Merge lp:~jelmer/brz/probe-hg into lp:brz

[Jelmer Vernooij]

Add a Mercurial prober that mentions that mercurial repositories are unsupported.

Add a Mercurial prober that mentions that mercurial repositories are unsupported.

[Jelmer Vernooij (jelmer)]

review: Approve

[The Breezy Bot (the-breezy-bot)]

Merging failed
https://ci.breezy-vcs.org/job/brz/job/brz-land/584/

[The Breezy Bot (the-breezy-bot)]

Merging failed
https://ci.breezy-vcs.org/job/brz/job/brz-land/586/

[The Breezy Bot (the-breezy-bot)]

Running landing tests failed
https://ci.breezy-vcs.org/job/brz/job/brz-land/589/

=== modified file 'breezy/annotate.py'
--- breezy/annotate.py	2019-06-16 01:03:51 +0000
+++ breezy/annotate.py	2020-01-11 17:50:43 +0000
@@ -36,12 +36,12 @@
 import patiencediff
 
 from breezy import (
-    errors,
     tsort,
     )
 """)
 from . import (
     config,
+    errors,
     osutils,
     )
 from .repository import _strip_NULL_ghosts
 
=== modified file 'breezy/bedding.py'
--- breezy/bedding.py	2019-06-16 19:53:27 +0000
+++ breezy/bedding.py	2020-01-11 17:50:43 +0000
@@ -25,12 +25,14 @@
 from .lazy_import import lazy_import
 lazy_import(globals(), """
 from breezy import (
-    errors,
     osutils,
     trace,
     win32utils,
     )
 """)
+from . import (
+    errors,
+    )
 from .sixish import (
     PY3,
     )
 
=== modified file 'breezy/builtins.py'
--- breezy/builtins.py	2019-10-13 18:52:37 +0000
+++ breezy/builtins.py	2020-01-11 17:50:43 +0000
@@ -25,6 +25,10 @@
 import breezy.bzr
 import breezy.git
 
+from . import (
+    errors,
+    )
+
 from . import lazy_import
 lazy_import.lazy_import(globals(), """
 import time
@@ -38,7 +42,6 @@
     directory_service,
     delta,
     config as _mod_config,
-    errors,
     globbing,
     gpg,
     hooks,
 
=== modified file 'breezy/bzr/bundle/commands.py'
--- breezy/bzr/bundle/commands.py	2019-07-25 22:19:30 +0000
+++ breezy/bzr/bundle/commands.py	2020-01-11 17:50:43 +0000
@@ -23,11 +23,14 @@
 
 from __future__ import absolute_import
 
+from ... import (
+    errors,
+    )
+
 from ...lazy_import import lazy_import
 lazy_import(globals(), """
 from breezy import (
     branch,
-    errors,
     merge_directive,
     revision as _mod_revision,
     urlutils,
 
=== modified file 'breezy/bzr/knitpack_repo.py'
--- breezy/bzr/knitpack_repo.py	2019-01-09 00:04:02 +0000
+++ breezy/bzr/knitpack_repo.py	2020-01-11 17:50:43 +0000
@@ -18,6 +18,10 @@
 
 from __future__ import absolute_import
 
+from .. import (
+    errors,
+    )
+
 from ..lazy_import import lazy_import
 lazy_import(globals(), """
 import time
@@ -25,7 +29,6 @@
 from breezy import (
     controldir,
     debug,
-    errors,
     osutils,
     revision as _mod_revision,
     trace,
 
=== modified file 'breezy/bzr/knitrepo.py'
--- breezy/bzr/knitrepo.py	2018-11-30 12:39:04 +0000
+++ breezy/bzr/knitrepo.py	2020-01-11 17:50:43 +0000
@@ -22,7 +22,6 @@
 
 from breezy import (
     controldir,
-    errors,
     lockable_files,
     lockdir,
     osutils,
@@ -38,6 +37,9 @@
     xml7,
     )
 """)
+from .. import (
+    errors,
+    )
 from ..repository import (
     InterRepository,
     IsInWriteGroupError,
 
=== modified file 'breezy/bzr/smart/ping.py'
--- breezy/bzr/smart/ping.py	2018-08-08 02:10:06 +0000
+++ breezy/bzr/smart/ping.py	2020-01-11 17:50:43 +0000
@@ -23,11 +23,12 @@
 from ...sixish import viewitems
 
 lazy_import(globals(), """
-from breezy import errors
 from breezy.bzr.smart.client import _SmartClient
 from breezy.transport import get_transport
 """)
 
+from breezy import errors
+
 
 class cmd_ping(Command):
     """Pings a Bazaar smart server.
 
=== modified file 'breezy/bzr/versionedfile.py'
--- breezy/bzr/versionedfile.py	2019-06-16 15:20:09 +0000
+++ breezy/bzr/versionedfile.py	2020-01-11 17:50:43 +0000
@@ -29,7 +29,6 @@
 from breezy import (
     annotate,
     bencode,
-    errors,
     graph as _mod_graph,
     osutils,
     multiparent,
@@ -43,6 +42,9 @@
     knit,
     )
 """)
+from .. import (
+    errors,
+    )
 from ..registry import Registry
 from ..sixish import (
     BytesIO,
 
=== modified file 'breezy/bzr/workingtree_4.py'
--- breezy/bzr/workingtree_4.py	2020-01-11 14:56:33 +0000
+++ breezy/bzr/workingtree_4.py	2020-01-11 17:50:43 +0000
@@ -38,7 +38,6 @@
     cleanup,
     controldir,
     debug,
-    errors,
     filters as _mod_filters,
     osutils,
     revision as _mod_revision,
@@ -53,6 +52,9 @@
     )
 """)
 
+from .. import (
+    errors,
+    )
 from .inventory import Inventory, ROOT_ID, entry_factory
 from ..lock import LogicalLockResult
 from ..lockable_files import LockableFiles
 
=== modified file 'breezy/cmd_version_info.py'
--- breezy/cmd_version_info.py	2018-11-12 01:41:38 +0000
+++ breezy/cmd_version_info.py	2020-01-11 17:50:43 +0000
@@ -23,13 +23,15 @@
 lazy_import(globals(), """
 from breezy import (
     branch,
-    errors,
     version_info_formats,
     workingtree,
     )
 from breezy.i18n import gettext
 """)
 
+from . import (
+    errors,
+    )
 from .commands import Command
 from .option import Option, RegistryOption
 from .sixish import text_type
 
=== modified file 'breezy/conflicts.py'
--- breezy/conflicts.py	2019-06-22 11:16:17 +0000
+++ breezy/conflicts.py	2020-01-11 17:50:43 +0000
@@ -27,7 +27,6 @@
 import errno
 
 from breezy import (
-    errors,
     osutils,
     rio,
     trace,
@@ -38,6 +37,7 @@
 """)
 from . import (
     cache_utf8,
+    errors,
     commands,
     option,
     registry,
 
=== modified file 'breezy/diff.py'
--- breezy/diff.py	2019-12-23 01:39:21 +0000
+++ breezy/diff.py	2020-01-11 17:50:43 +0000
@@ -31,7 +31,6 @@
 from breezy import (
     cleanup,
     controldir,
-    errors,
     osutils,
     textfile,
     timestamp,
@@ -42,6 +41,9 @@
 from breezy.i18n import gettext
 """)
 
+from . import (
+    errors,
+    )
 from .registry import (
     Registry,
     )
 
=== modified file 'breezy/errors.py'
--- breezy/errors.py	2019-09-01 16:44:05 +0000
+++ breezy/errors.py	2020-01-11 17:50:43 +0000
@@ -2027,41 +2027,6 @@
         self.revision_id = revision_id
 
 
-class IllegalUseOfScopeReplacer(InternalBzrError):
-
-    _fmt = ("ScopeReplacer object %(name)r was used incorrectly:"
-            " %(msg)s%(extra)s")
-
-    def __init__(self, name, msg, extra=None):
-        BzrError.__init__(self)
-        self.name = name
-        self.msg = msg
-        if extra:
-            self.extra = ': ' + str(extra)
-        else:
-            self.extra = ''
-
-
-class InvalidImportLine(InternalBzrError):
-
-    _fmt = "Not a valid import statement: %(msg)\n%(text)s"
-
-    def __init__(self, text, msg):
-        BzrError.__init__(self)
-        self.text = text
-        self.msg = msg
-
-
-class ImportNameCollision(InternalBzrError):
-
-    _fmt = ("Tried to import an object to the same name as"
-            " an existing object. %(name)s")
-
-    def __init__(self, name):
-        BzrError.__init__(self)
-        self.name = name
-
-
 class NotAMergeDirective(BzrError):
     """File starting with %(firstline)r is not a merge directive"""
 
 
=== modified file 'breezy/filters/__init__.py'
--- breezy/filters/__init__.py	2018-11-11 04:08:32 +0000
+++ breezy/filters/__init__.py	2020-01-11 17:50:43 +0000
@@ -48,12 +48,15 @@
 lazy_import(globals(), """
 from breezy import (
     config,
-    errors,
     osutils,
     registry,
     )
 """)
 
+from .. import (
+    errors,
+    )
+
 
 class ContentFilter(object):
 
 
=== modified file 'breezy/foreign.py'
--- breezy/foreign.py	2018-11-18 19:48:57 +0000
+++ breezy/foreign.py	2020-01-11 17:50:43 +0000
@@ -24,13 +24,10 @@
     )
 from .repository import Repository
 from .revision import Revision
-from .lazy_import import lazy_import
-lazy_import(globals(), """
-from breezy import (
+from . import (
     errors,
     registry,
     )
-""")
 
 
 class VcsMapping(object):
 
=== modified file 'breezy/ignores.py'
--- breezy/ignores.py	2019-11-19 18:10:28 +0000
+++ breezy/ignores.py	2020-01-11 17:50:43 +0000
@@ -27,11 +27,13 @@
 lazy_import(globals(), """
 from breezy import (
     atomicfile,
-    bedding,
     globbing,
     trace,
     )
 """)
+from . import (
+    bedding,
+    )
 
 # ~/.config/breezy/ignore will be filled out using
 # this ignore list, if it does not exist
 
=== modified file 'breezy/lazy_import.py'
--- breezy/lazy_import.py	2018-11-12 01:41:38 +0000
+++ breezy/lazy_import.py	2020-01-11 17:50:43 +0000
@@ -43,6 +43,43 @@
 
 from __future__ import absolute_import
 
+from .errors import BzrError, InternalBzrError
+
+
+class ImportNameCollision(InternalBzrError):
+
+    _fmt = ("Tried to import an object to the same name as"
+            " an existing object. %(name)s")
+
+    def __init__(self, name):
+        BzrError.__init__(self)
+        self.name = name
+
+
+class IllegalUseOfScopeReplacer(InternalBzrError):
+
+    _fmt = ("ScopeReplacer object %(name)r was used incorrectly:"
+            " %(msg)s%(extra)s")
+
+    def __init__(self, name, msg, extra=None):
+        BzrError.__init__(self)
+        self.name = name
+        self.msg = msg
+        if extra:
+            self.extra = ': ' + str(extra)
+        else:
+            self.extra = ''
+
+
+class InvalidImportLine(InternalBzrError):
+
+    _fmt = "Not a valid import statement: %(msg)\n%(text)s"
+
+    def __init__(self, text, msg):
+        BzrError.__init__(self)
+        self.text = text
+        self.msg = msg
+
 
 class ScopeReplacer(object):
     """A lazy object that will replace itself in the appropriate scope.
@@ -84,8 +121,9 @@
             scope = object.__getattribute__(self, '_scope')
             obj = factory(self, scope, name)
             if obj is self:
-                raise errors.IllegalUseOfScopeReplacer(name, msg="Object tried"
-                                                       " to replace itself, check it's not using its own scope.")
+                raise IllegalUseOfScopeReplacer(
+                    name, msg="Object tried"
+                    " to replace itself, check it's not using its own scope.")
 
             # Check if another thread has jumped in while obj was generated.
             real_obj = object.__getattribute__(self, '_real_obj')
@@ -99,7 +137,7 @@
 
         # Raise if proxying is disabled as obj has already been generated.
         if not ScopeReplacer._should_proxy:
-            raise errors.IllegalUseOfScopeReplacer(
+            raise IllegalUseOfScopeReplacer(
                 name, msg="Object already replaced, did you assign it"
                           " to another variable?")
         return real_obj
@@ -260,8 +298,8 @@
             elif line.startswith('from '):
                 self._convert_from_str(line)
             else:
-                raise errors.InvalidImportLine(line,
-                                               "doesn't start with 'import ' or 'from '")
+                raise InvalidImportLine(
+                    line, "doesn't start with 'import ' or 'from '")
 
     def _convert_import_str(self, import_str):
         """This converts a import string into an import map.
@@ -286,7 +324,7 @@
                 name = as_hunks[1].strip()
                 module_path = as_hunks[0].strip().split('.')
                 if name in self.imports:
-                    raise errors.ImportNameCollision(name)
+                    raise ImportNameCollision(name)
                 if not module_path[0]:
                     raise ImportError(path)
                 # No children available in 'import foo as bar'
@@ -345,7 +383,7 @@
             else:
                 name = module = path
             if name in self.imports:
-                raise errors.ImportNameCollision(name)
+                raise ImportNameCollision(name)
             self.imports[name] = (from_module_path, module, {})
 
     def _canonicalize_import_text(self, text):
@@ -377,7 +415,7 @@
                 else:
                     out.append(line.replace('(', '').replace(')', ''))
         if cur is not None:
-            raise errors.InvalidImportLine(cur, 'Unmatched parenthesis')
+            raise InvalidImportLine(cur, 'Unmatched parenthesis')
         return out
 
 
@@ -408,12 +446,3 @@
     # This is just a helper around ImportProcessor.lazy_import
     proc = ImportProcessor(lazy_import_class=lazy_import_class)
     return proc.lazy_import(scope, text)
-
-
-# The only module that this module depends on is 'breezy.errors'. But it
-# can actually be imported lazily, since we only need it if there is a
-# problem.
-
-lazy_import(globals(), """
-from breezy import errors
-""")
 
=== modified file 'breezy/lockable_files.py'
--- breezy/lockable_files.py	2018-11-11 04:08:32 +0000
+++ breezy/lockable_files.py	2020-01-11 17:50:43 +0000
@@ -20,13 +20,15 @@
 lazy_import(globals(), """
 from breezy import (
     counted_lock,
-    errors,
     lock,
     transactions,
     urlutils,
     )
 """)
 
+from . import (
+    errors,
+    )
 from .decorators import (
     only_raises,
     )
 
=== modified file 'breezy/merge_directive.py'
--- breezy/merge_directive.py	2019-07-27 22:47:49 +0000
+++ breezy/merge_directive.py	2020-01-11 17:50:43 +0000
@@ -26,7 +26,6 @@
     cleanup,
     diff,
     email_message,
-    errors,
     gpg,
     hooks,
     registry,
@@ -42,6 +41,9 @@
     serializer as bundle_serializer,
     )
 """)
+from . import (
+    errors,
+    )
 from .sixish import (
     BytesIO,
     )
 
=== modified file 'breezy/mergeable.py'
--- breezy/mergeable.py	2019-06-30 10:50:40 +0000
+++ breezy/mergeable.py	2020-01-11 17:50:43 +0000
@@ -19,7 +19,6 @@
 from .lazy_import import lazy_import
 lazy_import(globals(), """
 from breezy import (
-    errors,
     transport as _mod_transport,
     urlutils,
     )
@@ -28,6 +27,9 @@
 from breezy.i18n import gettext
 """)
 
+from . import (
+    errors,
+    )
 from .sixish import (
     BytesIO,
     )
 
=== modified file 'breezy/multiparent.py'
--- breezy/multiparent.py	2019-03-02 21:46:18 +0000
+++ breezy/multiparent.py	2020-01-11 17:50:43 +0000
@@ -28,10 +28,12 @@
 
 from breezy import (
     bencode,
-    errors,
     ui,
     )
 """)
+from . import (
+    errors,
+    )
 from .i18n import gettext
 from .sixish import (
     BytesIO,
 
=== modified file 'breezy/plugin.py'
--- breezy/plugin.py	2019-10-14 00:07:00 +0000
+++ breezy/plugin.py	2020-01-11 17:50:43 +0000
@@ -51,12 +51,15 @@
 from breezy import (
     bedding,
     debug,
-    errors,
     help_topics,
     trace,
     )
 """)
 
+from . import (
+    errors,
+    )
+
 
 _MODULE_PREFIX = "breezy.plugins."
 
 
=== added directory 'breezy/plugins/hg'
=== added file 'breezy/plugins/hg/__init__.py'
--- breezy/plugins/hg/__init__.py	1970-01-01 00:00:00 +0000
+++ breezy/plugins/hg/__init__.py	2020-01-11 17:50:43 +0000
@@ -0,0 +1,177 @@
+# Copyright (C) 2019 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; version 3 of the License or
+# (at your option) a 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+"""Mercurial foreign branch support.
+
+Currently only tells the user that Mercurial is not supported.
+"""
+
+from __future__ import absolute_import
+
+from ... import (
+    controldir,
+    errors,
+    )
+
+from ... import version_info  # noqa: F401
+
+
+class MercurialUnsupportedError(errors.UnsupportedFormatError):
+
+    _fmt = ('Mercurial branches are not yet supported. '
+            'To convert Mercurial branches to Bazaar branches or vice versa, '
+            'use the fastimport format. ')
+
+
+class LocalHgDirFormat(controldir.ControlDirFormat):
+    """Mercurial directory format."""
+
+    def get_converter(self):
+        raise NotImplementedError(self.get_converter)
+
+    def get_format_description(self):
+        return "Local Mercurial control directory"
+
+    def initialize_on_transport(self, transport):
+        raise errors.UninitializableFormat(self)
+
+    def is_supported(self):
+        return False
+
+    def supports_transport(self, transport):
+        return False
+
+    def check_support_status(self, allow_unsupported, recommend_upgrade=True,
+                             basedir=None):
+        raise MercurialUnsupportedError()
+
+    def open(self, transport):
+        # Raise NotBranchError if there is nothing there
+        LocalHgProber().probe_transport(transport)
+        raise NotImplementedError(self.open)
+
+
+class LocalHgProber(controldir.Prober):
+
+    @classmethod
+    def priority(klass, transport):
+        return 100
+
+    @staticmethod
+    def _has_hg_dumb_repository(transport):
+        try:
+            return transport.has_any([".hg/requires", ".hg/00changelog.i"])
+        except (errors.NoSuchFile, errors.PermissionDenied,
+                errors.InvalidHttpResponse):
+            return False
+
+    @classmethod
+    def probe_transport(klass, transport):
+        """Our format is present if the transport has a '.hg/' subdir."""
+        if klass._has_hg_dumb_repository(transport):
+            return HgDirFormat()
+        raise errors.NotBranchError(path=transport.base)
+
+    @classmethod
+    def known_formats(cls):
+        return [LocalHgDirFormat()]
+
+
+class SmartHgDirFormat(controldir.ControlDirFormat):
+    """Mercurial directory format."""
+
+    def get_converter(self):
+        raise NotImplementedError(self.get_converter)
+
+    def get_format_description(self):
+        return "Smart Mercurial control directory"
+
+    def initialize_on_transport(self, transport):
+        raise errors.UninitializableFormat(self)
+
+    def is_supported(self):
+        return False
+
+    def supports_transport(self, transport):
+        return False
+
+    def check_support_status(self, allow_unsupported, recommend_upgrade=True,
+                             basedir=None):
+        raise MercurialUnsupportedError()
+
+    def open(self, transport):
+        # Raise NotBranchError if there is nothing there
+        SmartHgProber().probe_transport(transport)
+        raise NotImplementedError(self.open)
+
+
+class SmartHgProber(controldir.Prober):
+
+    # Perhaps retrieve list from mercurial.hg.schemes ?
+    _supported_schemes = ["http", "https"]
+
+    @classmethod
+    def priority(klass, transport):
+        return 90
+
+    @staticmethod
+    def _has_hg_http_smart_server(transport, external_url):
+        """Check if there is a Mercurial smart server at the remote location.
+
+        :param transport: Transport to check
+        :param externa_url: External URL for transport
+        :return: Boolean indicating whether transport is backed onto hg
+        """
+        from breezy.urlutils import urlparse
+        parsed_url = urlparse.urlparse(external_url)
+        parsed_url = parsed_url._replace(
+            query='cmd=capabilities', path=parsed_url.path.rstrip('/') + '/hg')
+        url = urlparse.urlunparse(parsed_url)
+        resp = transport.request(
+            'GET', url, headers={'Accept': 'application/mercurial-0.1'})
+        if resp.status == 404:
+            return False
+        ct = resp.getheader("Content-Type")
+        if ct is None:
+            return False
+        return ct.startswith("application/mercurial")
+
+    @classmethod
+    def probe_transport(klass, transport):
+        try:
+            external_url = transport.external_url()
+        except errors.InProcessTransport:
+            raise errors.NotBranchError(path=transport.base)
+        scheme = external_url.split(":")[0]
+        if scheme not in klass._supported_schemes:
+            raise errors.NotBranchError(path=transport.base)
+        from breezy import urlutils
+        external_url = urlutils.split_segment_parameters(external_url)[0]
+        # Explicitly check for .hg directories here, so we avoid
+        # loading foreign branches through Mercurial.
+        if (external_url.startswith("http:") or
+                external_url.startswith("https:")):
+            if klass._has_hg_http_smart_server(transport, external_url):
+                return SmartHgDirFormat()
+        raise errors.NotBranchError(path=transport.base)
+
+    @classmethod
+    def known_formats(cls):
+        return [SmartHgDirFormat()]
+
+
+controldir.ControlDirFormat.register_prober(LocalHgProber)
+controldir.ControlDirFormat.register_prober(SmartHgProber)
 
=== modified file 'breezy/plugins/netrc_credential_store/__init__.py'
--- breezy/plugins/netrc_credential_store/__init__.py	2018-11-11 04:08:32 +0000
+++ breezy/plugins/netrc_credential_store/__init__.py	2020-01-11 17:50:43 +0000
@@ -23,16 +23,13 @@
 
 from ... import (
     config,
+    errors,
     lazy_import,
     )
 
 lazy_import.lazy_import(globals(), """
 import errno
 import netrc
-
-from breezy import (
-    errors,
-    )
 """)
 
 
 
=== modified file 'breezy/plugins/upload/cmds.py'
--- breezy/plugins/upload/cmds.py	2019-09-21 23:05:12 +0000
+++ breezy/plugins/upload/cmds.py	2020-01-11 17:50:43 +0000
@@ -21,6 +21,7 @@
 from ... import (
     commands,
     config,
+    errors,
     lazy_import,
     option,
     osutils,
@@ -30,7 +31,6 @@
 
 from breezy import (
     controldir,
-    errors,
     globbing,
     ignores,
     revision,
 
=== modified file 'breezy/tag.py'
--- breezy/tag.py	2019-06-22 16:20:00 +0000
+++ breezy/tag.py	2020-01-11 17:50:43 +0000
@@ -40,11 +40,14 @@
 from breezy import (
     bencode,
     cleanup,
-    errors,
     trace,
     )
 """)
 
+from . import (
+    errors,
+    )
+
 
 def _reconcile_tags(source_dict, dest_dict, overwrite):
     """Do a two-way merge of two tag dictionaries.
 
=== modified file 'breezy/tests/test_lazy_import.py'
--- breezy/tests/test_lazy_import.py	2018-11-11 04:08:32 +0000
+++ breezy/tests/test_lazy_import.py	2020-01-11 17:50:43 +0000
@@ -354,7 +354,7 @@
 
         # However, the next access on test_obj3 should raise an error
         # because only now are we able to detect the problem.
-        self.assertRaises(errors.IllegalUseOfScopeReplacer,
+        self.assertRaises(lazy_import.IllegalUseOfScopeReplacer,
                           getattr, test_obj3, 'foo')
 
         self.assertEqual([('__getattribute__', 'foo'),
@@ -448,7 +448,7 @@
 
         self.assertEqual(InstrumentedReplacer,
                          object.__getattribute__(test_obj7, '__class__'))
-        e = self.assertRaises(errors.IllegalUseOfScopeReplacer, test_obj7)
+        e = self.assertRaises(lazy_import.IllegalUseOfScopeReplacer, test_obj7)
         self.assertIn("replace itself", e.msg)
         self.assertEqual([('__call__', (), {}),
                           'factory'], actions)
@@ -917,7 +917,7 @@
 
     def test_missing_trailing(self):
         proc = lazy_import.ImportProcessor()
-        self.assertRaises(errors.InvalidImportLine,
+        self.assertRaises(lazy_import.InvalidImportLine,
                           proc._canonicalize_import_text,
                           "from foo import (\n  bar\n")
 
@@ -1016,13 +1016,13 @@
 
     def test_incorrect_line(self):
         proc = lazy_import.ImportProcessor()
-        self.assertRaises(errors.InvalidImportLine,
+        self.assertRaises(lazy_import.InvalidImportLine,
                           proc._build_map, 'foo bar baz')
-        self.assertRaises(errors.InvalidImportLine,
+        self.assertRaises(lazy_import.InvalidImportLine,
                           proc._build_map, 'improt foo')
-        self.assertRaises(errors.InvalidImportLine,
+        self.assertRaises(lazy_import.InvalidImportLine,
                           proc._build_map, 'importfoo')
-        self.assertRaises(errors.InvalidImportLine,
+        self.assertRaises(lazy_import.InvalidImportLine,
                           proc._build_map, 'fromimport')
 
     def test_name_collision(self):
@@ -1031,11 +1031,11 @@
 
         # All of these would try to create an object with the
         # same name as an existing object.
-        self.assertRaises(errors.ImportNameCollision,
+        self.assertRaises(lazy_import.ImportNameCollision,
                           proc._build_map, 'import bar as foo')
-        self.assertRaises(errors.ImportNameCollision,
+        self.assertRaises(lazy_import.ImportNameCollision,
                           proc._build_map, 'from foo import bar as foo')
-        self.assertRaises(errors.ImportNameCollision,
+        self.assertRaises(lazy_import.ImportNameCollision,
                           proc._build_map, 'from bar import foo')
 
     def test_relative_imports(self):
 
=== modified file 'breezy/trace.py'
--- breezy/trace.py	2019-07-13 14:35:12 +0000
+++ breezy/trace.py	2020-01-11 17:50:43 +0000
@@ -74,11 +74,13 @@
 from breezy import (
     bedding,
     debug,
-    errors,
     osutils,
     ui,
     )
 """)
+from . import (
+    errors,
+    )
 
 from .sixish import (
     PY3,
 
=== modified file 'breezy/transport/http/__init__.py'
--- breezy/transport/http/__init__.py	2020-01-10 02:20:50 +0000
+++ breezy/transport/http/__init__.py	2020-01-11 17:50:43 +0000
@@ -1037,6 +1037,9 @@
             newurl = headers.get('uri')
         else:
             return
+
+        newurl = urljoin(req.get_full_url(), newurl)
+
         if self._debuglevel >= 1:
             print('Redirected to: %s (followed: %r)' % (newurl,
                                                         req.follow_redirections))
@@ -1044,8 +1047,6 @@
             req.redirected_to = newurl
             return fp
 
-        newurl = urljoin(req.get_full_url(), newurl)
-
         # This call succeeds or raise an error. urllib_request returns
         # if redirect_request returns None, but our
         # redirect_request never returns None.
@@ -1830,6 +1831,7 @@
                        400,
                        403,
                        404,  # Not found
+                       405,  # Method not allowed
                        416,
                        422,
                        501,  # Not implemented
@@ -2018,6 +2020,10 @@
                 return self._actual.code
 
             @property
+            def reason(self):
+                return self._actual.reason
+
+            @property
             def data(self):
                 if self._data is None:
                     self._data = self._actual.read()
@@ -2081,16 +2087,28 @@
             if range_header is not None:
                 bytes = 'bytes=' + range_header
                 headers = {'Range': bytes}
+        else:
+            range_header = None
 
         response = self.request('GET', abspath, headers=headers)
 
         if response.status == 404:  # not found
             raise errors.NoSuchFile(abspath)
-        elif response.status in (400, 416):
+        elif response.status == 416:
             # We don't know which, but one of the ranges we specified was
             # wrong.
             raise errors.InvalidHttpRange(abspath, range_header,
                                           'Server return code %d' % response.status)
+        elif response.status == 400:
+            if range_header:
+                # We don't know which, but one of the ranges we specified was
+                # wrong.
+                raise errors.InvalidHttpRange(
+                    abspath, range_header,
+                    'Server return code %d' % response.status)
+            else:
+                raise errors.InvalidHttpResponse(
+                    abspath, 'Unexpected status %d' % response.status)
         elif response.status not in (200, 206):
             raise errors.InvalidHttpResponse(
                 abspath, 'Unexpected status %d' % response.status)
 
=== modified file 'breezy/workingtree.py'
--- breezy/workingtree.py	2020-01-10 01:37:30 +0000
+++ breezy/workingtree.py	2020-01-11 17:50:43 +0000
@@ -43,7 +43,6 @@
 from breezy import (
     cleanup,
     conflicts as _mod_conflicts,
-    errors,
     filters as _mod_filters,
     merge,
     revision as _mod_revision,
@@ -56,6 +55,9 @@
     )
 """)
 
+from . import (
+    errors,
+    )
 from .controldir import (
     ControlComponent,
     ControlComponentFormatRegistry,
 
=== modified file 'doc/en/release-notes/brz-3.1.txt'
--- doc/en/release-notes/brz-3.1.txt	2020-01-02 11:31:03 +0000
+++ doc/en/release-notes/brz-3.1.txt	2020-01-11 17:50:43 +0000
@@ -46,6 +46,10 @@
    have installed and speeds up import time since psutil brings in
    various other modules. (Jelmer Vernooij)
 
+ * Add a basic Mercurial plugin that mentions that .hg repositories
+   are unsupported when the user attempts to access one.
+   (Jelmer Vernooij)
+
  * The ``2a`` format now officially supports storing tree references.
    It always partially supported storing tree reference data,
    and would happily pull in tree reference data from other repository