httppeer: detect redirect to URL without query string (issue5860)

197d10e157ce subtly changed the HTTP peer's handling of HTTP redirects.

Before that changeset, we instantiated an HTTP peer instance and
performed the capabilities lookup with that instance. The old code had
the following relevant properties:

1) The HTTP request layer would automatically follow HTTP redirects.
2) An encountered HTTP redirect would update a peer instance variable
   pointing to the repo URL.
3) The peer would automagically perform a "capabilities" command
   request if a caller requested capabilities but capabilities were
   not yet defined.

The first HTTP request issued by a peer is for ?cmd=capabilities. If
the server responds with an HTTP redirect to a ?cmd=capabilities URL,
the HTTP request layer automatically followed it, retrieved a valid
capabilities response, and the peer's base URL was updated
automatically so subsequent requests used the proper URL. In other
words, things "just worked."

In the case where the server redirected to a URL without the
?cmd=capabilities query string, the HTTP request layer would follow
the redirect and likely encounter HTML. The peer's base URL would be
updated and the unexpected Content-Type would raise a RepoError. We
would catch RepoError and immediately call between() (testing the case
for pre 0.9.1 servers not supporting the "capabilities" command). e.g.

    try:
        inst._fetchcaps()
    except error.RepoError:
        inst.between([(nullid, nullid)])

between() would eventually call into _callstream(). And _callstream()
made a call to self.capable('httpheader'). capable() would call
self.capabilities(), which would see that no capabilities were set
(because HTML was returned for that request) and call the "capabilities"
command to fetch capabilities. Because the base URL had been updated
from the redirect, this 2nd "capabilities" command would succeed and
the client would immediately call "between," which would also succeed.
The legacy handshake succeeded. Only because "capabilities" was
successfully executed as a side effect did the peer recognize that it
was talking to a modern server. In other words, this all appeared to
work accidentally.

After 197d10e157ce, we stopped calling the "capabilities" command on
the peer instance. Instead, we made the request via a low-level opener,
detected the redirect as part of response handling code, and passed the
redirected URL into the constructed peer instance.

For cases where the redirected URL included the query string, this
"just worked." But for cases where the redirected URL stripped the query
string, we threw RepoError and because we removed the "between" handshake
fallback, we fell through to the "is a static HTTP repo" check and
performed an HTTP request for .hg/requires.

While 197d10e157ce was marked as backwards incompatible, the only
intended backwards incompatible behavior was not performing the
"between" fallback. It was not realized that the "between" command
had the side-effect of recovering from an errant redirect that
dropped the query string.

This commit restores the previous behavior and allows clients to
handle a redirect that drops the query string. In the case where
the request is redirected and the query string is dropped, we raise
a special case of RepoError. We then catch this special exception in
the handshake code and perform another "capabilities" request against
the redirected URL. If that works, all is well. Otherwise, we fall back
to the "is a static HTTP repo" check.

The new code is arguably better than before 197d10e157ce, as it is
explicit about the expected behavior and we avoid performing a
"between" request, saving a server round trip.

Differential Revision: https://phab.mercurial-scm.org/D3433

mercurial/httppeer.py

@@ -1,961 +1,996 b''
 # httppeer.py - HTTP repository proxy classes for mercurial
 #
 # Copyright 2005, 2006 Matt Mackall <[e-mail]>
 # Copyright 2006 Vadim Gelfer <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import errno
 import io
 import os
 import socket
 import struct
 import tempfile
 import weakref
 
 from .i18n import _
 from .thirdparty import (
     cbor,
 )
 from . import (
     bundle2,
     error,
     httpconnection,
     pycompat,
     repository,
     statichttprepo,
     url as urlmod,
     util,
     wireprotoframing,
     wireprototypes,
     wireprotov1peer,
     wireprotov2peer,
     wireprotov2server,
 )
 from .utils import (
     interfaceutil,
 )
 
 httplib = util.httplib
 urlerr = util.urlerr
 urlreq = util.urlreq
 
 def encodevalueinheaders(value, header, limit):
     """Encode a string value into multiple HTTP headers.
 
     ``value`` will be encoded into 1 or more HTTP headers with the names
     ``header-<N>`` where ``<N>`` is an integer starting at 1. Each header
     name + value will be at most ``limit`` bytes long.
 
     Returns an iterable of 2-tuples consisting of header names and
     values as native strings.
     """
     # HTTP Headers are ASCII. Python 3 requires them to be unicodes,
     # not bytes. This function always takes bytes in as arguments.
     fmt = pycompat.strurl(header) + r'-%s'
     # Note: it is *NOT* a bug that the last bit here is a bytestring
     # and not a unicode: we're just getting the encoded length anyway,
     # and using an r-string to make it portable between Python 2 and 3
     # doesn't work because then the \r is a literal backslash-r
     # instead of a carriage return.
     valuelen = limit - len(fmt % r'000') - len(': \r\n')
     result = []
 
     n = 0
     for i in xrange(0, len(value), valuelen):
         n += 1
         result.append((fmt % str(n), pycompat.strurl(value[i:i + valuelen])))
 
     return result
 
 def _wraphttpresponse(resp):
     """Wrap an HTTPResponse with common error handlers.
 
     This ensures that any I/O from any consumer raises the appropriate
     error and messaging.
     """
     origread = resp.read
 
     class readerproxy(resp.__class__):
         def read(self, size=None):
             try:
                 return origread(size)
             except httplib.IncompleteRead as e:
                 # e.expected is an integer if length known or None otherwise.
                 if e.expected:
                     msg = _('HTTP request error (incomplete response; '
                             'expected %d bytes got %d)') % (e.expected,
                                                            len(e.partial))
                 else:
                     msg = _('HTTP request error (incomplete response)')
 
                 raise error.PeerTransportError(
                     msg,
                     hint=_('this may be an intermittent network failure; '
                            'if the error persists, consider contacting the '
                            'network or server operator'))
             except httplib.HTTPException as e:
                 raise error.PeerTransportError(
                     _('HTTP request error (%s)') % e,
                     hint=_('this may be an intermittent network failure; '
                            'if the error persists, consider contacting the '
                            'network or server operator'))
 
     resp.__class__ = readerproxy
 
 class _multifile(object):
     def __init__(self, *fileobjs):
         for f in fileobjs:
             if not util.safehasattr(f, 'length'):
                 raise ValueError(
                     '_multifile only supports file objects that '
                     'have a length but this one does not:', type(f), f)
         self._fileobjs = fileobjs
         self._index = 0
 
     @property
     def length(self):
         return sum(f.length for f in self._fileobjs)
 
     def read(self, amt=None):
         if amt <= 0:
             return ''.join(f.read() for f in self._fileobjs)
         parts = []
         while amt and self._index < len(self._fileobjs):
             parts.append(self._fileobjs[self._index].read(amt))
             got = len(parts[-1])
             if got < amt:
                 self._index += 1
             amt -= got
         return ''.join(parts)
 
     def seek(self, offset, whence=os.SEEK_SET):
         if whence != os.SEEK_SET:
             raise NotImplementedError(
                 '_multifile does not support anything other'
                 ' than os.SEEK_SET for whence on seek()')
         if offset != 0:
             raise NotImplementedError(
                 '_multifile only supports seeking to start, but that '
                 'could be fixed if you need it')
         for f in self._fileobjs:
             f.seek(0)
         self._index = 0
 
 def makev1commandrequest(ui, requestbuilder, caps, capablefn,
                          repobaseurl, cmd, args):
     """Make an HTTP request to run a command for a version 1 client.
 
     ``caps`` is a set of known server capabilities. The value may be
     None if capabilities are not yet known.
 
     ``capablefn`` is a function to evaluate a capability.
 
     ``cmd``, ``args``, and ``data`` define the command, its arguments, and
     raw data to pass to it.
     """
     if cmd == 'pushkey':
         args['data'] = ''
     data = args.pop('data', None)
     headers = args.pop('headers', {})
 
     ui.debug("sending %s command\n" % cmd)
     q = [('cmd', cmd)]
     headersize = 0
     # Important: don't use self.capable() here or else you end up
     # with infinite recursion when trying to look up capabilities
     # for the first time.
     postargsok = caps is not None and 'httppostargs' in caps
 
     # Send arguments via POST.
     if postargsok and args:
         strargs = urlreq.urlencode(sorted(args.items()))
         if not data:
             data = strargs
         else:
             if isinstance(data, bytes):
                 i = io.BytesIO(data)
                 i.length = len(data)
                 data = i
             argsio = io.BytesIO(strargs)
             argsio.length = len(strargs)
             data = _multifile(argsio, data)
         headers[r'X-HgArgs-Post'] = len(strargs)
     elif args:
         # Calling self.capable() can infinite loop if we are calling
         # "capabilities". But that command should never accept wire
         # protocol arguments. So this should never happen.
         assert cmd != 'capabilities'
         httpheader = capablefn('httpheader')
         if httpheader:
             headersize = int(httpheader.split(',', 1)[0])
 
         # Send arguments via HTTP headers.
         if headersize > 0:
             # The headers can typically carry more data than the URL.
             encargs = urlreq.urlencode(sorted(args.items()))
             for header, value in encodevalueinheaders(encargs, 'X-HgArg',
                                                       headersize):
                 headers[header] = value
         # Send arguments via query string (Mercurial <1.9).
         else:
             q += sorted(args.items())
 
     qs = '?%s' % urlreq.urlencode(q)
     cu = "%s%s" % (repobaseurl, qs)
     size = 0
     if util.safehasattr(data, 'length'):
         size = data.length
     elif data is not None:
         size = len(data)
     if data is not None and r'Content-Type' not in headers:
         headers[r'Content-Type'] = r'application/mercurial-0.1'
 
     # Tell the server we accept application/mercurial-0.2 and multiple
     # compression formats if the server is capable of emitting those
     # payloads.
     # Note: Keep this set empty by default, as client advertisement of
     # protocol parameters should only occur after the handshake.
     protoparams = set()
 
     mediatypes = set()
     if caps is not None:
         mt = capablefn('httpmediatype')
         if mt:
             protoparams.add('0.1')
             mediatypes = set(mt.split(','))
 
         protoparams.add('partial-pull')
 
     if '0.2tx' in mediatypes:
         protoparams.add('0.2')
 
     if '0.2tx' in mediatypes and capablefn('compression'):
         # We /could/ compare supported compression formats and prune
         # non-mutually supported or error if nothing is mutually supported.
         # For now, send the full list to the server and have it error.
         comps = [e.wireprotosupport().name for e in
                  util.compengines.supportedwireengines(util.CLIENTROLE)]
         protoparams.add('comp=%s' % ','.join(comps))
 
     if protoparams:
         protoheaders = encodevalueinheaders(' '.join(sorted(protoparams)),
                                             'X-HgProto',
                                             headersize or 1024)
         for header, value in protoheaders:
             headers[header] = value
 
     varyheaders = []
     for header in headers:
         if header.lower().startswith(r'x-hg'):
             varyheaders.append(header)
 
     if varyheaders:
         headers[r'Vary'] = r','.join(sorted(varyheaders))
 
     req = requestbuilder(pycompat.strurl(cu), data, headers)
 
     if data is not None:
         ui.debug("sending %d bytes\n" % size)
         req.add_unredirected_header(r'Content-Length', r'%d' % size)
 
     return req, cu, qs
 
 def _reqdata(req):
     """Get request data, if any. If no data, returns None."""
     if pycompat.ispy3:
         return req.data
     if not req.has_data():
         return None
     return req.get_data()
 
 def sendrequest(ui, opener, req):
     """Send a prepared HTTP request.
 
     Returns the response object.
     """
     if (ui.debugflag
         and ui.configbool('devel', 'debug.peer-request')):
         dbg = ui.debug
         line = 'devel-peer-request: %s\n'
         dbg(line % '%s %s' % (pycompat.bytesurl(req.get_method()),
                               pycompat.bytesurl(req.get_full_url())))
         hgargssize = None
 
         for header, value in sorted(req.header_items()):
             header = pycompat.bytesurl(header)
             value = pycompat.bytesurl(value)
             if header.startswith('X-hgarg-'):
                 if hgargssize is None:
                     hgargssize = 0
                 hgargssize += len(value)
             else:
                 dbg(line % '  %s %s' % (header, value))
 
         if hgargssize is not None:
             dbg(line % '  %d bytes of commands arguments in headers'
                 % hgargssize)
         data = _reqdata(req)
         if data is not None:
             length = getattr(data, 'length', None)
             if length is None:
                 length = len(data)
             dbg(line % '  %d bytes of data' % length)
 
         start = util.timer()
 
     try:
         res = opener.open(req)
     except urlerr.httperror as inst:
         if inst.code == 401:
             raise error.Abort(_('authorization failed'))
         raise
     except httplib.HTTPException as inst:
         ui.debug('http error requesting %s\n' %
                  util.hidepassword(req.get_full_url()))
         ui.traceback()
         raise IOError(None, inst)
     finally:
         if ui.configbool('devel', 'debug.peer-request'):
             dbg(line % '  finished in %.4f seconds (%d)'
                 % (util.timer() - start, res.code))
 
     # Insert error handlers for common I/O failures.
     _wraphttpresponse(res)
 
     return res
 
+class RedirectedRepoError(error.RepoError):
+    def __init__(self, msg, respurl):
+        super(RedirectedRepoError, self).__init__(msg)
+        self.respurl = respurl
+
 def parsev1commandresponse(ui, baseurl, requrl, qs, resp, compressible,
                            allowcbor=False):
     # record the url we got redirected to
+    redirected = False
     respurl = pycompat.bytesurl(resp.geturl())
     if respurl.endswith(qs):
         respurl = respurl[:-len(qs)]
+        qsdropped = False
+    else:
+        qsdropped = True
+
     if baseurl.rstrip('/') != respurl.rstrip('/'):
+        redirected = True
         if not ui.quiet:
             ui.warn(_('real URL is %s\n') % respurl)
 
     try:
         proto = pycompat.bytesurl(resp.getheader(r'content-type', r''))
     except AttributeError:
         proto = pycompat.bytesurl(resp.headers.get(r'content-type', r''))
 
     safeurl = util.hidepassword(baseurl)
     if proto.startswith('application/hg-error'):
         raise error.OutOfBandError(resp.read())
 
     # Pre 1.0 versions of Mercurial used text/plain and
     # application/hg-changegroup. We don't support such old servers.
     if not proto.startswith('application/mercurial-'):
         ui.debug("requested URL: '%s'\n" % util.hidepassword(requrl))
-        raise error.RepoError(
-            _("'%s' does not appear to be an hg repository:\n"
-              "---%%<--- (%s)\n%s\n---%%<---\n")
-            % (safeurl, proto or 'no content-type', resp.read(1024)))
+        msg = _("'%s' does not appear to be an hg repository:\n"
+                "---%%<--- (%s)\n%s\n---%%<---\n") % (
+            safeurl, proto or 'no content-type', resp.read(1024))
+
+        # Some servers may strip the query string from the redirect. We
+        # raise a special error type so callers can react to this specially.
+        if redirected and qsdropped:
+            raise RedirectedRepoError(msg, respurl)
+        else:
+            raise error.RepoError(msg)
 
     try:
         subtype = proto.split('-', 1)[1]
 
         # Unless we end up supporting CBOR in the legacy wire protocol,
         # this should ONLY be encountered for the initial capabilities
         # request during handshake.
         if subtype == 'cbor':
             if allowcbor:
                 return respurl, proto, resp
             else:
                 raise error.RepoError(_('unexpected CBOR response from '
                                         'server'))
 
         version_info = tuple([int(n) for n in subtype.split('.')])
     except ValueError:
         raise error.RepoError(_("'%s' sent a broken Content-Type "
                                 "header (%s)") % (safeurl, proto))
 
     # TODO consider switching to a decompression reader that uses
     # generators.
     if version_info == (0, 1):
         if compressible:
             resp = util.compengines['zlib'].decompressorreader(resp)
 
     elif version_info == (0, 2):
         # application/mercurial-0.2 always identifies the compression
         # engine in the payload header.
         elen = struct.unpack('B', resp.read(1))[0]
         ename = resp.read(elen)
         engine = util.compengines.forwiretype(ename)
 
         resp = engine.decompressorreader(resp)
     else:
         raise error.RepoError(_("'%s' uses newer protocol %s") %
                               (safeurl, subtype))
 
     return respurl, proto, resp
 
 class httppeer(wireprotov1peer.wirepeer):
     def __init__(self, ui, path, url, opener, requestbuilder, caps):
         self.ui = ui
         self._path = path
         self._url = url
         self._caps = caps
         self._urlopener = opener
         self._requestbuilder = requestbuilder
 
     def __del__(self):
         for h in self._urlopener.handlers:
             h.close()
             getattr(h, "close_all", lambda: None)()
 
     # Begin of ipeerconnection interface.
 
     def url(self):
         return self._path
 
     def local(self):
         return None
 
     def peer(self):
         return self
 
     def canpush(self):
         return True
 
     def close(self):
         pass
 
     # End of ipeerconnection interface.
 
     # Begin of ipeercommands interface.
 
     def capabilities(self):
         return self._caps
 
     # End of ipeercommands interface.
 
-    # look up capabilities only when needed
-
     def _callstream(self, cmd, _compressible=False, **args):
         args = pycompat.byteskwargs(args)
 
         req, cu, qs = makev1commandrequest(self.ui, self._requestbuilder,
                                            self._caps, self.capable,
                                            self._url, cmd, args)
 
         resp = sendrequest(self.ui, self._urlopener, req)
 
         self._url, ct, resp = parsev1commandresponse(self.ui, self._url, cu, qs,
                                                      resp, _compressible)
 
         return resp
 
     def _call(self, cmd, **args):
         fp = self._callstream(cmd, **args)
         try:
             return fp.read()
         finally:
             # if using keepalive, allow connection to be reused
             fp.close()
 
     def _callpush(self, cmd, cg, **args):
         # have to stream bundle to a temp file because we do not have
         # http 1.1 chunked transfer.
 
         types = self.capable('unbundle')
         try:
             types = types.split(',')
         except AttributeError:
             # servers older than d1b16a746db6 will send 'unbundle' as a
             # boolean capability. They only support headerless/uncompressed
             # bundles.
             types = [""]
         for x in types:
             if x in bundle2.bundletypes:
                 type = x
                 break
 
         tempname = bundle2.writebundle(self.ui, cg, None, type)
         fp = httpconnection.httpsendfile(self.ui, tempname, "rb")
         headers = {r'Content-Type': r'application/mercurial-0.1'}
 
         try:
             r = self._call(cmd, data=fp, headers=headers, **args)
             vals = r.split('\n', 1)
             if len(vals) < 2:
                 raise error.ResponseError(_("unexpected response:"), r)
             return vals
         except urlerr.httperror:
             # Catch and re-raise these so we don't try and treat them
             # like generic socket errors. They lack any values in
             # .args on Python 3 which breaks our socket.error block.
             raise
         except socket.error as err:
             if err.args[0] in (errno.ECONNRESET, errno.EPIPE):
                 raise error.Abort(_('push failed: %s') % err.args[1])
             raise error.Abort(err.args[1])
         finally:
             fp.close()
             os.unlink(tempname)
 
     def _calltwowaystream(self, cmd, fp, **args):
         fh = None
         fp_ = None
         filename = None
         try:
             # dump bundle to disk
             fd, filename = tempfile.mkstemp(prefix="hg-bundle-", suffix=".hg")
             fh = os.fdopen(fd, r"wb")
             d = fp.read(4096)
             while d:
                 fh.write(d)
                 d = fp.read(4096)
             fh.close()
             # start http push
             fp_ = httpconnection.httpsendfile(self.ui, filename, "rb")
             headers = {r'Content-Type': r'application/mercurial-0.1'}
             return self._callstream(cmd, data=fp_, headers=headers, **args)
         finally:
             if fp_ is not None:
                 fp_.close()
             if fh is not None:
                 fh.close()
                 os.unlink(filename)
 
     def _callcompressable(self, cmd, **args):
         return self._callstream(cmd, _compressible=True, **args)
 
     def _abort(self, exception):
         raise exception
 
 def sendv2request(ui, opener, requestbuilder, apiurl, permission, requests):
     reactor = wireprotoframing.clientreactor(hasmultiplesend=False,
                                              buffersends=True)
 
     handler = wireprotov2peer.clienthandler(ui, reactor)
 
     url = '%s/%s' % (apiurl, permission)
 
     if len(requests) > 1:
         url += '/multirequest'
     else:
         url += '/%s' % requests[0][0]
 
     for command, args, f in requests:
         assert not list(handler.callcommand(command, args, f))
 
     # TODO stream this.
     body = b''.join(map(bytes, handler.flushcommands()))
 
     # TODO modify user-agent to reflect v2
     headers = {
         r'Accept': wireprotov2server.FRAMINGTYPE,
         r'Content-Type': wireprotov2server.FRAMINGTYPE,
     }
 
     req = requestbuilder(pycompat.strurl(url), body, headers)
     req.add_unredirected_header(r'Content-Length', r'%d' % len(body))
 
     try:
         res = opener.open(req)
     except urlerr.httperror as e:
         if e.code == 401:
             raise error.Abort(_('authorization failed'))
 
         raise
     except httplib.HTTPException as e:
         ui.traceback()
         raise IOError(None, e)
 
     return handler, res
 
 class queuedcommandfuture(pycompat.futures.Future):
     """Wraps result() on command futures to trigger submission on call."""
 
     def result(self, timeout=None):
         if self.done():
             return pycompat.futures.Future.result(self, timeout)
 
         self._peerexecutor.sendcommands()
 
         # sendcommands() will restore the original __class__ and self.result
         # will resolve to Future.result.
         return self.result(timeout)
 
 @interfaceutil.implementer(repository.ipeercommandexecutor)
 class httpv2executor(object):
     def __init__(self, ui, opener, requestbuilder, apiurl, descriptor):
         self._ui = ui
         self._opener = opener
         self._requestbuilder = requestbuilder
         self._apiurl = apiurl
         self._descriptor = descriptor
         self._sent = False
         self._closed = False
         self._neededpermissions = set()
         self._calls = []
         self._futures = weakref.WeakSet()
         self._responseexecutor = None
         self._responsef = None
 
     def __enter__(self):
         return self
 
     def __exit__(self, exctype, excvalue, exctb):
         self.close()
 
     def callcommand(self, command, args):
         if self._sent:
             raise error.ProgrammingError('callcommand() cannot be used after '
                                          'commands are sent')
 
         if self._closed:
             raise error.ProgrammingError('callcommand() cannot be used after '
                                          'close()')
 
         # The service advertises which commands are available. So if we attempt
         # to call an unknown command or pass an unknown argument, we can screen
         # for this.
         if command not in self._descriptor['commands']:
             raise error.ProgrammingError(
                 'wire protocol command %s is not available' % command)
 
         cmdinfo = self._descriptor['commands'][command]
         unknownargs = set(args.keys()) - set(cmdinfo.get('args', {}))
 
         if unknownargs:
             raise error.ProgrammingError(
                 'wire protocol command %s does not accept argument: %s' % (
                     command, ', '.join(sorted(unknownargs))))
 
         self._neededpermissions |= set(cmdinfo['permissions'])
 
         # TODO we /could/ also validate types here, since the API descriptor
         # includes types...
 
         f = pycompat.futures.Future()
 
         # Monkeypatch it so result() triggers sendcommands(), otherwise result()
         # could deadlock.
         f.__class__ = queuedcommandfuture
         f._peerexecutor = self
 
         self._futures.add(f)
         self._calls.append((command, args, f))
 
         return f
 
     def sendcommands(self):
         if self._sent:
             return
 
         if not self._calls:
             return
 
         self._sent = True
 
         # Unhack any future types so caller sees a clean type and so we
         # break reference cycle.
         for f in self._futures:
             if isinstance(f, queuedcommandfuture):
                 f.__class__ = pycompat.futures.Future
                 f._peerexecutor = None
 
         # Mark the future as running and filter out cancelled futures.
         calls = [(command, args, f)
                  for command, args, f in self._calls
                  if f.set_running_or_notify_cancel()]
 
         # Clear out references, prevent improper object usage.
         self._calls = None
 
         if not calls:
             return
 
         permissions = set(self._neededpermissions)
 
         if 'push' in permissions and 'pull' in permissions:
             permissions.remove('pull')
 
         if len(permissions) > 1:
             raise error.RepoError(_('cannot make request requiring multiple '
                                     'permissions: %s') %
                                   _(', ').join(sorted(permissions)))
 
         permission = {
             'push': 'rw',
             'pull': 'ro',
         }[permissions.pop()]
 
         handler, resp = sendv2request(
             self._ui, self._opener, self._requestbuilder, self._apiurl,
             permission, calls)
 
         # TODO we probably want to validate the HTTP code, media type, etc.
 
         self._responseexecutor = pycompat.futures.ThreadPoolExecutor(1)
         self._responsef = self._responseexecutor.submit(self._handleresponse,
                                                         handler, resp)
 
     def close(self):
         if self._closed:
             return
 
         self.sendcommands()
 
         self._closed = True
 
         if not self._responsef:
             return
 
         try:
             self._responsef.result()
         finally:
             self._responseexecutor.shutdown(wait=True)
             self._responsef = None
             self._responseexecutor = None
 
             # If any of our futures are still in progress, mark them as
             # errored, otherwise a result() could wait indefinitely.
             for f in self._futures:
                 if not f.done():
                     f.set_exception(error.ResponseError(
                         _('unfulfilled command response')))
 
             self._futures = None
 
     def _handleresponse(self, handler, resp):
         # Called in a thread to read the response.
 
         while handler.readframe(resp):
             pass
 
 # TODO implement interface for version 2 peers
 @interfaceutil.implementer(repository.ipeerconnection,
                            repository.ipeercapabilities,
                            repository.ipeerrequests)
 class httpv2peer(object):
     def __init__(self, ui, repourl, apipath, opener, requestbuilder,
                  apidescriptor):
         self.ui = ui
 
         if repourl.endswith('/'):
             repourl = repourl[:-1]
 
         self._url = repourl
         self._apipath = apipath
         self._apiurl = '%s/%s' % (repourl, apipath)
         self._opener = opener
         self._requestbuilder = requestbuilder
         self._descriptor = apidescriptor
 
     # Start of ipeerconnection.
 
     def url(self):
         return self._url
 
     def local(self):
         return None
 
     def peer(self):
         return self
 
     def canpush(self):
         # TODO change once implemented.
         return False
 
     def close(self):
         pass
 
     # End of ipeerconnection.
 
     # Start of ipeercapabilities.
 
     def capable(self, name):
         # The capabilities used internally historically map to capabilities
         # advertised from the "capabilities" wire protocol command. However,
         # version 2 of that command works differently.
 
         # Maps to commands that are available.
         if name in ('branchmap', 'getbundle', 'known', 'lookup', 'pushkey'):
             return True
 
         # Other concepts.
         if name in ('bundle2',):
             return True
 
         return False
 
     def requirecap(self, name, purpose):
         if self.capable(name):
             return
 
         raise error.CapabilityError(
             _('cannot %s; client or remote repository does not support the %r '
               'capability') % (purpose, name))
 
     # End of ipeercapabilities.
 
     def _call(self, name, **args):
         with self.commandexecutor() as e:
             return e.callcommand(name, args).result()
 
     def commandexecutor(self):
         return httpv2executor(self.ui, self._opener, self._requestbuilder,
                               self._apiurl, self._descriptor)
 
 # Registry of API service names to metadata about peers that handle it.
 #
 # The following keys are meaningful:
 #
 # init
 #    Callable receiving (ui, repourl, servicepath, opener, requestbuilder,
 #                        apidescriptor) to create a peer.
 #
 # priority
 #    Integer priority for the service. If we could choose from multiple
 #    services, we choose the one with the highest priority.
 API_PEERS = {
     wireprototypes.HTTP_WIREPROTO_V2: {
         'init': httpv2peer,
         'priority': 50,
     },
 }
 
 def performhandshake(ui, url, opener, requestbuilder):
     # The handshake is a request to the capabilities command.
 
     caps = None
     def capable(x):
         raise error.ProgrammingError('should not be called')
 
     args = {}
 
     # The client advertises support for newer protocols by adding an
     # X-HgUpgrade-* header with a list of supported APIs and an
     # X-HgProto-* header advertising which serializing formats it supports.
     # We only support the HTTP version 2 transport and CBOR responses for
     # now.
     advertisev2 = ui.configbool('experimental', 'httppeer.advertise-v2')
 
     if advertisev2:
         args['headers'] = {
             r'X-HgProto-1': r'cbor',
         }
 
         args['headers'].update(
             encodevalueinheaders(' '.join(sorted(API_PEERS)),
                                  'X-HgUpgrade',
                                  # We don't know the header limit this early.
                                  # So make it small.
                                  1024))
 
     req, requrl, qs = makev1commandrequest(ui, requestbuilder, caps,
                                            capable, url, 'capabilities',
                                            args)
-
     resp = sendrequest(ui, opener, req)
 
-    respurl, ct, resp = parsev1commandresponse(ui, url, requrl, qs, resp,
-                                               compressible=False,
-                                               allowcbor=advertisev2)
+    # The server may redirect us to the repo root, stripping the
+    # ?cmd=capabilities query string from the URL. The server would likely
+    # return HTML in this case and ``parsev1commandresponse()`` would raise.
+    # We catch this special case and re-issue the capabilities request against
+    # the new URL.
+    #
+    # We should ideally not do this, as a redirect that drops the query
+    # string from the URL is arguably a server bug. (Garbage in, garbage out).
+    # However,  Mercurial clients for several years appeared to handle this
+    # issue without behavior degradation. And according to issue 5860, it may
+    # be a longstanding bug in some server implementations. So we allow a
+    # redirect that drops the query string to "just work."
+    try:
+        respurl, ct, resp = parsev1commandresponse(ui, url, requrl, qs, resp,
+                                                   compressible=False,
+                                                   allowcbor=advertisev2)
+    except RedirectedRepoError as e:
+        req, requrl, qs = makev1commandrequest(ui, requestbuilder, caps,
+                                               capable, e.respurl,
+                                               'capabilities', args)
+        resp = sendrequest(ui, opener, req)
+        respurl, ct, resp = parsev1commandresponse(ui, url, requrl, qs, resp,
+                                                   compressible=False,
+                                                   allowcbor=advertisev2)
 
     try:
         rawdata = resp.read()
     finally:
         resp.close()
 
     if not ct.startswith('application/mercurial-'):
         raise error.ProgrammingError('unexpected content-type: %s' % ct)
 
     if advertisev2:
         if ct == 'application/mercurial-cbor':
             try:
                 info = cbor.loads(rawdata)
             except cbor.CBORDecodeError:
                 raise error.Abort(_('error decoding CBOR from remote server'),
                                   hint=_('try again and consider contacting '
                                          'the server operator'))
 
         # We got a legacy response. That's fine.
         elif ct in ('application/mercurial-0.1', 'application/mercurial-0.2'):
             info = {
                 'v1capabilities': set(rawdata.split())
             }
 
         else:
             raise error.RepoError(
                 _('unexpected response type from server: %s') % ct)
     else:
         info = {
             'v1capabilities': set(rawdata.split())
         }
 
     return respurl, info
 
 def makepeer(ui, path, opener=None, requestbuilder=urlreq.request):
     """Construct an appropriate HTTP peer instance.
 
     ``opener`` is an ``url.opener`` that should be used to establish
     connections, perform HTTP requests.
 
     ``requestbuilder`` is the type used for constructing HTTP requests.
     It exists as an argument so extensions can override the default.
     """
     u = util.url(path)
     if u.query or u.fragment:
         raise error.Abort(_('unsupported URL component: "%s"') %
                           (u.query or u.fragment))
 
     # urllib cannot handle URLs with embedded user or passwd.
     url, authinfo = u.authinfo()
     ui.debug('using %s\n' % url)
 
     opener = opener or urlmod.opener(ui, authinfo)
 
     respurl, info = performhandshake(ui, url, opener, requestbuilder)
 
     # Given the intersection of APIs that both we and the server support,
     # sort by their advertised priority and pick the first one.
     #
     # TODO consider making this request-based and interface driven. For
     # example, the caller could say "I want a peer that does X." It's quite
     # possible that not all peers would do that. Since we know the service
     # capabilities, we could filter out services not meeting the
     # requirements. Possibly by consulting the interfaces defined by the
     # peer type.
     apipeerchoices = set(info.get('apis', {}).keys()) & set(API_PEERS.keys())
 
     preferredchoices = sorted(apipeerchoices,
                               key=lambda x: API_PEERS[x]['priority'],
                               reverse=True)
 
     for service in preferredchoices:
         apipath = '%s/%s' % (info['apibase'].rstrip('/'), service)
 
         return API_PEERS[service]['init'](ui, respurl, apipath, opener,
                                           requestbuilder,
                                           info['apis'][service])
 
     # Failed to construct an API peer. Fall back to legacy.
     return httppeer(ui, path, respurl, opener, requestbuilder,
                     info['v1capabilities'])
 
 def instance(ui, path, create, intents=None):
     if create:
         raise error.Abort(_('cannot create new http repository'))
     try:
         if path.startswith('https:') and not urlmod.has_https:
             raise error.Abort(_('Python support for SSL and HTTPS '
                                 'is not installed'))
 
         inst = makepeer(ui, path)
 
         return inst
     except error.RepoError as httpexception:
         try:
             r = statichttprepo.instance(ui, "static-" + path, create)
             ui.note(_('(falling back to static-http)\n'))
             return r
         except error.RepoError:
             raise httpexception # use the original http RepoError instead

tests/test-http-protocol.t

@@ -1,335 +1,726 b''
   $ . $TESTDIR/wireprotohelpers.sh
 
   $ cat >> $HGRCPATH << EOF
   > [web]
   > push_ssl = false
   > allow_push = *
   > EOF
 
   $ hg init server
   $ cd server
   $ touch a
   $ hg -q commit -A -m initial
   $ cd ..
 
   $ hg serve -R server -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid >> $DAEMON_PIDS
 
 compression formats are advertised in compression capability
 
 #if zstd
   $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=capabilities' | tr ' ' '\n' | grep '^compression=zstd,zlib$' > /dev/null
 #else
   $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=capabilities' | tr ' ' '\n' | grep '^compression=zlib$' > /dev/null
 #endif
 
   $ killdaemons.py
 
 server.compressionengines can replace engines list wholesale
 
   $ hg serve --config server.compressionengines=none -R server -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid > $DAEMON_PIDS
   $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=capabilities' | tr ' ' '\n' | grep '^compression=none$' > /dev/null
 
   $ killdaemons.py
 
 Order of engines can also change
 
   $ hg serve --config server.compressionengines=none,zlib -R server -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid > $DAEMON_PIDS
   $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=capabilities' | tr ' ' '\n' | grep '^compression=none,zlib$' > /dev/null
 
   $ killdaemons.py
 
 Start a default server again
 
   $ hg serve -R server -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid > $DAEMON_PIDS
 
 Server should send application/mercurial-0.1 to clients if no Accept is used
 
   $ get-with-headers.py --headeronly $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' -
   200 Script output follows
   content-type: application/mercurial-0.1
   date: $HTTP_DATE$
   server: testing stub value
   transfer-encoding: chunked
 
 Server should send application/mercurial-0.1 when client says it wants it
 
   $ get-with-headers.py --hgproto '0.1' --headeronly $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' -
   200 Script output follows
   content-type: application/mercurial-0.1
   date: $HTTP_DATE$
   server: testing stub value
   transfer-encoding: chunked
 
 Server should send application/mercurial-0.2 when client says it wants it
 
   $ get-with-headers.py --hgproto '0.2' --headeronly $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' -
   200 Script output follows
   content-type: application/mercurial-0.2
   date: $HTTP_DATE$
   server: testing stub value
   transfer-encoding: chunked
 
   $ get-with-headers.py --hgproto '0.1 0.2' --headeronly $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' -
   200 Script output follows
   content-type: application/mercurial-0.2
   date: $HTTP_DATE$
   server: testing stub value
   transfer-encoding: chunked
 
 Requesting a compression format that server doesn't support results will fall back to 0.1
 
   $ get-with-headers.py --hgproto '0.2 comp=aa' --headeronly $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' -
   200 Script output follows
   content-type: application/mercurial-0.1
   date: $HTTP_DATE$
   server: testing stub value
   transfer-encoding: chunked
 
 #if zstd
 zstd is used if available
 
   $ get-with-headers.py --hgproto '0.2 comp=zstd' $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' > resp
   $ f --size --hexdump --bytes 36 --sha1 resp
   resp: size=248, sha1=4d8d8f87fb82bd542ce52881fdc94f850748
   0000: 32 30 30 20 53 63 72 69 70 74 20 6f 75 74 70 75 |200 Script outpu|
   0010: 74 20 66 6f 6c 6c 6f 77 73 0a 0a 04 7a 73 74 64 |t follows...zstd|
   0020: 28 b5 2f fd                                     |(./.|
 
 #endif
 
 application/mercurial-0.2 is not yet used on non-streaming responses
 
   $ get-with-headers.py --hgproto '0.2' $LOCALIP:$HGPORT '?cmd=heads' -
   200 Script output follows
   content-length: 41
   content-type: application/mercurial-0.1
   date: $HTTP_DATE$
   server: testing stub value
   
   e93700bd72895c5addab234c56d4024b487a362f
 
 Now test protocol preference usage
 
   $ killdaemons.py
   $ hg serve --config server.compressionengines=none,zlib -R server -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid > $DAEMON_PIDS
 
 No Accept will send 0.1+zlib, even though "none" is preferred b/c "none" isn't supported on 0.1
 
   $ get-with-headers.py --headeronly $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000' Content-Type
   200 Script output follows
   content-type: application/mercurial-0.1
 
   $ get-with-headers.py $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000'  > resp
   $ f --size --hexdump --bytes 28 --sha1 resp
   resp: size=227, sha1=35a4c074da74f32f5440da3cbf04
   0000: 32 30 30 20 53 63 72 69 70 74 20 6f 75 74 70 75 |200 Script outpu|
   0010: 74 20 66 6f 6c 6c 6f 77 73 0a 0a 78             |t follows..x|
 
 Explicit 0.1 will send zlib because "none" isn't supported on 0.1
 
   $ get-with-headers.py --hgproto '0.1' $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000'  > resp
   $ f --size --hexdump --bytes 28 --sha1 resp
   resp: size=227, sha1=35a4c074da74f32f5440da3cbf04
   0000: 32 30 30 20 53 63 72 69 70 74 20 6f 75 74 70 75 |200 Script outpu|
   0010: 74 20 66 6f 6c 6c 6f 77 73 0a 0a 78             |t follows..x|
 
 0.2 with no compression will get "none" because that is server's preference
 (spec says ZL and UN are implicitly supported)
 
   $ get-with-headers.py --hgproto '0.2' $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000'  > resp
   $ f --size --hexdump --bytes 32 --sha1 resp
   resp: size=432, sha1=ac931b412ec185a02e0e5bcff98dac83
   0000: 32 30 30 20 53 63 72 69 70 74 20 6f 75 74 70 75 |200 Script outpu|
   0010: 74 20 66 6f 6c 6c 6f 77 73 0a 0a 04 6e 6f 6e 65 |t follows...none|
 
 Client receives server preference even if local order doesn't match
 
   $ get-with-headers.py --hgproto '0.2 comp=zlib,none' $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000'  > resp
   $ f --size --hexdump --bytes 32 --sha1 resp
   resp: size=432, sha1=ac931b412ec185a02e0e5bcff98dac83
   0000: 32 30 30 20 53 63 72 69 70 74 20 6f 75 74 70 75 |200 Script outpu|
   0010: 74 20 66 6f 6c 6c 6f 77 73 0a 0a 04 6e 6f 6e 65 |t follows...none|
 
 Client receives only supported format even if not server preferred format
 
   $ get-with-headers.py --hgproto '0.2 comp=zlib' $LOCALIP:$HGPORT '?cmd=getbundle&heads=e93700bd72895c5addab234c56d4024b487a362f&common=0000000000000000000000000000000000000000'  > resp
   $ f --size --hexdump --bytes 33 --sha1 resp
   resp: size=232, sha1=a1c727f0c9693ca15742a75c30419bc36
   0000: 32 30 30 20 53 63 72 69 70 74 20 6f 75 74 70 75 |200 Script outpu|
   0010: 74 20 66 6f 6c 6c 6f 77 73 0a 0a 04 7a 6c 69 62 |t follows...zlib|
   0020: 78                                              |x|
 
   $ killdaemons.py
   $ cd ..
 
 Test listkeys for listing namespaces
 
   $ hg init empty
   $ hg -R empty serve -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid > $DAEMON_PIDS
 
   $ hg --verbose debugwireproto http://$LOCALIP:$HGPORT << EOF
   > command listkeys
   >     namespace namespaces
   > EOF
   s>     GET /?cmd=capabilities HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-0.1\r\n
   s>     Content-Length: *\r\n (glob)
   s>     \r\n
   s>     batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
   sending listkeys command
   s>     GET /?cmd=listkeys HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     vary: X-HgArg-1,X-HgProto-1\r\n
   s>     x-hgarg-1: namespace=namespaces\r\n
   s>     x-hgproto-1: 0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-0.1\r\n
   s>     Content-Length: 30\r\n
   s>     \r\n
   s>     bookmarks\t\n
   s>     namespaces\t\n
   s>     phases\t
   response: {b'bookmarks': b'', b'namespaces': b'', b'phases': b''}
 
 Same thing, but with "httprequest" command
 
   $ hg --verbose debugwireproto --peer raw http://$LOCALIP:$HGPORT << EOF
   > httprequest GET ?cmd=listkeys
   >     user-agent: test
   >     x-hgarg-1: namespace=namespaces
   > EOF
   using raw connection to peer
   s>     GET /?cmd=listkeys HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     user-agent: test\r\n
   s>     x-hgarg-1: namespace=namespaces\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-0.1\r\n
   s>     Content-Length: 30\r\n
   s>     \r\n
   s>     bookmarks\t\n
   s>     namespaces\t\n
   s>     phases\t
 
 Client with HTTPv2 enabled advertises that and gets old capabilities response from old server
 
   $ hg --config experimental.httppeer.advertise-v2=true --verbose debugwireproto http://$LOCALIP:$HGPORT << EOF
   > command heads
   > EOF
   s>     GET /?cmd=capabilities HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     vary: X-HgProto-1,X-HgUpgrade-1\r\n
   s>     x-hgproto-1: cbor\r\n
   s>     x-hgupgrade-1: exp-http-v2-0001\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-0.1\r\n
   s>     Content-Length: *\r\n (glob)
   s>     \r\n
   s>     batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
   sending heads command
   s>     GET /?cmd=heads HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     vary: X-HgProto-1\r\n
   s>     x-hgproto-1: 0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 Script output follows\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-0.1\r\n
   s>     Content-Length: 41\r\n
   s>     \r\n
   s>     0000000000000000000000000000000000000000\n
   response: [b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00']
 
   $ killdaemons.py
   $ enablehttpv2 empty
   $ hg --config server.compressionengines=zlib -R empty serve -p $HGPORT -d --pid-file hg.pid
   $ cat hg.pid > $DAEMON_PIDS
 
 Client with HTTPv2 enabled automatically upgrades if the server supports it
 
   $ hg --config experimental.httppeer.advertise-v2=true --verbose debugwireproto http://$LOCALIP:$HGPORT << EOF
   > command heads
   > EOF
   s>     GET /?cmd=capabilities HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     vary: X-HgProto-1,X-HgUpgrade-1\r\n
   s>     x-hgproto-1: cbor\r\n
   s>     x-hgupgrade-1: exp-http-v2-0001\r\n
   s>     accept: application/mercurial-0.1\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s> makefile('rb', None)
   s>     HTTP/1.1 200 OK\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-cbor\r\n
   s>     Content-Length: *\r\n (glob)
   s>     \r\n
   s>     \xa3Dapis\xa1Pexp-http-v2-0001\xa4Hcommands\xa7Eheads\xa2Dargs\xa1Jpubliconly\xf4Kpermissions\x81DpullEknown\xa2Dargs\xa1Enodes\x81HdeadbeefKpermissions\x81DpullFlookup\xa2Dargs\xa1CkeyCfooKpermissions\x81DpullGpushkey\xa2Dargs\xa4CkeyCkeyCnewCnewColdColdInamespaceBnsKpermissions\x81DpushHlistkeys\xa2Dargs\xa1InamespaceBnsKpermissions\x81DpullIbranchmap\xa2Dargs\xa0Kpermissions\x81DpullLcapabilities\xa2Dargs\xa0Kpermissions\x81DpullKcompression\x81\xa1DnameDzlibNrawrepoformats\x82LgeneraldeltaHrevlogv1Qframingmediatypes\x81X&application/mercurial-exp-framing-0005GapibaseDapi/Nv1capabilitiesY\x01\xc5batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
   sending heads command
   s>     POST /api/exp-http-v2-0001/ro/heads HTTP/1.1\r\n
   s>     Accept-Encoding: identity\r\n
   s>     accept: application/mercurial-exp-framing-0005\r\n
   s>     content-type: application/mercurial-exp-framing-0005\r\n
   s>     content-length: 20\r\n
   s>     host: $LOCALIP:$HGPORT\r\n (glob)
   s>     user-agent: Mercurial debugwireproto\r\n
   s>     \r\n
   s>     \x0c\x00\x00\x01\x00\x01\x01\x11\xa1DnameEheads
   s> makefile('rb', None)
   s>     HTTP/1.1 200 OK\r\n
   s>     Server: testing stub value\r\n
   s>     Date: $HTTP_DATE$\r\n
   s>     Content-Type: application/mercurial-exp-framing-0005\r\n
   s>     Transfer-Encoding: chunked\r\n
   s>     \r\n
   s>     29\r\n
   s>     !\x00\x00\x01\x00\x02\x012
   s>     \xa1FstatusBok\x81T\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00
   s>     \r\n
   received frame(size=33; request=1; stream=2; streamflags=stream-begin; type=command-response; flags=eos)
   s>     0\r\n
   s>     \r\n
   response: [b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00']
 
   $ killdaemons.py
+
+HTTP client follows HTTP redirect on handshake to new repo
+
+  $ cd $TESTTMP
+
+  $ hg init redirector
+  $ hg init redirected
+  $ cd redirected
+  $ touch foo
+  $ hg -q commit -A -m initial
+  $ cd ..
+
+  $ cat > paths.conf << EOF
+  > [paths]
+  > / = $TESTTMP/*
+  > EOF
+
+  $ cat > redirectext.py << EOF
+  > from mercurial import extensions, wireprotoserver
+  > def wrappedcallhttp(orig, repo, req, res, proto, cmd):
+  >     path = req.advertisedurl[len(req.advertisedbaseurl):]
+  >     if not path.startswith(b'/redirector'):
+  >         return orig(repo, req, res, proto, cmd)
+  >     relpath = path[len(b'/redirector'):]
+  >     res.status = b'301 Redirect'
+  >     newurl = b'%s/redirected%s' % (req.baseurl, relpath)
+  >     if not repo.ui.configbool('testing', 'redirectqs', True) and b'?' in newurl:
+  >         newurl = newurl[0:newurl.index(b'?')]
+  >     res.headers[b'Location'] = newurl
+  >     res.headers[b'Content-Type'] = b'text/plain'
+  >     res.setbodybytes(b'redirected')
+  >     return True
+  > 
+  > extensions.wrapfunction(wireprotoserver, '_callhttp', wrappedcallhttp)
+  > EOF
+
+  $ hg --config extensions.redirect=$TESTTMP/redirectext.py \
+  >    --config server.compressionengines=zlib \
+  >     serve --web-conf paths.conf --pid-file hg.pid -p $HGPORT -d
+  $ cat hg.pid > $DAEMON_PIDS
+
+Verify our HTTP 301 is served properly
+
+  $ hg --verbose debugwireproto --peer raw http://$LOCALIP:$HGPORT << EOF
+  > httprequest GET /redirector?cmd=capabilities
+  >     user-agent: test
+  > EOF
+  using raw connection to peer
+  s>     GET /redirector?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     user-agent: test\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 301 Redirect\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Location: http://$LOCALIP:$HGPORT/redirected?cmd=capabilities\r\n (glob)
+  s>     Content-Type: text/plain\r\n
+  s>     Content-Length: 10\r\n
+  s>     \r\n
+  s>     redirected
+  s>     GET /redirected?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     user-agent: test\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-0.1\r\n
+  s>     Content-Length: 453\r\n
+  s>     \r\n
+  s>     batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
+
+Test with the HTTP peer
+
+  $ hg --verbose debugwireproto http://$LOCALIP:$HGPORT/redirector << EOF
+  > command heads
+  > EOF
+  s>     GET /redirector?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 301 Redirect\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Location: http://$LOCALIP:$HGPORT/redirected?cmd=capabilities\r\n (glob)
+  s>     Content-Type: text/plain\r\n
+  s>     Content-Length: 10\r\n
+  s>     \r\n
+  s>     redirected
+  s>     GET /redirected?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-0.1\r\n
+  s>     Content-Length: 453\r\n
+  s>     \r\n
+  real URL is http://$LOCALIP:$HGPORT/redirected (glob)
+  s>     batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
+  sending heads command
+  s>     GET /redirected?cmd=heads HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     vary: X-HgProto-1\r\n
+  s>     x-hgproto-1: 0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-0.1\r\n
+  s>     Content-Length: 41\r\n
+  s>     \r\n
+  s>     96ee1d7354c4ad7372047672c36a1f561e3a6a4c\n
+  response: [b'\x96\xee\x1dsT\xc4\xadsr\x04vr\xc3j\x1fV\x1e:jL']
+
+  $ killdaemons.py
+
+Now test a variation where we strip the query string from the redirect URL.
+(SCM Manager apparently did this and clients would recover from it)
+
+  $ hg --config extensions.redirect=$TESTTMP/redirectext.py \
+  >    --config server.compressionengines=zlib \
+  >    --config testing.redirectqs=false \
+  >     serve --web-conf paths.conf --pid-file hg.pid -p $HGPORT -d
+  $ cat hg.pid > $DAEMON_PIDS
+
+  $ hg --verbose debugwireproto --peer raw http://$LOCALIP:$HGPORT << EOF
+  > httprequest GET /redirector?cmd=capabilities
+  >     user-agent: test
+  > EOF
+  using raw connection to peer
+  s>     GET /redirector?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     user-agent: test\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 301 Redirect\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Location: http://$LOCALIP:$HGPORT/redirected\r\n (glob)
+  s>     Content-Type: text/plain\r\n
+  s>     Content-Length: 10\r\n
+  s>     \r\n
+  s>     redirected
+  s>     GET /redirected HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     user-agent: test\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     ETag: W/"*"\r\n (glob)
+  s>     Content-Type: text/html; charset=ascii\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  s>     414\r\n
+  s>     <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">\n
+  s>     <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">\n
+  s>     <head>\n
+  s>     <link rel="icon" href="/redirected/static/hgicon.png" type="image/png" />\n
+  s>     <meta name="robots" content="index, nofollow" />\n
+  s>     <link rel="stylesheet" href="/redirected/static/style-paper.css" type="text/css" />\n
+  s>     <script type="text/javascript" src="/redirected/static/mercurial.js"></script>\n
+  s>     \n
+  s>     <title>redirected: log</title>\n
+  s>     <link rel="alternate" type="application/atom+xml"\n
+  s>        href="/redirected/atom-log" title="Atom feed for redirected" />\n
+  s>     <link rel="alternate" type="application/rss+xml"\n
+  s>        href="/redirected/rss-log" title="RSS feed for redirected" />\n
+  s>     </head>\n
+  s>     <body>\n
+  s>     \n
+  s>     <div class="container">\n
+  s>     <div class="menu">\n
+  s>     <div class="logo">\n
+  s>     <a href="https://mercurial-scm.org/">\n
+  s>     <img src="/redirected/static/hglogo.png" alt="mercurial" /></a>\n
+  s>     </div>\n
+  s>     <ul>\n
+  s>     <li class="active">log</li>\n
+  s>     <li><a href="/redirected/graph/tip">graph</a></li>\n
+  s>     <li><a href="/redirected/tags">tags</a></li>\n
+  s>     <li><a href="
+  s>     \r\n
+  s>     810\r\n
+  s>     /redirected/bookmarks">bookmarks</a></li>\n
+  s>     <li><a href="/redirected/branches">branches</a></li>\n
+  s>     </ul>\n
+  s>     <ul>\n
+  s>     <li><a href="/redirected/rev/tip">changeset</a></li>\n
+  s>     <li><a href="/redirected/file/tip">browse</a></li>\n
+  s>     </ul>\n
+  s>     <ul>\n
+  s>     \n
+  s>     </ul>\n
+  s>     <ul>\n
+  s>      <li><a href="/redirected/help">help</a></li>\n
+  s>     </ul>\n
+  s>     <div class="atom-logo">\n
+  s>     <a href="/redirected/atom-log" title="subscribe to atom feed">\n
+  s>     <img class="atom-logo" src="/redirected/static/feed-icon-14x14.png" alt="atom feed" />\n
+  s>     </a>\n
+  s>     </div>\n
+  s>     </div>\n
+  s>     \n
+  s>     <div class="main">\n
+  s>     <h2 class="breadcrumb"><a href="/">Mercurial</a> &gt; <a href="/redirected">redirected</a> </h2>\n
+  s>     <h3>log</h3>\n
+  s>     \n
+  s>     \n
+  s>     <form class="search" action="/redirected/log">\n
+  s>     \n
+  s>     <p><input name="rev" id="search1" type="text" size="30" value="" /></p>\n
+  s>     <div id="hint">Find changesets by keywords (author, files, the commit message), revision\n
+  s>     number or hash, or <a href="/redirected/help/revsets">revset expression</a>.</div>\n
+  s>     </form>\n
+  s>     \n
+  s>     <div class="navigate">\n
+  s>     <a href="/redirected/shortlog/tip?revcount=30">less</a>\n
+  s>     <a href="/redirected/shortlog/tip?revcount=120">more</a>\n
+  s>     | rev 0: <a href="/redirected/shortlog/96ee1d7354c4">(0)</a> <a href="/redirected/shortlog/tip">tip</a> \n
+  s>     </div>\n
+  s>     \n
+  s>     <table class="bigtable">\n
+  s>     <thead>\n
+  s>      <tr>\n
+  s>       <th class="age">age</th>\n
+  s>       <th class="author">author</th>\n
+  s>       <th class="description">description</th>\n
+  s>      </tr>\n
+  s>     </thead>\n
+  s>     <tbody class="stripes2">\n
+  s>      <tr>\n
+  s>       <td class="age">Thu, 01 Jan 1970 00:00:00 +0000</td>\n
+  s>       <td class="author">test</td>\n
+  s>       <td class="description">\n
+  s>        <a href="/redirected/rev/96ee1d7354c4">initial</a>\n
+  s>        <span class="phase">draft</span> <span class="branchhead">default</span> <span class="tag">tip</span> \n
+  s>       </td>\n
+  s>      </tr>\n
+  s>     \n
+  s>     </tbody>\n
+  s>     </table>\n
+  s>     \n
+  s>     <div class="navigate">\n
+  s>     <a href="/redirected/shortlog/tip?revcount=30">less</a>\n
+  s>     <a href="/redirected/shortlog/tip?revcount=120">more</a>\n
+  s>     | rev 0: <a href="/redirected/shortlog/96ee1d7354c4">(0)</a> <a href="/redirected/shortlog/tip">tip</a> \n
+  s>     </div>\n
+  s>     \n
+  s>     <script type="text/javascript">\n
+  s>         ajaxScrollInit(\n
+  s>                 \'/redirected/shortlog/%next%\',\n
+  s>                 \'\', <!-- NEXTHASH\n
+  s>                 function (htmlText) {
+  s>     \r\n
+  s>     14a\r\n
+  s>     \n
+  s>                     var m = htmlText.match(/\'(\\w+)\', <!-- NEXTHASH/);\n
+  s>                     return m ? m[1] : null;\n
+  s>                 },\n
+  s>                 \'.bigtable > tbody\',\n
+  s>                 \'<tr class="%class%">\\\n
+  s>                 <td colspan="3" style="text-align: center;">%text%</td>\\\n
+  s>                 </tr>\'\n
+  s>         );\n
+  s>     </script>\n
+  s>     \n
+  s>     </div>\n
+  s>     </div>\n
+  s>     \n
+  s>     \n
+  s>     \n
+  s>     </body>\n
+  s>     </html>\n
+  s>     \n
+  s>     \r\n
+  s>     0\r\n
+  s>     \r\n
+
+  $ hg --verbose debugwireproto http://$LOCALIP:$HGPORT/redirector << EOF
+  > command heads
+  > EOF
+  s>     GET /redirector?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 301 Redirect\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Location: http://$LOCALIP:$HGPORT/redirected\r\n (glob)
+  s>     Content-Type: text/plain\r\n
+  s>     Content-Length: 10\r\n
+  s>     \r\n
+  s>     redirected
+  s>     GET /redirected HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     ETag: W/"*"\r\n (glob)
+  s>     Content-Type: text/html; charset=ascii\r\n
+  s>     Transfer-Encoding: chunked\r\n
+  s>     \r\n
+  real URL is http://$LOCALIP:$HGPORT/redirected (glob)
+  s>     414\r\n
+  s>     <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">\n
+  s>     <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en-US">\n
+  s>     <head>\n
+  s>     <link rel="icon" href="/redirected/static/hgicon.png" type="image/png" />\n
+  s>     <meta name="robots" content="index, nofollow" />\n
+  s>     <link rel="stylesheet" href="/redirected/static/style-paper.css" type="text/css" />\n
+  s>     <script type="text/javascript" src="/redirected/static/mercurial.js"></script>\n
+  s>     \n
+  s>     <title>redirected: log</title>\n
+  s>     <link rel="alternate" type="application/atom+xml"\n
+  s>        href="/redirected/atom-log" title="Atom feed for redirected" />\n
+  s>     <link rel="alternate" type="application/rss+xml"\n
+  s>        href="/redirected/rss-log" title="RSS feed for redirected" />\n
+  s>     </head>\n
+  s>     <body>\n
+  s>     \n
+  s>     <div class="container">\n
+  s>     <div class="menu">\n
+  s>     <div class="logo">\n
+  s>     <a href="https://mercurial-scm.org/">\n
+  s>     <img src="/redirected/static/hglogo.png" alt="mercurial" /></a>\n
+  s>     </div>\n
+  s>     <ul>\n
+  s>     <li class="active">log</li>\n
+  s>     <li><a href="/redirected/graph/tip">graph</a></li>\n
+  s>     <li><a href="/redirected/tags">tags</a
+  s>     GET /redirected?cmd=capabilities HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-0.1\r\n
+  s>     Content-Length: 453\r\n
+  s>     \r\n
+  real URL is http://$LOCALIP:$HGPORT/redirected (glob)
+  s>     batch branchmap $USUAL_BUNDLE2_CAPS_SERVER$ changegroupsubset compression=$BUNDLE2_COMPRESSIONS$ getbundle httpheader=1024 httpmediatype=0.1rx,0.1tx,0.2tx known lookup pushkey streamreqs=generaldelta,revlogv1 unbundle=HG10GZ,HG10BZ,HG10UN unbundlehash
+  sending heads command
+  s>     GET /redirected?cmd=heads HTTP/1.1\r\n
+  s>     Accept-Encoding: identity\r\n
+  s>     vary: X-HgProto-1\r\n
+  s>     x-hgproto-1: 0.1 0.2 comp=$USUAL_COMPRESSIONS$ partial-pull\r\n
+  s>     accept: application/mercurial-0.1\r\n
+  s>     host: $LOCALIP:$HGPORT\r\n (glob)
+  s>     user-agent: Mercurial debugwireproto\r\n
+  s>     \r\n
+  s> makefile('rb', None)
+  s>     HTTP/1.1 200 Script output follows\r\n
+  s>     Server: testing stub value\r\n
+  s>     Date: $HTTP_DATE$\r\n
+  s>     Content-Type: application/mercurial-0.1\r\n
+  s>     Content-Length: 41\r\n
+  s>     \r\n
+  s>     96ee1d7354c4ad7372047672c36a1f561e3a6a4c\n
+  response: [b'\x96\xee\x1dsT\xc4\xadsr\x04vr\xc3j\x1fV\x1e:jL']