diff -r 000000000000 -r 6474c204b198 tools/mercurial/hgsetup/config.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tools/mercurial/hgsetup/config.py	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,159 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this,
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import unicode_literals
+
+from configobj import ConfigObj
+import re
+import os
+
+
+HOST_FINGERPRINTS = {
+    'bitbucket.org': '45:ad:ae:1a:cf:0e:73:47:06:07:e0:88:f5:cc:10:e5:fa:1c:f7:99',
+    'bugzilla.mozilla.org': '47:13:a2:14:0c:46:45:53:12:0d:e5:36:16:a5:60:26:3e:da:3a:60',
+    'hg.mozilla.org': 'af:27:b9:34:47:4e:e5:98:01:f6:83:2b:51:c9:aa:d8:df:fb:1a:27',
+}
+
+
+class MercurialConfig(object):
+    """Interface for manipulating a Mercurial config file."""
+
+    def __init__(self, infiles=None):
+        """Create a new instance, optionally from an existing hgrc file."""
+
+        if infiles:
+            # If multiple files were specified, figure out which file we're using:
+            if len(infiles) > 1:
+                picky_infiles = filter(os.path.isfile, infiles)
+                if picky_infiles:
+                    picky_infiles = [(os.path.getsize(path), path) for path in picky_infiles]
+                    infiles = [max(picky_infiles)[1]]
+
+            infile = infiles[0]
+            self.config_path = infile
+        else:
+            infile = None
+
+        # write_empty_values is necessary to prevent built-in extensions (which
+        # have no value) from being dropped on write.
+        # list_values aren't needed by Mercurial and disabling them prevents
+        # quotes from being added.
+        self._c = ConfigObj(infile=infile, encoding='utf-8',
+            write_empty_values=True, list_values=False)
+
+    @property
+    def config(self):
+        return self._c
+
+    @property
+    def extensions(self):
+        """Returns the set of currently enabled extensions (by name)."""
+        return set(self._c.get('extensions', {}).keys())
+
+    def write(self, fh):
+        return self._c.write(fh)
+
+    def have_valid_username(self):
+        if 'ui' not in self._c:
+            return False
+
+        if 'username' not in self._c['ui']:
+            return False
+
+        # TODO perform actual validation here.
+
+        return True
+
+    def add_mozilla_host_fingerprints(self):
+        """Add host fingerprints so SSL connections don't warn."""
+        if 'hostfingerprints' not in self._c:
+            self._c['hostfingerprints'] = {}
+
+        for k, v in HOST_FINGERPRINTS.items():
+            self._c['hostfingerprints'][k] = v
+
+    def set_username(self, name, email):
+        """Set the username to use for commits.
+
+        The username consists of a name (typically <firstname> <lastname>) and
+        a well-formed e-mail address.
+        """
+        if 'ui' not in self._c:
+            self._c['ui'] = {}
+
+        username = '%s <%s>' % (name, email)
+
+        self._c['ui']['username'] = username.strip()
+
+    def activate_extension(self, name, path=None):
+        """Activate an extension.
+
+        An extension is defined by its name (in the config) and a filesystem
+        path). For built-in extensions, an empty path is specified.
+        """
+        if not path:
+            path = ''
+
+        if 'extensions' not in self._c:
+            self._c['extensions'] = {}
+
+        self._c['extensions'][name] = path
+
+    def have_recommended_diff_settings(self):
+        if 'diff' not in self._c:
+            return False
+
+        old = dict(self._c['diff'])
+        try:
+            self.ensure_recommended_diff_settings()
+        finally:
+            self._c['diff'].update(old)
+
+        return self._c['diff'] == old
+
+    def ensure_recommended_diff_settings(self):
+        if 'diff' not in self._c:
+            self._c['diff'] = {}
+
+        d = self._c['diff']
+        d['git'] = 1
+        d['showfunc'] = 1
+        d['unified'] = 8
+
+    def have_mqext_autocommit_mq(self):
+        if 'mqext' not in self._c:
+            return False
+        v = self._c['mqext'].get('mqcommit')
+        return v == 'auto' or v == 'yes'
+
+    def ensure_mqext_autocommit_mq(self):
+        if self.have_mqext_autocommit_mq():
+            return
+        if 'mqext' not in self._c:
+            self._c['mqext'] = {}
+        self._c['mqext']['mqcommit'] = 'auto'
+
+    def have_qnew_currentuser_default(self):
+        if 'defaults' not in self._c:
+            return False
+        d = self._c['defaults']
+        if 'qnew' not in d:
+            return False
+        argv = d['qnew'].split(' ')
+        for arg in argv:
+            if arg == '--currentuser' or re.match("-[^-]*U.*", arg):
+                return True
+        return False
+
+    def ensure_qnew_currentuser_default(self):
+        if self.have_qnew_currentuser_default():
+            return
+        if 'defaults' not in self._c:
+            self._c['defaults'] = {}
+
+        d = self._c['defaults']
+        if 'qnew' not in d:
+            d['qnew'] = '-U'
+        else:
+            d['qnew'] = '-U ' + d['qnew']