
+from zope.event import notify
+from zope.interface import implementer
 
 
 SPACE = ' '
+SPACERS = '\n'
+
 
 MAILMAN_CFG_TEMPLATE = """\
 # AUTOMATICALLY GENERATED BY MAILMAN ON {}
@@ -66,6 +64,11 @@ MAILMAN_CFG_TEMPLATE = """\
 # enabled: yes
 # recipient: your.address@your.domain"""
 
+class _NonStrictRawConfigParser(RawConfigParser):
+    def __init__(self, *args, **kws):
+        kws['strict'] = False
+        super().__init__(*args, **kws)
+
 
 
 @implementer(IConfiguration)
@@ -102,30 +105,29 @@ class Configuration:
 
     def load(self, filename=None):
         """Load the configuration from the schema and config files."""
-        schema_file = config_file = None
-        try:
-            schema_file = resource_stream('mailman.config', 'schema.cfg')
-            schema = ConfigSchema('schema.cfg', schema_file)
-            # If a configuration file was given, load it now too.  First, load
-            # the absolute minimum default configuration, then if a
-            # configuration filename was given by the user, push it.
-            config_file = resource_stream('mailman.config', 'mailman.cfg')
-            self._config = schema.loadFile(config_file, 'mailman.cfg')
-            if filename is not None:
-                self.filename = filename
-                with open(filename) as user_config:
-                    self._config.push(filename, user_config.read())
-        finally:
-            if schema_file:
-                schema_file.close()
-            if config_file:
-                config_file.close()
-        self._post_process()
+        schema_file = resource_filename('mailman.config', 'schema.cfg')
+        schema = ConfigSchema(schema_file)
+        # If a configuration file was given, load it now too.  First, load
+        # the absolute minimum default configuration, then if a
+        # configuration filename was given by the user, push it.
+        config_file = resource_filename('mailman.config', 'mailman.cfg')
+        self._config = schema.load(config_file)
+        if filename is None:
+            self._post_process()
+        else:
+            self.filename = filename
+            with open(filename, 'r', encoding='utf-8') as user_config:
+                self.push(filename, user_config.read())
 
     def push(self, config_name, config_string):
         """Push a new configuration onto the stack."""
         self._clear()
-        self._config.push(config_name, config_string)
+        # In Python 3, the RawConfigParser() must be created with
+        # strict=False, otherwise we'll get a DuplicateSectionError.
+        # See https://bugs.launchpad.net/lazr.config/+bug/1397779
+        with patch('lazr.config._config.RawConfigParser',
+                   _NonStrictRawConfigParser):
+            self._config.push(config_name, config_string)
         self._post_process()
 
     def pop(self, config_name):
@@ -164,6 +166,7 @@ class Configuration:
         # path is relative.
         var_dir = os.environ.get('MAILMAN_VAR_DIR', category.var_dir)
         substitutions = dict(
+            cwd                     = os.getcwd(),
             argv                    = bin_dir,
             # Directories.
             bin_dir                 = category.bin_dir,
@@ -185,26 +188,32 @@ class Configuration:
             lock_file               = category.lock_file,
             pid_file                = category.pid_file,
             )
+        # Add the path to the .cfg file, if one was given on the command line.
+        if self.filename is not None:
+            substitutions['cfg_file'] = self.filename
         # Now, perform substitutions recursively until there are no more
         # variables with $-vars in them, or until substitutions are not
         # helping any more.
         last_dollar_count = 0
         while True:
+            expandables = []
             # Mutate the dictionary during iteration.
-            dollar_count = 0
-            for key in substitutions.keys():
+            for key in substitutions:
                 raw_value = substitutions[key]
                 value = Template(raw_value).safe_substitute(substitutions)
                 if '$' in value:
                     # Still more work to do.
-                    dollar_count += 1
+                    expandables.append((key, value))
                 substitutions[key] = value
-            if dollar_count == 0:
+            if len(expandables) == 0:
                 break
-            if dollar_count == last_dollar_count:
-                print('Path expansion infloop detected', file=sys.stderr)
+            if len(expandables) == last_dollar_count:
+                print('Path expansion infloop detected:\n',
+                      SPACERS.join('\t{}: {}'.format(key, value)
+                                   for key, value in sorted(expandables)),
+                      file=sys.stderr)
                 sys.exit(1)
-            last_dollar_count = dollar_count
+            last_dollar_count = len(expandables)
         # Ensure that all paths are normalized and made absolute.  Handle the
         # few special cases first.  Most of these are due to backward
         # compatibility.
@@ -269,7 +278,7 @@ class Configuration:
 
 
 
-def load_external(path, encoding=None):
+def load_external(path):
     """Load the configuration file named by path.
 
     :param path: A string naming the location of the external configuration
@@ -278,21 +287,16 @@ def load_external(path, encoding=None):
         value must name a ``.cfg`` file located within Python's import path,
         however the trailing ``.cfg`` suffix is implied (don't provide it
         here).
-    :param encoding: The encoding to apply to the data read from path.  If
-        None, then bytes will be returned.
-    :return: A unicode string or bytes, depending on ``encoding``.
+    :return: The contents of the configuration file.
+    :rtype: str
     """
     # Is the context coming from a file system or Python path?
     if path.startswith('python:'):
         resource_path = path[7:]
         package, dot, resource = resource_path.rpartition('.')
-        config_string = resource_string(package, resource + '.cfg')
-    else:
-        with open(path, 'rb') as fp:
-            config_string = fp.read()
-    if encoding is None:
-        return config_string
-    return config_string.decode(encoding)
+        return resource_bytes(package, resource + '.cfg').decode('utf-8')
+    with open(path, 'r', encoding='utf-8') as fp:
+        return fp.read()
 
 
 def external_configuration(path):
@@ -308,7 +312,7 @@ def external_configuration(path):
     """
     # Is the context coming from a file system or Python path?
     cfg_path = expand_path(path)
-    parser = SafeConfigParser()
+    parser = ConfigParser()
     files = parser.read(cfg_path)
     if files != [cfg_path]:
         raise MissingConfigurationFileError(path)