diff --git a/.lgtm.yml b/.lgtm.yml
new file mode 100644
index 000000000..efc2479ca
--- /dev/null
+++ b/.lgtm.yml
@@ -0,0 +1,22 @@
+extraction:
+  python:
+    after_prepare:
+      - |
+        # https://discuss.lgtm.com/t/determination-of-python-requirements/974/4
+        sed -i 's/\("pyOpenSSL\)/\# Dependency removed for lgtm  (see .lgtm.yml): \1/g' src/allmydata/_auto_deps.py
+
+queries:
+  # This generates spurious errors for calls by interface because of the
+  # zope.interface choice to exclude self from method signatures.  So, turn it
+  # off.
+  - exclude: "py/call/wrong-arguments"
+
+  # The premise of this query is broken.  The errors it produces are nonsense.
+  # There is no such thing as a "procedure" in Python and "None" is not
+  # meaningless.
+  - exclude: "py/procedure-return-value-used"
+
+  # It is true that this query identifies things which are sometimes mistakes.
+  # However, it also identifies things which are entirely valid.  Therefore,
+  # it produces noisy results.
+  - exclude: "py/implicit-string-concatenation-in-list"
\ No newline at end of file
diff --git a/docs/proposed/magic-folder/filesystem-integration.rst b/docs/proposed/magic-folder/filesystem-integration.rst
index 6ed0671ed..589db2322 100644
--- a/docs/proposed/magic-folder/filesystem-integration.rst
+++ b/docs/proposed/magic-folder/filesystem-integration.rst
@@ -62,13 +62,15 @@ to the target folder cease for a sufficiently long period of time.
 
 *Detecting filesystem changes*
 
-For the Linux implementation, we will use the inotify Linux kernel
+For the Linux implementation, we will use the `inotify`_ Linux kernel
 subsystem to gather events on the local Magic Folder directory tree. This
 implementation was already present in Tahoe-LAFS 1.9.0, but needs to be
 changed to gather directory creation and move events, in addition to the
 events indicating that a file has been written that are gathered by the
 current code.
 
+.. _`inotify`: https://en.wikipedia.org/wiki/Inotify
+
 For the Windows implementation, we will use the ``ReadDirectoryChangesW``
 Win32 API. The prototype implementation simulates a Python interface to
 the inotify API in terms of ``ReadDirectoryChangesW``, allowing most of
diff --git a/misc/coding_tools/make-canary-files.py b/misc/coding_tools/make-canary-files.py
index 57f900a5c..4ba06cd9c 100644
--- a/misc/coding_tools/make-canary-files.py
+++ b/misc/coding_tools/make-canary-files.py
@@ -50,7 +50,7 @@ system where Tahoe is installed, or in a source tree with setup.py like this:
  setup.py run_with_pythonpath -p -c 'misc/make-canary-files.py ARGS..'
 """
 
-import os, sha
+import os, hashlib
 from twisted.python import usage
 from allmydata.immutable import upload
 from allmydata.util import base32
@@ -96,7 +96,7 @@ convergence = base32.a2b(convergence_s)
 def get_permuted_peers(key):
     results = []
     for nodeid in nodes:
-        permuted = sha.new(key + nodeid).digest()
+        permuted = hashlib.sha1(key + nodeid).digest()
         results.append((permuted, nodeid))
     results.sort(lambda a,b: cmp(a[0], b[0]))
     return [ r[1] for r in results ]
diff --git a/misc/operations_helpers/munin/tahoe_nodememory b/misc/operations_helpers/munin/tahoe_nodememory
index fd3f8b0a4..1ecf53fc9 100644
--- a/misc/operations_helpers/munin/tahoe_nodememory
+++ b/misc/operations_helpers/munin/tahoe_nodememory
@@ -6,10 +6,9 @@
 
 import os, sys, re
 
-if 0:
-    # for testing
-    os.environ["nodememory_warner1"] = "run/warner1"
-    os.environ["nodememory_warner2"] = "run/warner2"
+# for testing
+# os.environ["nodememory_warner1"] = "run/warner1"
+# os.environ["nodememory_warner2"] = "run/warner2"
 
 nodedirs = []
 for k,v in os.environ.items():
diff --git a/misc/simulators/simulator.py b/misc/simulators/simulator.py
index c1f9e9b54..a01c5c8c8 100644
--- a/misc/simulators/simulator.py
+++ b/misc/simulators/simulator.py
@@ -1,6 +1,6 @@
 #! /usr/bin/env python
 
-import sha as shamodule
+import hashlib
 import os, random
 
 from pkg_resources import require
@@ -10,7 +10,7 @@ from pyrrd.rrd import DataSource, RRD, RRA
 
 
 def sha(s):
-    return shamodule.new(s).digest()
+    return hashlib.sha1(s).digest()
 
 def randomid():
     return os.urandom(20)
@@ -70,10 +70,7 @@ class Node:
             return False
 
     def decide(self, sharesize):
-        if sharesize > self.capacity:
-            return False
         return False
-        return random.random() > 0.5
 
     def make_space(self, sharesize):
         assert sharesize <= self.capacity
diff --git a/src/allmydata/client.py b/src/allmydata/client.py
index 341ada081..71397f961 100644
--- a/src/allmydata/client.py
+++ b/src/allmydata/client.py
@@ -593,23 +593,7 @@ class _Client(node.Node, pollmixin.PollMixin):
 
             for (name, mf_config) in magic_folders.items():
                 self.log("Starting magic_folder '{}'".format(name))
-                db_filename = os.path.join(self.basedir, "private", "magicfolder_{}.sqlite".format(name))
-                local_dir_config = mf_config['directory']
-                try:
-                    poll_interval = int(mf_config["poll_interval"])
-                except ValueError:
-                    raise ValueError("'poll_interval' option must be an int")
-
-                s = magic_folder.MagicFolder(
-                    client=self,
-                    upload_dircap=mf_config["upload_dircap"].encode('ascii'),
-                    collective_dircap=mf_config["collective_dircap"].encode('ascii'),
-                    local_path_u=abspath_expanduser_unicode(local_dir_config, base=self.basedir),
-                    dbfile=abspath_expanduser_unicode(db_filename),
-                    umask=self.get_config("magic_folder", "download.umask", 0077),
-                    name=name,
-                    downloader_delay=poll_interval,
-                )
+                s = magic_folder.MagicFolder.from_config(self, name, mf_config)
                 self._magic_folders[name] = s
                 s.setServiceParent(self)
                 s.startService()
diff --git a/src/allmydata/frontends/magic_folder.py b/src/allmydata/frontends/magic_folder.py
index 5727a5343..24fd9cb0f 100644
--- a/src/allmydata/frontends/magic_folder.py
+++ b/src/allmydata/frontends/magic_folder.py
@@ -18,7 +18,12 @@ from zope.interface import Interface, Attribute, implementer
 from allmydata.util import fileutil, configutil, yamlutil
 from allmydata.interfaces import IDirectoryNode
 from allmydata.util import log
-from allmydata.util.fileutil import precondition_abspath, get_pathinfo, ConflictError
+from allmydata.util.fileutil import (
+    precondition_abspath,
+    get_pathinfo,
+    ConflictError,
+    abspath_expanduser_unicode,
+)
 from allmydata.util.assertutil import precondition, _assert
 from allmydata.util.deferredutil import HookMixin
 from allmydata.util.progress import PercentProgress
@@ -30,6 +35,9 @@ from allmydata.immutable.upload import FileName, Data
 from allmydata import magicfolderdb, magicpath
 
 
+# Mask off all non-owner permissions for magic-folders files by default.
+_DEFAULT_DOWNLOAD_UMASK = 0o077
+
 IN_EXCL_UNLINK = 0x04000000L
 
 def get_inotify_module():
@@ -119,6 +127,7 @@ def load_magic_folders(node_directory):
     old-style to new-style config (but WILL read old-style config and
     return in the same way as if it was new-style).
 
+    :param node_directory: path where node data is stored
     :returns: dict mapping magic-folder-name to its config (also a dict)
     """
     yaml_fname = os.path.join(node_directory, u"private", u"magic_folders.yaml")
@@ -156,11 +165,17 @@ def load_magic_folders(node_directory):
                     )
                 )
 
+            if config.has_option("magic_folder", "download.umask"):
+                umask = int(config.get("magic_folder", "download.umask"), 8)
+            else:
+                umask = _DEFAULT_DOWNLOAD_UMASK
+
             folders[u"default"] = {
                 u"directory": directory,
                 u"upload_dircap": fileutil.read(up_fname),
                 u"collective_dircap": fileutil.read(coll_fname),
                 u"poll_interval": interval,
+                u"umask": umask,
             }
         else:
             # without any YAML file AND no local.directory option it's
@@ -212,6 +227,12 @@ def load_magic_folders(node_directory):
             if isinstance(mf_config[k], unicode):
                 mf_config[k] = mf_config[k].encode('ascii')
 
+        if not isinstance(
+            mf_config.setdefault(u"umask", _DEFAULT_DOWNLOAD_UMASK),
+            int,
+        ):
+            raise Exception("magic-folder download umask must be an integer")
+
     return folders
 
 
@@ -228,6 +249,43 @@ def save_magic_folders(node_directory, folders):
 
 class MagicFolder(service.MultiService):
 
+    @classmethod
+    def from_config(cls, client_node, name, config):
+        """
+        Create a ``MagicFolder`` from a client node and magic-folder
+        configuration.
+
+        :param _Client client_node: The client node the magic-folder is
+            attached to.
+
+        :param dict config: Magic-folder configuration like that in the list
+            returned by ``load_magic_folders``.
+        """
+        db_filename = os.path.join(
+            client_node.basedir,
+            "private",
+            "magicfolder_{}.sqlite".format(name),
+        )
+        local_dir_config = config['directory']
+        try:
+            poll_interval = int(config["poll_interval"])
+        except ValueError:
+            raise ValueError("'poll_interval' option must be an int")
+
+        return cls(
+            client=client_node,
+            upload_dircap=config["upload_dircap"],
+            collective_dircap=config["collective_dircap"],
+            local_path_u=abspath_expanduser_unicode(
+                local_dir_config,
+                base=client_node.basedir,
+            ),
+            dbfile=abspath_expanduser_unicode(db_filename),
+            umask=config["umask"],
+            name=name,
+            downloader_delay=poll_interval,
+        )
+
     def __init__(self, client, upload_dircap, collective_dircap, local_path_u, dbfile, umask,
                  name, uploader_delay=1.0, clock=None, downloader_delay=60):
         precondition_abspath(local_path_u)
diff --git a/src/allmydata/frontends/sftpd.py b/src/allmydata/frontends/sftpd.py
index 028ea7ee5..83d1e540a 100644
--- a/src/allmydata/frontends/sftpd.py
+++ b/src/allmydata/frontends/sftpd.py
@@ -38,24 +38,9 @@ from allmydata.dirnode import update_metadata
 from allmydata.util.fileutil import EncryptedTemporaryFile
 
 noisy = True
-use_foolscap_logging = True
 
 from allmydata.util.log import NOISY, OPERATIONAL, WEIRD, \
-    msg as _msg, err as _err, PrefixingLogMixin as _PrefixingLogMixin
-
-if use_foolscap_logging:
-    (logmsg, logerr, PrefixingLogMixin) = (_msg, _err, _PrefixingLogMixin)
-else:  # pragma: no cover
-    def logmsg(s, level=None):
-        print s
-    def logerr(s, level=None):
-        print s
-    class PrefixingLogMixin:
-        def __init__(self, facility=None, prefix=''):
-            self.prefix = prefix
-        def log(self, s, level=None):
-            print "%r %s" % (self.prefix, s)
-
+    msg as logmsg, PrefixingLogMixin
 
 def eventually_callback(d):
     return lambda res: eventually(d.callback, res)
diff --git a/src/allmydata/immutable/layout.py b/src/allmydata/immutable/layout.py
index c634702ab..320f742e0 100644
--- a/src/allmydata/immutable/layout.py
+++ b/src/allmydata/immutable/layout.py
@@ -438,9 +438,7 @@ class ReadBucketProxy(object):
     def _get_share_hashes(self, unused=None):
         if hasattr(self, '_share_hashes'):
             return self._share_hashes
-        else:
-            return self._get_share_hashes_the_old_way()
-        return self._share_hashes
+        return self._get_share_hashes_the_old_way()
 
     def get_share_hashes(self):
         d = self._start_if_needed()
diff --git a/src/allmydata/immutable/upload.py b/src/allmydata/immutable/upload.py
index cef226a8e..26d0af30d 100644
--- a/src/allmydata/immutable/upload.py
+++ b/src/allmydata/immutable/upload.py
@@ -533,7 +533,6 @@ class Tahoe2ServerSelector(log.PrefixingLogMixin):
                 # we haven't improved over the last iteration; give up
                 break;
             if errors_before == self._query_stats.bad:
-                if False: print("no more errors; break")
                 break;
             last_happiness = effective_happiness
             # print("write trackers left: {}".format(len(write_trackers)))
diff --git a/src/allmydata/mutable/publish.py b/src/allmydata/mutable/publish.py
index ee17847e4..50db1e2e3 100644
--- a/src/allmydata/mutable/publish.py
+++ b/src/allmydata/mutable/publish.py
@@ -909,9 +909,7 @@ class Publish:
                  level=log.NOISY)
 
     def update_goal(self):
-        # if log.recording_noisy
-        if True:
-            self.log_goal(self.goal, "before update: ")
+        self.log_goal(self.goal, "before update: ")
 
         # first, remove any bad servers from our goal
         self.goal = set([ (server, shnum)
@@ -976,8 +974,7 @@ class Publish:
             i += 1
             if i >= len(serverlist):
                 i = 0
-        if True:
-            self.log_goal(self.goal, "after update: ")
+        self.log_goal(self.goal, "after update: ")
 
 
     def _got_write_answer(self, answer, writer, started):
diff --git a/src/allmydata/scripts/runner.py b/src/allmydata/scripts/runner.py
index d616cf199..70ff75bf2 100644
--- a/src/allmydata/scripts/runner.py
+++ b/src/allmydata/scripts/runner.py
@@ -47,7 +47,6 @@ class Options(usage.Options):
     stdout = sys.stdout
     stderr = sys.stderr
 
-    synopsis = "\nUsage:  tahoe <command> [command options]"
     subCommands = ( GROUP("Administration")
                     +   create_node.subCommands
                     +   stats_gatherer.subCommands
diff --git a/src/allmydata/test/test_client.py b/src/allmydata/test/test_client.py
index cf1d92b7b..b99769d3c 100644
--- a/src/allmydata/test/test_client.py
+++ b/src/allmydata/test/test_client.py
@@ -401,11 +401,18 @@ class Basic(testutil.ReallyEqualMixin, testutil.NonASCIIPathMixin, unittest.Test
         _check("helper.furl = pb://blah\n", "pb://blah")
 
     def test_create_magic_folder_service(self):
-        class MockMagicFolder(service.MultiService):
+        boom = False
+        class Boom(Exception):
+            pass
+
+        class MockMagicFolder(allmydata.frontends.magic_folder.MagicFolder):
             name = 'magic-folder'
 
             def __init__(self, client, upload_dircap, collective_dircap, local_path_u, dbfile, umask, name,
                          inotify=None, uploader_delay=1.0, clock=None, downloader_delay=3):
+                if boom:
+                    raise Boom()
+
                 service.MultiService.__init__(self)
                 self.client = client
                 self._umask = umask
@@ -415,6 +422,12 @@ class Basic(testutil.ReallyEqualMixin, testutil.NonASCIIPathMixin, unittest.Test
                 self.dbfile = dbfile
                 self.inotify = inotify
 
+            def startService(self):
+                self.running = True
+
+            def stopService(self):
+                self.running = False
+
             def ready(self):
                 pass
 
@@ -461,12 +474,8 @@ class Basic(testutil.ReallyEqualMixin, testutil.NonASCIIPathMixin, unittest.Test
         self.failUnless(magicfolder.inotify is None, magicfolder.inotify)
         self.failUnless(magicfolder.running)
 
-        class Boom(Exception):
-            pass
-        def BoomMagicFolder(client, upload_dircap, collective_dircap, local_path_u, dbfile, name,
-                            umask, inotify=None, uploader_delay=1.0, clock=None, downloader_delay=3):
-            raise Boom()
-        self.patch(allmydata.frontends.magic_folder, 'MagicFolder', BoomMagicFolder)
+        # See above.
+        boom = True
 
         basedir2 = "test_client.Basic.test_create_magic_folder_service2"
         os.mkdir(basedir2)
diff --git a/src/allmydata/test/test_magic_folder.py b/src/allmydata/test/test_magic_folder.py
index 451545584..0f26c99f2 100644
--- a/src/allmydata/test/test_magic_folder.py
+++ b/src/allmydata/test/test_magic_folder.py
@@ -65,6 +65,7 @@ class NewConfigUtilTests(unittest.TestCase):
     def test_load(self):
         folders = magic_folder.load_magic_folders(self.basedir)
         self.assertEqual(['default'], list(folders.keys()))
+        self.assertEqual(folders['default'][u'umask'], 0o077)
 
     def test_both_styles_of_config(self):
         os.unlink(join(self.basedir, u"private", u"magic_folders.yaml"))
@@ -115,6 +116,23 @@ class NewConfigUtilTests(unittest.TestCase):
             str(ctx.exception)
         )
 
+    def test_wrong_umask_obj(self):
+        """
+        If a umask is given for a magic-folder that is not an integer, an
+        exception is raised.
+        """
+        self.folders[u"default"][u"umask"] = "0077"
+        yaml_fname = join(self.basedir, u"private", u"magic_folders.yaml")
+        with open(yaml_fname, "w") as f:
+            f.write(yamlutil.safe_dump({u"magic-folders": self.folders}))
+
+        with self.assertRaises(Exception) as ctx:
+            magic_folder.load_magic_folders(self.basedir)
+        self.assertIn(
+            "umask must be an integer",
+            str(ctx.exception)
+        )
+
     def test_wrong_sub_obj(self):
         yaml_fname = join(self.basedir, u"private", u"magic_folders.yaml")
         with open(yaml_fname, "w") as f:
diff --git a/src/allmydata/util/encodingutil.py b/src/allmydata/util/encodingutil.py
index 65f5911a1..11ab942b6 100644
--- a/src/allmydata/util/encodingutil.py
+++ b/src/allmydata/util/encodingutil.py
@@ -335,8 +335,8 @@ def listdir_unicode_fallback(path):
 
     try:
         return [unicode(fn, filesystem_encoding) for fn in os.listdir(byte_path)]
-    except UnicodeDecodeError:
-        raise FilenameEncodingError(fn)
+    except UnicodeDecodeError as e:
+        raise FilenameEncodingError(e.object)
 
 def listdir_unicode(path):
     """
diff --git a/src/allmydata/util/tor_provider.py b/src/allmydata/util/tor_provider.py
index ccb963775..14d871cd0 100644
--- a/src/allmydata/util/tor_provider.py
+++ b/src/allmydata/util/tor_provider.py
@@ -72,13 +72,9 @@ def _launch_tor(reactor, tor_executable, private_dir, txtorcon):
     tor_config = txtorcon.TorConfig()
     tor_config.DataDirectory = data_directory(private_dir)
 
-    if True: # unix-domain control socket
-        tor_config.ControlPort = "unix:" + os.path.join(private_dir, "tor.control")
-        tor_control_endpoint_desc = tor_config.ControlPort
-    else:
-        # we allocate a new TCP control port each time
-        tor_config.ControlPort = allocate_tcp_port()
-        tor_control_endpoint_desc = "tcp:127.0.0.1:%d" % tor_config.ControlPort
+    # unix-domain control socket
+    tor_config.ControlPort = "unix:" + os.path.join(private_dir, "tor.control")
+    tor_control_endpoint_desc = tor_config.ControlPort
 
     tor_config.SOCKSPort = allocate_tcp_port()
 
diff --git a/src/allmydata/util/verlib.py b/src/allmydata/util/verlib.py
index 6d8d8e254..619f1a845 100644
--- a/src/allmydata/util/verlib.py
+++ b/src/allmydata/util/verlib.py
@@ -254,7 +254,7 @@ def suggest_normalized_version(s):
     # if we have something like "b-2" or "a.2" at the end of the
     # version, that is pobably beta, alpha, etc
     # let's remove the dash or dot
-    rs = re.sub(r"([abc|rc])[\-\.](\d+)$", r"\1\2", rs)
+    rs = re.sub(r"([abc]|rc)[\-\.](\d+)$", r"\1\2", rs)
 
     # 1.0-dev-r371 -> 1.0.dev371
     # 0.1-dev-r79 -> 0.1.dev79
@@ -324,4 +324,3 @@ def suggest_normalized_version(s):
     except IrrationalVersionError:
         pass
     return None
-
diff --git a/src/allmydata/web/directory.py b/src/allmydata/web/directory.py
index f21e1dffa..1cfd7a17b 100644
--- a/src/allmydata/web/directory.py
+++ b/src/allmydata/web/directory.py
@@ -74,8 +74,6 @@ class DirectoryNodeHandler(RenderMixin, rend.Page, ReplaceMeMixin):
         return d
 
     def got_child(self, node_or_failure, ctx, name):
-        DEBUG = False
-        if DEBUG: print "GOT_CHILD", name, node_or_failure
         req = IRequest(ctx)
         method = req.method
         nonterminal = len(req.postpath) > 1
@@ -84,24 +82,18 @@ class DirectoryNodeHandler(RenderMixin, rend.Page, ReplaceMeMixin):
             f = node_or_failure
             f.trap(NoSuchChildError)
             # No child by this name. What should we do about it?
-            if DEBUG: print "no child", name
-            if DEBUG: print "postpath", req.postpath
             if nonterminal:
-                if DEBUG: print " intermediate"
                 if should_create_intermediate_directories(req):
                     # create intermediate directories
-                    if DEBUG: print " making intermediate directory"
                     d = self.node.create_subdirectory(name)
                     d.addCallback(make_handler_for,
                                   self.client, self.node, name)
                     return d
             else:
-                if DEBUG: print " terminal"
                 # terminal node
                 if (method,t) in [ ("POST","mkdir"), ("PUT","mkdir"),
                                    ("POST", "mkdir-with-children"),
                                    ("POST", "mkdir-immutable") ]:
-                    if DEBUG: print " making final directory"
                     # final directory
                     kids = {}
                     if t in ("mkdir-with-children", "mkdir-immutable"):
@@ -122,14 +114,12 @@ class DirectoryNodeHandler(RenderMixin, rend.Page, ReplaceMeMixin):
                                   self.client, self.node, name)
                     return d
                 if (method,t) in ( ("PUT",""), ("PUT","uri"), ):
-                    if DEBUG: print " PUT, making leaf placeholder"
                     # we were trying to find the leaf filenode (to put a new
                     # file in its place), and it didn't exist. That's ok,
                     # since that's the leaf node that we're about to create.
                     # We make a dummy one, which will respond to the PUT
                     # request by replacing itself.
                     return PlaceHolderNodeHandler(self.client, self.node, name)
-            if DEBUG: print " 404"
             # otherwise, we just return a no-such-child error
             return f
 
@@ -138,11 +128,9 @@ class DirectoryNodeHandler(RenderMixin, rend.Page, ReplaceMeMixin):
             if not IDirectoryNode.providedBy(node):
                 # we would have put a new directory here, but there was a
                 # file in the way.
-                if DEBUG: print "blocking"
                 raise WebError("Unable to create directory '%s': "
                                "a file was in the way" % name,
                                http.CONFLICT)
-        if DEBUG: print "good child"
         return make_handler_for(node, self.client, self.node, name)
 
     def render_DELETE(self, ctx):
diff --git a/src/allmydata/webish.py b/src/allmydata/webish.py
index a07fbb4f2..bd404bbd4 100644
--- a/src/allmydata/webish.py
+++ b/src/allmydata/webish.py
@@ -2,6 +2,10 @@ import re, time
 from twisted.application import service, strports, internet
 from twisted.web import http, static
 from twisted.internet import defer
+from twisted.internet.address import (
+    IPv4Address,
+    IPv6Address,
+)
 from nevow import appserver, inevow
 from allmydata.util import log, fileutil
 
@@ -118,16 +122,32 @@ class MyRequest(appserver.NevowRequest):
         if self._tahoe_request_had_error:
             error = " [ERROR]"
 
-        log.msg(format="web: %(clientip)s %(method)s %(uri)s %(code)s %(length)s%(error)s",
-                clientip=self.getClientIP(),
-                method=self.method,
-                uri=uri,
-                code=self.code,
-                length=(self.sentLength or "-"),
-                error=error,
-                facility="tahoe.webish",
-                level=log.OPERATIONAL,
-                )
+        log.msg(
+            format=(
+                "web: %(clientip)s %(method)s %(uri)s %(code)s "
+                "%(length)s%(error)s"
+            ),
+            clientip=_get_client_ip(self),
+            method=self.method,
+            uri=uri,
+            code=self.code,
+            length=(self.sentLength or "-"),
+            error=error,
+            facility="tahoe.webish",
+            level=log.OPERATIONAL,
+        )
+
+
+def _get_client_ip(request):
+    try:
+        get = request.getClientAddress
+    except AttributeError:
+        return request.getClientIP()
+    else:
+        client_addr = get()
+        if isinstance(client_addr, (IPv4Address, IPv6Address)):
+            return client_addr.host
+        return None
 
 
 class WebishServer(service.MultiService):
diff --git a/src/allmydata/windows/registry.py b/src/allmydata/windows/registry.py
index 2b87689b8..4801310d3 100644
--- a/src/allmydata/windows/registry.py
+++ b/src/allmydata/windows/registry.py
@@ -5,9 +5,9 @@ _AMD_KEY = r"Software\Allmydata"
 _BDIR_KEY = 'Base Dir Path'
 
 if sys.platform not in ('win32'):
-    raise ImportError, "registry cannot be used on non-windows systems"
     class WindowsError(Exception): # stupid voodoo to appease pyflakes
         pass
+    raise ImportError("registry cannot be used on non-windows systems")
 
 def get_registry_setting(key, name, _topkey=None):
     """