bundle2.bundlepart: make mandatory part flag explicit in API

This makes all bundle2 parts mandatory unless they are expressly made advisory
via the keyword parameter or the bundlepart.mandatory property.

mercurial/bundle2.py

@@ -1,1124 +1,1131 b''
 # bundle2.py - generic container format to transmit arbitrary data.
 #
 # Copyright 2013 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 """Handling of the new bundle2 format
 
 The goal of bundle2 is to act as an atomically packet to transmit a set of
 payloads in an application agnostic way. It consist in a sequence of "parts"
 that will be handed to and processed by the application layer.
 
 
 General format architecture
 ===========================
 
 The format is architectured as follow
 
  - magic string
  - stream level parameters
  - payload parts (any number)
  - end of stream marker.
 
 the Binary format
 ============================
 
 All numbers are unsigned and big-endian.
 
 stream level parameters
 ------------------------
 
 Binary format is as follow
 
 :params size: int32
 
   The total number of Bytes used by the parameters
 
 :params value: arbitrary number of Bytes
 
   A blob of `params size` containing the serialized version of all stream level
   parameters.
 
   The blob contains a space separated list of parameters. Parameters with value
   are stored in the form `<name>=<value>`. Both name and value are urlquoted.
 
   Empty name are obviously forbidden.
 
   Name MUST start with a letter. If this first letter is lower case, the
   parameter is advisory and can be safely ignored. However when the first
   letter is capital, the parameter is mandatory and the bundling process MUST
   stop if he is not able to proceed it.
 
   Stream parameters use a simple textual format for two main reasons:
 
   - Stream level parameters should remain simple and we want to discourage any
     crazy usage.
   - Textual data allow easy human inspection of a bundle2 header in case of
     troubles.
 
   Any Applicative level options MUST go into a bundle2 part instead.
 
 Payload part
 ------------------------
 
 Binary format is as follow
 
 :header size: int32
 
   The total number of Bytes used by the part headers. When the header is empty
   (size = 0) this is interpreted as the end of stream marker.
 
 :header:
 
     The header defines how to interpret the part. It contains two piece of
     data: the part type, and the part parameters.
 
     The part type is used to route an application level handler, that can
     interpret payload.
 
     Part parameters are passed to the application level handler.  They are
     meant to convey information that will help the application level object to
     interpret the part payload.
 
     The binary format of the header is has follow
 
     :typesize: (one byte)
 
     :parttype: alphanumerical part name
 
     :partid: A 32bits integer (unique in the bundle) that can be used to refer
              to this part.
 
     :parameters:
 
         Part's parameter may have arbitrary content, the binary structure is::
 
             <mandatory-count><advisory-count><param-sizes><param-data>
 
         :mandatory-count: 1 byte, number of mandatory parameters
 
         :advisory-count:  1 byte, number of advisory parameters
 
         :param-sizes:
 
             N couple of bytes, where N is the total number of parameters. Each
             couple contains (<size-of-key>, <size-of-value) for one parameter.
 
         :param-data:
 
             A blob of bytes from which each parameter key and value can be
             retrieved using the list of size couples stored in the previous
             field.
 
             Mandatory parameters comes first, then the advisory ones.
 
             Each parameter's key MUST be unique within the part.
 
 :payload:
 
     payload is a series of `<chunksize><chunkdata>`.
 
     `chunksize` is an int32, `chunkdata` are plain bytes (as much as
     `chunksize` says)` The payload part is concluded by a zero size chunk.
 
     The current implementation always produces either zero or one chunk.
     This is an implementation limitation that will ultimately be lifted.
 
     `chunksize` can be negative to trigger special case processing. No such
     processing is in place yet.
 
 Bundle processing
 ============================
 
 Each part is processed in order using a "part handler". Handler are registered
 for a certain part type.
 
 The matching of a part to its handler is case insensitive. The case of the
 part type is used to know if a part is mandatory or advisory. If the Part type
 contains any uppercase char it is considered mandatory. When no handler is
 known for a Mandatory part, the process is aborted and an exception is raised.
 If the part is advisory and no handler is known, the part is ignored. When the
 process is aborted, the full bundle is still read from the stream to keep the
 channel usable. But none of the part read from an abort are processed. In the
 future, dropping the stream may become an option for channel we do not care to
 preserve.
 """
 
 import sys
 import util
 import struct
 import urllib
 import string
 import obsolete
 import pushkey
 import url
 
 import changegroup, error
 from i18n import _
 
 _pack = struct.pack
 _unpack = struct.unpack
 
 _magicstring = 'HG2Y'
 
 _fstreamparamsize = '>i'
 _fpartheadersize = '>i'
 _fparttypesize = '>B'
 _fpartid = '>I'
 _fpayloadsize = '>i'
 _fpartparamcount = '>BB'
 
 preferedchunksize = 4096
 
 def _makefpartparamsizes(nbparams):
     """return a struct format to read part parameter sizes
 
     The number parameters is variable so we need to build that format
     dynamically.
     """
     return '>'+('BB'*nbparams)
 
 parthandlermapping = {}
 
 def parthandler(parttype, params=()):
     """decorator that register a function as a bundle2 part handler
 
     eg::
 
         @parthandler('myparttype', ('mandatory', 'param', 'handled'))
         def myparttypehandler(...):
             '''process a part of type "my part".'''
             ...
     """
     def _decorator(func):
         lparttype = parttype.lower() # enforce lower case matching.
         assert lparttype not in parthandlermapping
         parthandlermapping[lparttype] = func
         func.params = frozenset(params)
         return func
     return _decorator
 
 class unbundlerecords(object):
     """keep record of what happens during and unbundle
 
     New records are added using `records.add('cat', obj)`. Where 'cat' is a
     category of record and obj is an arbitrary object.
 
     `records['cat']` will return all entries of this category 'cat'.
 
     Iterating on the object itself will yield `('category', obj)` tuples
     for all entries.
 
     All iterations happens in chronological order.
     """
 
     def __init__(self):
         self._categories = {}
         self._sequences = []
         self._replies = {}
 
     def add(self, category, entry, inreplyto=None):
         """add a new record of a given category.
 
         The entry can then be retrieved in the list returned by
         self['category']."""
         self._categories.setdefault(category, []).append(entry)
         self._sequences.append((category, entry))
         if inreplyto is not None:
             self.getreplies(inreplyto).add(category, entry)
 
     def getreplies(self, partid):
         """get the records that are replies to a specific part"""
         return self._replies.setdefault(partid, unbundlerecords())
 
     def __getitem__(self, cat):
         return tuple(self._categories.get(cat, ()))
 
     def __iter__(self):
         return iter(self._sequences)
 
     def __len__(self):
         return len(self._sequences)
 
     def __nonzero__(self):
         return bool(self._sequences)
 
 class bundleoperation(object):
     """an object that represents a single bundling process
 
     Its purpose is to carry unbundle-related objects and states.
 
     A new object should be created at the beginning of each bundle processing.
     The object is to be returned by the processing function.
 
     The object has very little content now it will ultimately contain:
     * an access to the repo the bundle is applied to,
     * a ui object,
     * a way to retrieve a transaction to add changes to the repo,
     * a way to record the result of processing each part,
     * a way to construct a bundle response when applicable.
     """
 
     def __init__(self, repo, transactiongetter):
         self.repo = repo
         self.ui = repo.ui
         self.records = unbundlerecords()
         self.gettransaction = transactiongetter
         self.reply = None
 
 class TransactionUnavailable(RuntimeError):
     pass
 
 def _notransaction():
     """default method to get a transaction while processing a bundle
 
     Raise an exception to highlight the fact that no transaction was expected
     to be created"""
     raise TransactionUnavailable()
 
 def processbundle(repo, unbundler, transactiongetter=None):
     """This function process a bundle, apply effect to/from a repo
 
     It iterates over each part then searches for and uses the proper handling
     code to process the part. Parts are processed in order.
 
     This is very early version of this function that will be strongly reworked
     before final usage.
 
     Unknown Mandatory part will abort the process.
     """
     if transactiongetter is None:
         transactiongetter = _notransaction
     op = bundleoperation(repo, transactiongetter)
     # todo:
     # - replace this is a init function soon.
     # - exception catching
     unbundler.params
     iterparts = unbundler.iterparts()
     part = None
     try:
         for part in iterparts:
             _processpart(op, part)
     except Exception, exc:
         for part in iterparts:
             # consume the bundle content
             part.read()
         # Small hack to let caller code distinguish exceptions from bundle2
         # processing from processing the old format. This is mostly
         # needed to handle different return codes to unbundle according to the
         # type of bundle. We should probably clean up or drop this return code
         # craziness in a future version.
         exc.duringunbundle2 = True
         raise
     return op
 
 def _processpart(op, part):
     """process a single part from a bundle
 
     The part is guaranteed to have been fully consumed when the function exits
     (even if an exception is raised)."""
     try:
         try:
             handler = parthandlermapping.get(part.type)
             if handler is None:
                 raise error.UnsupportedPartError(parttype=part.type)
             op.ui.debug('found a handler for part %r\n' % part.type)
             unknownparams = part.mandatorykeys - handler.params
             if unknownparams:
                 unknownparams = list(unknownparams)
                 unknownparams.sort()
                 raise error.UnsupportedPartError(parttype=part.type,
                                                params=unknownparams)
         except error.UnsupportedPartError, exc:
             if part.mandatory: # mandatory parts
                 raise
             op.ui.debug('ignoring unsupported advisory part %s\n' % exc)
             return # skip to part processing
 
         # handler is called outside the above try block so that we don't
         # risk catching KeyErrors from anything other than the
         # parthandlermapping lookup (any KeyError raised by handler()
         # itself represents a defect of a different variety).
         output = None
         if op.reply is not None:
             op.ui.pushbuffer(error=True)
             output = ''
         try:
             handler(op, part)
         finally:
             if output is not None:
                 output = op.ui.popbuffer()
         if output:
-            outpart = op.reply.newpart('b2x:output', data=output)
+            outpart = op.reply.newpart('b2x:output', data=output,
+                                       mandatory=False)
             outpart.addparam('in-reply-to', str(part.id), mandatory=False)
     finally:
         # consume the part content to not corrupt the stream.
         part.read()
 
 
 def decodecaps(blob):
     """decode a bundle2 caps bytes blob into a dictionary
 
     The blob is a list of capabilities (one per line)
     Capabilities may have values using a line of the form::
 
         capability=value1,value2,value3
 
     The values are always a list."""
     caps = {}
     for line in blob.splitlines():
         if not line:
             continue
         if '=' not in line:
             key, vals = line, ()
         else:
             key, vals = line.split('=', 1)
             vals = vals.split(',')
         key = urllib.unquote(key)
         vals = [urllib.unquote(v) for v in vals]
         caps[key] = vals
     return caps
 
 def encodecaps(caps):
     """encode a bundle2 caps dictionary into a bytes blob"""
     chunks = []
     for ca in sorted(caps):
         vals = caps[ca]
         ca = urllib.quote(ca)
         vals = [urllib.quote(v) for v in vals]
         if vals:
             ca = "%s=%s" % (ca, ','.join(vals))
         chunks.append(ca)
     return '\n'.join(chunks)
 
 class bundle20(object):
     """represent an outgoing bundle2 container
 
     Use the `addparam` method to add stream level parameter. and `newpart` to
     populate it. Then call `getchunks` to retrieve all the binary chunks of
     data that compose the bundle2 container."""
 
     def __init__(self, ui, capabilities=()):
         self.ui = ui
         self._params = []
         self._parts = []
         self.capabilities = dict(capabilities)
 
     @property
     def nbparts(self):
         """total number of parts added to the bundler"""
         return len(self._parts)
 
     # methods used to defines the bundle2 content
     def addparam(self, name, value=None):
         """add a stream level parameter"""
         if not name:
             raise ValueError('empty parameter name')
         if name[0] not in string.letters:
             raise ValueError('non letter first character: %r' % name)
         self._params.append((name, value))
 
     def addpart(self, part):
         """add a new part to the bundle2 container
 
         Parts contains the actual applicative payload."""
         assert part.id is None
         part.id = len(self._parts) # very cheap counter
         self._parts.append(part)
 
     def newpart(self, typeid, *args, **kwargs):
         """create a new part and add it to the containers
 
         As the part is directly added to the containers. For now, this means
         that any failure to properly initialize the part after calling
         ``newpart`` should result in a failure of the whole bundling process.
 
         You can still fall back to manually create and add if you need better
         control."""
         part = bundlepart(typeid, *args, **kwargs)
         self.addpart(part)
         return part
 
     # methods used to generate the bundle2 stream
     def getchunks(self):
         self.ui.debug('start emission of %s stream\n' % _magicstring)
         yield _magicstring
         param = self._paramchunk()
         self.ui.debug('bundle parameter: %s\n' % param)
         yield _pack(_fstreamparamsize, len(param))
         if param:
             yield param
 
         self.ui.debug('start of parts\n')
         for part in self._parts:
             self.ui.debug('bundle part: "%s"\n' % part.type)
             for chunk in part.getchunks():
                 yield chunk
         self.ui.debug('end of bundle\n')
         yield _pack(_fpartheadersize, 0)
 
     def _paramchunk(self):
         """return a encoded version of all stream parameters"""
         blocks = []
         for par, value in self._params:
             par = urllib.quote(par)
             if value is not None:
                 value = urllib.quote(value)
                 par = '%s=%s' % (par, value)
             blocks.append(par)
         return ' '.join(blocks)
 
 class unpackermixin(object):
     """A mixin to extract bytes and struct data from a stream"""
 
     def __init__(self, fp):
         self._fp = fp
 
     def _unpack(self, format):
         """unpack this struct format from the stream"""
         data = self._readexact(struct.calcsize(format))
         return _unpack(format, data)
 
     def _readexact(self, size):
         """read exactly <size> bytes from the stream"""
         return changegroup.readexactly(self._fp, size)
 
 
 class unbundle20(unpackermixin):
     """interpret a bundle2 stream
 
     This class is fed with a binary stream and yields parts through its
     `iterparts` methods."""
 
     def __init__(self, ui, fp, header=None):
         """If header is specified, we do not read it out of the stream."""
         self.ui = ui
         super(unbundle20, self).__init__(fp)
         if header is None:
             header = self._readexact(4)
             magic, version = header[0:2], header[2:4]
             if magic != 'HG':
                 raise util.Abort(_('not a Mercurial bundle'))
             if version != '2Y':
                 raise util.Abort(_('unknown bundle version %s') % version)
         self.ui.debug('start processing of %s stream\n' % header)
 
     @util.propertycache
     def params(self):
         """dictionary of stream level parameters"""
         self.ui.debug('reading bundle2 stream parameters\n')
         params = {}
         paramssize = self._unpack(_fstreamparamsize)[0]
         if paramssize < 0:
             raise error.BundleValueError('negative bundle param size: %i'
                                          % paramssize)
         if paramssize:
             for p in self._readexact(paramssize).split(' '):
                 p = p.split('=', 1)
                 p = [urllib.unquote(i) for i in p]
                 if len(p) < 2:
                     p.append(None)
                 self._processparam(*p)
                 params[p[0]] = p[1]
         return params
 
     def _processparam(self, name, value):
         """process a parameter, applying its effect if needed
 
         Parameter starting with a lower case letter are advisory and will be
         ignored when unknown.  Those starting with an upper case letter are
         mandatory and will this function will raise a KeyError when unknown.
 
         Note: no option are currently supported. Any input will be either
               ignored or failing.
         """
         if not name:
             raise ValueError('empty parameter name')
         if name[0] not in string.letters:
             raise ValueError('non letter first character: %r' % name)
         # Some logic will be later added here to try to process the option for
         # a dict of known parameter.
         if name[0].islower():
             self.ui.debug("ignoring unknown parameter %r\n" % name)
         else:
             raise error.UnsupportedPartError(params=(name,))
 
 
     def iterparts(self):
         """yield all parts contained in the stream"""
         # make sure param have been loaded
         self.params
         self.ui.debug('start extraction of bundle2 parts\n')
         headerblock = self._readpartheader()
         while headerblock is not None:
             part = unbundlepart(self.ui, headerblock, self._fp)
             yield part
             headerblock = self._readpartheader()
         self.ui.debug('end of bundle2 stream\n')
 
     def _readpartheader(self):
         """reads a part header size and return the bytes blob
 
         returns None if empty"""
         headersize = self._unpack(_fpartheadersize)[0]
         if headersize < 0:
             raise error.BundleValueError('negative part header size: %i'
                                          % headersize)
         self.ui.debug('part header size: %i\n' % headersize)
         if headersize:
             return self._readexact(headersize)
         return None
 
 
 class bundlepart(object):
     """A bundle2 part contains application level payload
 
     The part `type` is used to route the part to the application level
     handler.
 
     The part payload is contained in ``part.data``. It could be raw bytes or a
     generator of byte chunks.
 
     You can add parameters to the part using the ``addparam`` method.
     Parameters can be either mandatory (default) or advisory. Remote side
     should be able to safely ignore the advisory ones.
 
     Both data and parameters cannot be modified after the generation has begun.
     """
 
     def __init__(self, parttype, mandatoryparams=(), advisoryparams=(),
-                 data=''):
+                 data='', mandatory=True):
         self.id = None
         self.type = parttype
         self._data = data
         self._mandatoryparams = list(mandatoryparams)
         self._advisoryparams = list(advisoryparams)
         # checking for duplicated entries
         self._seenparams = set()
         for pname, __ in self._mandatoryparams + self._advisoryparams:
             if pname in self._seenparams:
                 raise RuntimeError('duplicated params: %s' % pname)
             self._seenparams.add(pname)
         # status of the part's generation:
         # - None: not started,
         # - False: currently generated,
         # - True: generation done.
         self._generated = None
+        self.mandatory = mandatory
 
     # methods used to defines the part content
     def __setdata(self, data):
         if self._generated is not None:
             raise error.ReadOnlyPartError('part is being generated')
         self._data = data
     def __getdata(self):
         return self._data
     data = property(__getdata, __setdata)
 
     @property
     def mandatoryparams(self):
         # make it an immutable tuple to force people through ``addparam``
         return tuple(self._mandatoryparams)
 
     @property
     def advisoryparams(self):
         # make it an immutable tuple to force people through ``addparam``
         return tuple(self._advisoryparams)
 
     def addparam(self, name, value='', mandatory=True):
         if self._generated is not None:
             raise error.ReadOnlyPartError('part is being generated')
         if name in self._seenparams:
             raise ValueError('duplicated params: %s' % name)
         self._seenparams.add(name)
         params = self._advisoryparams
         if mandatory:
             params = self._mandatoryparams
         params.append((name, value))
 
     # methods used to generates the bundle2 stream
     def getchunks(self):
         if self._generated is not None:
             raise RuntimeError('part can only be consumed once')
         self._generated = False
         #### header
+        if self.mandatory:
+            parttype = self.type.upper()
+        else:
+            parttype = self.type.lower()
         ## parttype
-        header = [_pack(_fparttypesize, len(self.type)),
-                  self.type, _pack(_fpartid, self.id),
+        header = [_pack(_fparttypesize, len(parttype)),
+                  parttype, _pack(_fpartid, self.id),
                  ]
         ## parameters
         # count
         manpar = self.mandatoryparams
         advpar = self.advisoryparams
         header.append(_pack(_fpartparamcount, len(manpar), len(advpar)))
         # size
         parsizes = []
         for key, value in manpar:
             parsizes.append(len(key))
             parsizes.append(len(value))
         for key, value in advpar:
             parsizes.append(len(key))
             parsizes.append(len(value))
         paramsizes = _pack(_makefpartparamsizes(len(parsizes) / 2), *parsizes)
         header.append(paramsizes)
         # key, value
         for key, value in manpar:
             header.append(key)
             header.append(value)
         for key, value in advpar:
             header.append(key)
             header.append(value)
         ## finalize header
         headerchunk = ''.join(header)
         yield _pack(_fpartheadersize, len(headerchunk))
         yield headerchunk
         ## payload
         try:
             for chunk in self._payloadchunks():
                 yield _pack(_fpayloadsize, len(chunk))
                 yield chunk
         except Exception, exc:
             # backup exception data for later
             exc_info = sys.exc_info()
             msg = 'unexpected error: %s' % exc
-            interpart = bundlepart('b2x:error:abort', [('message', msg)])
+            interpart = bundlepart('b2x:error:abort', [('message', msg)],
+                                   mandatory=False)
             interpart.id = 0
             yield _pack(_fpayloadsize, -1)
             for chunk in interpart.getchunks():
                 yield chunk
             # abort current part payload
             yield _pack(_fpayloadsize, 0)
             raise exc_info[0], exc_info[1], exc_info[2]
         # end of payload
         yield _pack(_fpayloadsize, 0)
         self._generated = True
 
     def _payloadchunks(self):
         """yield chunks of a the part payload
 
         Exists to handle the different methods to provide data to a part."""
         # we only support fixed size data now.
         # This will be improved in the future.
         if util.safehasattr(self.data, 'next'):
             buff = util.chunkbuffer(self.data)
             chunk = buff.read(preferedchunksize)
             while chunk:
                 yield chunk
                 chunk = buff.read(preferedchunksize)
         elif len(self.data):
             yield self.data
 
 
 flaginterrupt = -1
 
 class interrupthandler(unpackermixin):
     """read one part and process it with restricted capability
 
     This allows to transmit exception raised on the producer size during part
     iteration while the consumer is reading a part.
 
     Part processed in this manner only have access to a ui object,"""
 
     def __init__(self, ui, fp):
         super(interrupthandler, self).__init__(fp)
         self.ui = ui
 
     def _readpartheader(self):
         """reads a part header size and return the bytes blob
 
         returns None if empty"""
         headersize = self._unpack(_fpartheadersize)[0]
         if headersize < 0:
             raise error.BundleValueError('negative part header size: %i'
                                          % headersize)
         self.ui.debug('part header size: %i\n' % headersize)
         if headersize:
             return self._readexact(headersize)
         return None
 
     def __call__(self):
         self.ui.debug('bundle2 stream interruption, looking for a part.\n')
         headerblock = self._readpartheader()
         if headerblock is None:
             self.ui.debug('no part found during interruption.\n')
             return
         part = unbundlepart(self.ui, headerblock, self._fp)
         op = interruptoperation(self.ui)
         _processpart(op, part)
 
 class interruptoperation(object):
     """A limited operation to be use by part handler during interruption
 
     It only have access to an ui object.
     """
 
     def __init__(self, ui):
         self.ui = ui
         self.reply = None
 
     @property
     def repo(self):
         raise RuntimeError('no repo access from stream interruption')
 
     def gettransaction(self):
         raise TransactionUnavailable('no repo access from stream interruption')
 
 class unbundlepart(unpackermixin):
     """a bundle part read from a bundle"""
 
     def __init__(self, ui, header, fp):
         super(unbundlepart, self).__init__(fp)
         self.ui = ui
         # unbundle state attr
         self._headerdata = header
         self._headeroffset = 0
         self._initialized = False
         self.consumed = False
         # part data
         self.id = None
         self.type = None
         self.mandatoryparams = None
         self.advisoryparams = None
         self.params = None
         self.mandatorykeys = ()
         self._payloadstream = None
         self._readheader()
         self._mandatory = None
 
     def _fromheader(self, size):
         """return the next <size> byte from the header"""
         offset = self._headeroffset
         data = self._headerdata[offset:(offset + size)]
         self._headeroffset = offset + size
         return data
 
     def _unpackheader(self, format):
         """read given format from header
 
         This automatically compute the size of the format to read."""
         data = self._fromheader(struct.calcsize(format))
         return _unpack(format, data)
 
     def _initparams(self, mandatoryparams, advisoryparams):
         """internal function to setup all logic related parameters"""
         # make it read only to prevent people touching it by mistake.
         self.mandatoryparams = tuple(mandatoryparams)
         self.advisoryparams  = tuple(advisoryparams)
         # user friendly UI
         self.params = dict(self.mandatoryparams)
         self.params.update(dict(self.advisoryparams))
         self.mandatorykeys = frozenset(p[0] for p in mandatoryparams)
 
     def _readheader(self):
         """read the header and setup the object"""
         typesize = self._unpackheader(_fparttypesize)[0]
         self.type = self._fromheader(typesize)
         self.ui.debug('part type: "%s"\n' % self.type)
         self.id = self._unpackheader(_fpartid)[0]
         self.ui.debug('part id: "%s"\n' % self.id)
         # extract mandatory bit from type
         self.mandatory = (self.type != self.type.lower())
         self.type = self.type.lower()
         ## reading parameters
         # param count
         mancount, advcount = self._unpackheader(_fpartparamcount)
         self.ui.debug('part parameters: %i\n' % (mancount + advcount))
         # param size
         fparamsizes = _makefpartparamsizes(mancount + advcount)
         paramsizes = self._unpackheader(fparamsizes)
         # make it a list of couple again
         paramsizes = zip(paramsizes[::2], paramsizes[1::2])
         # split mandatory from advisory
         mansizes = paramsizes[:mancount]
         advsizes = paramsizes[mancount:]
         # retrieve param value
         manparams = []
         for key, value in mansizes:
             manparams.append((self._fromheader(key), self._fromheader(value)))
         advparams = []
         for key, value in advsizes:
             advparams.append((self._fromheader(key), self._fromheader(value)))
         self._initparams(manparams, advparams)
         ## part payload
         def payloadchunks():
             payloadsize = self._unpack(_fpayloadsize)[0]
             self.ui.debug('payload chunk size: %i\n' % payloadsize)
             while payloadsize:
                 if payloadsize == flaginterrupt:
                     # interruption detection, the handler will now read a
                     # single part and process it.
                     interrupthandler(self.ui, self._fp)()
                 elif payloadsize < 0:
                     msg = 'negative payload chunk size: %i' %  payloadsize
                     raise error.BundleValueError(msg)
                 else:
                     yield self._readexact(payloadsize)
                 payloadsize = self._unpack(_fpayloadsize)[0]
                 self.ui.debug('payload chunk size: %i\n' % payloadsize)
         self._payloadstream = util.chunkbuffer(payloadchunks())
         # we read the data, tell it
         self._initialized = True
 
     def read(self, size=None):
         """read payload data"""
         if not self._initialized:
             self._readheader()
         if size is None:
             data = self._payloadstream.read()
         else:
             data = self._payloadstream.read(size)
         if size is None or len(data) < size:
             self.consumed = True
         return data
 
 capabilities = {'HG2Y': (),
                 'b2x:listkeys': (),
                 'b2x:pushkey': (),
                 'digests': tuple(sorted(util.DIGESTS.keys())),
                 'b2x:remote-changegroup': ('http', 'https'),
                }
 
 def getrepocaps(repo, allowpushback=False):
     """return the bundle2 capabilities for a given repo
 
     Exists to allow extensions (like evolution) to mutate the capabilities.
     """
     caps = capabilities.copy()
     caps['b2x:changegroup'] = tuple(sorted(changegroup.packermap.keys()))
     if obsolete.isenabled(repo, obsolete.exchangeopt):
         supportedformat = tuple('V%i' % v for v in obsolete.formats)
         caps['b2x:obsmarkers'] = supportedformat
     if allowpushback:
         caps['b2x:pushback'] = ()
     return caps
 
 def bundle2caps(remote):
     """return the bundle capabilities of a peer as dict"""
     raw = remote.capable('bundle2-exp')
     if not raw and raw != '':
         return {}
     capsblob = urllib.unquote(remote.capable('bundle2-exp'))
     return decodecaps(capsblob)
 
 def obsmarkersversion(caps):
     """extract the list of supported obsmarkers versions from a bundle2caps dict
     """
     obscaps = caps.get('b2x:obsmarkers', ())
     return [int(c[1:]) for c in obscaps if c.startswith('V')]
 
 @parthandler('b2x:changegroup', ('version',))
 def handlechangegroup(op, inpart):
     """apply a changegroup part on the repo
 
     This is a very early implementation that will massive rework before being
     inflicted to any end-user.
     """
     # Make sure we trigger a transaction creation
     #
     # The addchangegroup function will get a transaction object by itself, but
     # we need to make sure we trigger the creation of a transaction object used
     # for the whole processing scope.
     op.gettransaction()
     unpackerversion = inpart.params.get('version', '01')
     # We should raise an appropriate exception here
     unpacker = changegroup.packermap[unpackerversion][1]
     cg = unpacker(inpart, 'UN')
     # the source and url passed here are overwritten by the one contained in
     # the transaction.hookargs argument. So 'bundle2' is a placeholder
     ret = changegroup.addchangegroup(op.repo, cg, 'bundle2', 'bundle2')
     op.records.add('changegroup', {'return': ret})
     if op.reply is not None:
         # This is definitely not the final form of this
         # return. But one need to start somewhere.
-        part = op.reply.newpart('b2x:reply:changegroup')
+        part = op.reply.newpart('b2x:reply:changegroup', mandatory=False)
         part.addparam('in-reply-to', str(inpart.id), mandatory=False)
         part.addparam('return', '%i' % ret, mandatory=False)
     assert not inpart.read()
 
 _remotechangegroupparams = tuple(['url', 'size', 'digests'] +
     ['digest:%s' % k for k in util.DIGESTS.keys()])
 @parthandler('b2x:remote-changegroup', _remotechangegroupparams)
 def handleremotechangegroup(op, inpart):
     """apply a bundle10 on the repo, given an url and validation information
 
     All the information about the remote bundle to import are given as
     parameters. The parameters include:
       - url: the url to the bundle10.
       - size: the bundle10 file size. It is used to validate what was
         retrieved by the client matches the server knowledge about the bundle.
       - digests: a space separated list of the digest types provided as
         parameters.
       - digest:<digest-type>: the hexadecimal representation of the digest with
         that name. Like the size, it is used to validate what was retrieved by
         the client matches what the server knows about the bundle.
 
     When multiple digest types are given, all of them are checked.
     """
     try:
         raw_url = inpart.params['url']
     except KeyError:
         raise util.Abort(_('remote-changegroup: missing "%s" param') % 'url')
     parsed_url = util.url(raw_url)
     if parsed_url.scheme not in capabilities['b2x:remote-changegroup']:
         raise util.Abort(_('remote-changegroup does not support %s urls') %
             parsed_url.scheme)
 
     try:
         size = int(inpart.params['size'])
     except ValueError:
         raise util.Abort(_('remote-changegroup: invalid value for param "%s"')
             % 'size')
     except KeyError:
         raise util.Abort(_('remote-changegroup: missing "%s" param') % 'size')
 
     digests = {}
     for typ in inpart.params.get('digests', '').split():
         param = 'digest:%s' % typ
         try:
             value = inpart.params[param]
         except KeyError:
             raise util.Abort(_('remote-changegroup: missing "%s" param') %
                 param)
         digests[typ] = value
 
     real_part = util.digestchecker(url.open(op.ui, raw_url), size, digests)
 
     # Make sure we trigger a transaction creation
     #
     # The addchangegroup function will get a transaction object by itself, but
     # we need to make sure we trigger the creation of a transaction object used
     # for the whole processing scope.
     op.gettransaction()
     import exchange
     cg = exchange.readbundle(op.repo.ui, real_part, raw_url)
     if not isinstance(cg, changegroup.cg1unpacker):
         raise util.Abort(_('%s: not a bundle version 1.0') %
             util.hidepassword(raw_url))
     ret = changegroup.addchangegroup(op.repo, cg, 'bundle2', 'bundle2')
     op.records.add('changegroup', {'return': ret})
     if op.reply is not None:
         # This is definitely not the final form of this
         # return. But one need to start somewhere.
         part = op.reply.newpart('b2x:reply:changegroup')
         part.addparam('in-reply-to', str(inpart.id), mandatory=False)
         part.addparam('return', '%i' % ret, mandatory=False)
     try:
         real_part.validate()
     except util.Abort, e:
         raise util.Abort(_('bundle at %s is corrupted:\n%s') %
             (util.hidepassword(raw_url), str(e)))
     assert not inpart.read()
 
 @parthandler('b2x:reply:changegroup', ('return', 'in-reply-to'))
 def handlereplychangegroup(op, inpart):
     ret = int(inpart.params['return'])
     replyto = int(inpart.params['in-reply-to'])
     op.records.add('changegroup', {'return': ret}, replyto)
 
 @parthandler('b2x:check:heads')
 def handlecheckheads(op, inpart):
     """check that head of the repo did not change
 
     This is used to detect a push race when using unbundle.
     This replaces the "heads" argument of unbundle."""
     h = inpart.read(20)
     heads = []
     while len(h) == 20:
         heads.append(h)
         h = inpart.read(20)
     assert not h
     if heads != op.repo.heads():
         raise error.PushRaced('repository changed while pushing - '
                               'please try again')
 
 @parthandler('b2x:output')
 def handleoutput(op, inpart):
     """forward output captured on the server to the client"""
     for line in inpart.read().splitlines():
         op.ui.write(('remote: %s\n' % line))
 
 @parthandler('b2x:replycaps')
 def handlereplycaps(op, inpart):
     """Notify that a reply bundle should be created
 
     The payload contains the capabilities information for the reply"""
     caps = decodecaps(inpart.read())
     if op.reply is None:
         op.reply = bundle20(op.ui, caps)
 
 @parthandler('b2x:error:abort', ('message', 'hint'))
 def handlereplycaps(op, inpart):
     """Used to transmit abort error over the wire"""
     raise util.Abort(inpart.params['message'], hint=inpart.params.get('hint'))
 
 @parthandler('b2x:error:unsupportedcontent', ('parttype', 'params'))
 def handlereplycaps(op, inpart):
     """Used to transmit unknown content error over the wire"""
     kwargs = {}
     parttype = inpart.params.get('parttype')
     if parttype is not None:
         kwargs['parttype'] = parttype
     params = inpart.params.get('params')
     if params is not None:
         kwargs['params'] = params.split('\0')
 
     raise error.UnsupportedPartError(**kwargs)
 
 @parthandler('b2x:error:pushraced', ('message',))
 def handlereplycaps(op, inpart):
     """Used to transmit push race error over the wire"""
     raise error.ResponseError(_('push failed:'), inpart.params['message'])
 
 @parthandler('b2x:listkeys', ('namespace',))
 def handlelistkeys(op, inpart):
     """retrieve pushkey namespace content stored in a bundle2"""
     namespace = inpart.params['namespace']
     r = pushkey.decodekeys(inpart.read())
     op.records.add('listkeys', (namespace, r))
 
 @parthandler('b2x:pushkey', ('namespace', 'key', 'old', 'new'))
 def handlepushkey(op, inpart):
     """process a pushkey request"""
     dec = pushkey.decode
     namespace = dec(inpart.params['namespace'])
     key = dec(inpart.params['key'])
     old = dec(inpart.params['old'])
     new = dec(inpart.params['new'])
     ret = op.repo.pushkey(namespace, key, old, new)
     record = {'namespace': namespace,
               'key': key,
               'old': old,
               'new': new}
     op.records.add('pushkey', record)
     if op.reply is not None:
         rpart = op.reply.newpart('b2x:reply:pushkey')
         rpart.addparam('in-reply-to', str(inpart.id), mandatory=False)
         rpart.addparam('return', '%i' % ret, mandatory=False)
 
 @parthandler('b2x:reply:pushkey', ('return', 'in-reply-to'))
 def handlepushkeyreply(op, inpart):
     """retrieve the result of a pushkey request"""
     ret = int(inpart.params['return'])
     partid = int(inpart.params['in-reply-to'])
     op.records.add('pushkey', {'return': ret}, partid)
 
 @parthandler('b2x:obsmarkers')
 def handleobsmarker(op, inpart):
     """add a stream of obsmarkers to the repo"""
     tr = op.gettransaction()
     new = op.repo.obsstore.mergemarkers(tr, inpart.read())
     if new:
         op.repo.ui.status(_('%i new obsolescence markers\n') % new)
     op.records.add('obsmarkers', {'new': new})
     if op.reply is not None:
         rpart = op.reply.newpart('b2x:reply:obsmarkers')
         rpart.addparam('in-reply-to', str(inpart.id), mandatory=False)
         rpart.addparam('new', '%i' % new, mandatory=False)
 
 
 @parthandler('b2x:reply:obsmarkers', ('new', 'in-reply-to'))
 def handlepushkeyreply(op, inpart):
     """retrieve the result of a pushkey request"""
     ret = int(inpart.params['new'])
     partid = int(inpart.params['in-reply-to'])
     op.records.add('obsmarkers', {'new': ret}, partid)

tests/test-bundle2-format.t

@@ -1,799 +1,802 b''
 This test is dedicated to test the bundle2 container format
 
 It test multiple existing parts to test different feature of the container. You
 probably do not need to touch this test unless you change the binary encoding
 of the bundle2 format itself.
 
 Create an extension to test bundle2 API
 
   $ cat > bundle2.py << EOF
   > """A small extension to test bundle2 implementation
   > 
   > Current bundle2 implementation is far too limited to be used in any core
   > code. We still need to be able to test it while it grow up.
   > """
   > 
   > import sys, os
   > from mercurial import cmdutil
   > from mercurial import util
   > from mercurial import bundle2
   > from mercurial import scmutil
   > from mercurial import discovery
   > from mercurial import changegroup
   > from mercurial import error
   > from mercurial import obsolete
   > 
   > 
   > try:
   >     import msvcrt
   >     msvcrt.setmode(sys.stdin.fileno(), os.O_BINARY)
   >     msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
   >     msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
   > except ImportError:
   >     pass
   > 
   > cmdtable = {}
   > command = cmdutil.command(cmdtable)
   > 
   > ELEPHANTSSONG = """Patali Dirapata, Cromda Cromda Ripalo, Pata Pata, Ko Ko Ko
   > Bokoro Dipoulito, Rondi Rondi Pepino, Pata Pata, Ko Ko Ko
   > Emana Karassoli, Loucra Loucra Ponponto, Pata Pata, Ko Ko Ko."""
   > assert len(ELEPHANTSSONG) == 178 # future test say 178 bytes, trust it.
   > 
   > @bundle2.parthandler('test:song')
   > def songhandler(op, part):
   >     """handle a "test:song" bundle2 part, printing the lyrics on stdin"""
   >     op.ui.write('The choir starts singing:\n')
   >     verses = 0
   >     for line in part.read().split('\n'):
   >         op.ui.write('    %s\n' % line)
   >         verses += 1
   >     op.records.add('song', {'verses': verses})
   > 
   > @bundle2.parthandler('test:ping')
   > def pinghandler(op, part):
   >     op.ui.write('received ping request (id %i)\n' % part.id)
   >     if op.reply is not None and 'ping-pong' in op.reply.capabilities:
   >         op.ui.write_err('replying to ping request (id %i)\n' % part.id)
-  >         op.reply.newpart('test:pong', [('in-reply-to', str(part.id))])
+  >         op.reply.newpart('test:pong', [('in-reply-to', str(part.id))],
+  >                          mandatory=False)
   > 
   > @bundle2.parthandler('test:debugreply')
   > def debugreply(op, part):
   >     """print data about the capacity of the bundle reply"""
   >     if op.reply is None:
   >         op.ui.write('debugreply: no reply\n')
   >     else:
   >         op.ui.write('debugreply: capabilities:\n')
   >         for cap in sorted(op.reply.capabilities):
   >             op.ui.write('debugreply:     %r\n' % cap)
   >             for val in op.reply.capabilities[cap]:
   >                 op.ui.write('debugreply:         %r\n' % val)
   > 
   > @command('bundle2',
   >          [('', 'param', [], 'stream level parameter'),
   >           ('', 'unknown', False, 'include an unknown mandatory part in the bundle'),
   >           ('', 'unknownparams', False, 'include an unknown part parameters in the bundle'),
   >           ('', 'parts', False, 'include some arbitrary parts to the bundle'),
   >           ('', 'reply', False, 'produce a reply bundle'),
   >           ('', 'pushrace', False, 'includes a check:head part with unknown nodes'),
   >           ('', 'genraise', False, 'includes a part that raise an exception during generation'),
   >           ('r', 'rev', [], 'includes those changeset in the bundle'),],
   >          '[OUTPUTFILE]')
   > def cmdbundle2(ui, repo, path=None, **opts):
   >     """write a bundle2 container on standard output"""
   >     bundler = bundle2.bundle20(ui)
   >     for p in opts['param']:
   >         p = p.split('=', 1)
   >         try:
   >             bundler.addparam(*p)
   >         except ValueError, exc:
   >             raise util.Abort('%s' % exc)
   > 
   >     if opts['reply']:
   >         capsstring = 'ping-pong\nelephants=babar,celeste\ncity%3D%21=celeste%2Cville'
   >         bundler.newpart('b2x:replycaps', data=capsstring)
   > 
   >     if opts['pushrace']:
   >         # also serve to test the assignement of data outside of init
   >         part = bundler.newpart('b2x:check:heads')
   >         part.data = '01234567890123456789'
   > 
   >     revs = opts['rev']
   >     if 'rev' in opts:
   >         revs = scmutil.revrange(repo, opts['rev'])
   >         if revs:
   >             # very crude version of a changegroup part creation
   >             bundled = repo.revs('%ld::%ld', revs, revs)
   >             headmissing = [c.node() for c in repo.set('heads(%ld)', revs)]
   >             headcommon  = [c.node() for c in repo.set('parents(%ld) - %ld', revs, revs)]
   >             outgoing = discovery.outgoing(repo.changelog, headcommon, headmissing)
   >             cg = changegroup.getlocalchangegroup(repo, 'test:bundle2', outgoing, None)
-  >             bundler.newpart('b2x:changegroup', data=cg.getchunks())
+  >             bundler.newpart('b2x:changegroup', data=cg.getchunks(),
+  >                             mandatory=False)
   > 
   >     if opts['parts']:
-  >        bundler.newpart('test:empty')
+  >        bundler.newpart('test:empty', mandatory=False)
   >        # add a second one to make sure we handle multiple parts
-  >        bundler.newpart('test:empty')
-  >        bundler.newpart('test:song', data=ELEPHANTSSONG)
-  >        bundler.newpart('test:debugreply')
+  >        bundler.newpart('test:empty', mandatory=False)
+  >        bundler.newpart('test:song', data=ELEPHANTSSONG, mandatory=False)
+  >        bundler.newpart('test:debugreply', mandatory=False)
   >        mathpart = bundler.newpart('test:math')
   >        mathpart.addparam('pi', '3.14')
   >        mathpart.addparam('e', '2.72')
   >        mathpart.addparam('cooking', 'raw', mandatory=False)
   >        mathpart.data = '42'
+  >        mathpart.mandatory = False
   >        # advisory known part with unknown mandatory param
-  >        bundler.newpart('test:song', [('randomparam','')])
+  >        bundler.newpart('test:song', [('randomparam','')], mandatory=False)
   >     if opts['unknown']:
   >        bundler.newpart('test:UNKNOWN', data='some random content')
   >     if opts['unknownparams']:
   >        bundler.newpart('test:SONG', [('randomparams', '')])
   >     if opts['parts']:
-  >        bundler.newpart('test:ping')
+  >        bundler.newpart('test:ping', mandatory=False)
   >     if opts['genraise']:
   >        def genraise():
   >            yield 'first line\n'
   >            raise RuntimeError('Someone set up us the bomb!')
-  >        bundler.newpart('b2x:output', data=genraise())
+  >        bundler.newpart('b2x:output', data=genraise(), mandatory=False)
   > 
   >     if path is None:
   >        file = sys.stdout
   >     else:
   >         file = open(path, 'wb')
   > 
   >     try:
   >         for chunk in bundler.getchunks():
   >             file.write(chunk)
   >     except RuntimeError, exc:
   >         raise util.Abort(exc)
   > 
   > @command('unbundle2', [], '')
   > def cmdunbundle2(ui, repo, replypath=None):
   >     """process a bundle2 stream from stdin on the current repo"""
   >     try:
   >         tr = None
   >         lock = repo.lock()
   >         tr = repo.transaction('processbundle')
   >         try:
   >             unbundler = bundle2.unbundle20(ui, sys.stdin)
   >             op = bundle2.processbundle(repo, unbundler, lambda: tr)
   >             tr.close()
   >         except error.BundleValueError, exc:
   >             raise util.Abort('missing support for %s' % exc)
   >         except error.PushRaced, exc:
   >             raise util.Abort('push race: %s' % exc)
   >     finally:
   >         if tr is not None:
   >             tr.release()
   >         lock.release()
   >         remains = sys.stdin.read()
   >         ui.write('%i unread bytes\n' % len(remains))
   >     if op.records['song']:
   >         totalverses = sum(r['verses'] for r in op.records['song'])
   >         ui.write('%i total verses sung\n' % totalverses)
   >     for rec in op.records['changegroup']:
   >         ui.write('addchangegroup return: %i\n' % rec['return'])
   >     if op.reply is not None and replypath is not None:
   >         file = open(replypath, 'wb')
   >         for chunk in op.reply.getchunks():
   >             file.write(chunk)
   > 
   > @command('statbundle2', [], '')
   > def cmdstatbundle2(ui, repo):
   >     """print statistic on the bundle2 container read from stdin"""
   >     unbundler = bundle2.unbundle20(ui, sys.stdin)
   >     try:
   >         params = unbundler.params
   >     except error.BundleValueError, exc:
   >        raise util.Abort('unknown parameters: %s' % exc)
   >     ui.write('options count: %i\n' % len(params))
   >     for key in sorted(params):
   >         ui.write('- %s\n' % key)
   >         value = params[key]
   >         if value is not None:
   >             ui.write('    %s\n' % value)
   >     count = 0
   >     for p in unbundler.iterparts():
   >         count += 1
   >         ui.write('  :%s:\n' % p.type)
   >         ui.write('    mandatory: %i\n' % len(p.mandatoryparams))
   >         ui.write('    advisory: %i\n' % len(p.advisoryparams))
   >         ui.write('    payload: %i bytes\n' % len(p.read()))
   >     ui.write('parts count:   %i\n' % count)
   > EOF
   $ cat >> $HGRCPATH << EOF
   > [extensions]
   > bundle2=$TESTTMP/bundle2.py
   > [experimental]
   > bundle2-exp=True
   > evolution=createmarkers
   > [ui]
   > ssh=python "$TESTDIR/dummyssh"
   > logtemplate={rev}:{node|short} {phase} {author} {bookmarks} {desc|firstline}
   > [web]
   > push_ssl = false
   > allow_push = *
   > [phases]
   > publish=False
   > EOF
 
 The extension requires a repo (currently unused)
 
   $ hg init main
   $ cd main
   $ touch a
   $ hg add a
   $ hg commit -m 'a'
 
 
 Empty bundle
 =================
 
 - no option
 - no parts
 
 Test bundling
 
   $ hg bundle2
   HG2Y\x00\x00\x00\x00\x00\x00\x00\x00 (no-eol) (esc)
 
 Test unbundling
 
   $ hg bundle2 | hg statbundle2
   options count: 0
   parts count:   0
 
 Test old style bundle are detected and refused
 
   $ hg bundle --all ../bundle.hg
   1 changesets found
   $ hg statbundle2 < ../bundle.hg
   abort: unknown bundle version 10
   [255]
 
 Test parameters
 =================
 
 - some options
 - no parts
 
 advisory parameters, no value
 -------------------------------
 
 Simplest possible parameters form
 
 Test generation simple option
 
   $ hg bundle2 --param 'caution'
   HG2Y\x00\x00\x00\x07caution\x00\x00\x00\x00 (no-eol) (esc)
 
 Test unbundling
 
   $ hg bundle2 --param 'caution' | hg statbundle2
   options count: 1
   - caution
   parts count:   0
 
 Test generation multiple option
 
   $ hg bundle2 --param 'caution' --param 'meal'
   HG2Y\x00\x00\x00\x0ccaution meal\x00\x00\x00\x00 (no-eol) (esc)
 
 Test unbundling
 
   $ hg bundle2 --param 'caution' --param 'meal' | hg statbundle2
   options count: 2
   - caution
   - meal
   parts count:   0
 
 advisory parameters, with value
 -------------------------------
 
 Test generation
 
   $ hg bundle2 --param 'caution' --param 'meal=vegan' --param 'elephants'
   HG2Y\x00\x00\x00\x1ccaution meal=vegan elephants\x00\x00\x00\x00 (no-eol) (esc)
 
 Test unbundling
 
   $ hg bundle2 --param 'caution' --param 'meal=vegan' --param 'elephants' | hg statbundle2
   options count: 3
   - caution
   - elephants
   - meal
       vegan
   parts count:   0
 
 parameter with special char in value
 ---------------------------------------------------
 
 Test generation
 
   $ hg bundle2 --param 'e|! 7/=babar%#==tutu' --param simple
   HG2Y\x00\x00\x00)e%7C%21%207/=babar%25%23%3D%3Dtutu simple\x00\x00\x00\x00 (no-eol) (esc)
 
 Test unbundling
 
   $ hg bundle2 --param 'e|! 7/=babar%#==tutu' --param simple | hg statbundle2
   options count: 2
   - e|! 7/
       babar%#==tutu
   - simple
   parts count:   0
 
 Test unknown mandatory option
 ---------------------------------------------------
 
   $ hg bundle2 --param 'Gravity' | hg statbundle2
   abort: unknown parameters: Stream Parameter - Gravity
   [255]
 
 Test debug output
 ---------------------------------------------------
 
 bundling debug
 
   $ hg bundle2 --debug --param 'e|! 7/=babar%#==tutu' --param simple ../out.hg2
   start emission of HG2Y stream
   bundle parameter: e%7C%21%207/=babar%25%23%3D%3Dtutu simple
   start of parts
   end of bundle
 
 file content is ok
 
   $ cat ../out.hg2
   HG2Y\x00\x00\x00)e%7C%21%207/=babar%25%23%3D%3Dtutu simple\x00\x00\x00\x00 (no-eol) (esc)
 
 unbundling debug
 
   $ hg statbundle2 --debug < ../out.hg2
   start processing of HG2Y stream
   reading bundle2 stream parameters
   ignoring unknown parameter 'e|! 7/'
   ignoring unknown parameter 'simple'
   options count: 2
   - e|! 7/
       babar%#==tutu
   - simple
   start extraction of bundle2 parts
   part header size: 0
   end of bundle2 stream
   parts count:   0
 
 
 Test buggy input
 ---------------------------------------------------
 
 empty parameter name
 
   $ hg bundle2 --param '' --quiet
   abort: empty parameter name
   [255]
 
 bad parameter name
 
   $ hg bundle2 --param 42babar
   abort: non letter first character: '42babar'
   [255]
 
 
 Test part
 =================
 
   $ hg bundle2 --parts ../parts.hg2 --debug
   start emission of HG2Y stream
   bundle parameter: 
   start of parts
   bundle part: "test:empty"
   bundle part: "test:empty"
   bundle part: "test:song"
   bundle part: "test:debugreply"
   bundle part: "test:math"
   bundle part: "test:song"
   bundle part: "test:ping"
   end of bundle
 
   $ cat ../parts.hg2
   HG2Y\x00\x00\x00\x00\x00\x00\x00\x11 (esc)
   test:empty\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x11 (esc)
   test:empty\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10	test:song\x00\x00\x00\x02\x00\x00\x00\x00\x00\xb2Patali Dirapata, Cromda Cromda Ripalo, Pata Pata, Ko Ko Ko (esc)
   Bokoro Dipoulito, Rondi Rondi Pepino, Pata Pata, Ko Ko Ko
   Emana Karassoli, Loucra Loucra Ponponto, Pata Pata, Ko Ko Ko.\x00\x00\x00\x00\x00\x00\x00\x16\x0ftest:debugreply\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00+	test:math\x00\x00\x00\x04\x02\x01\x02\x04\x01\x04\x07\x03pi3.14e2.72cookingraw\x00\x00\x00\x0242\x00\x00\x00\x00\x00\x00\x00\x1d	test:song\x00\x00\x00\x05\x01\x00\x0b\x00randomparam\x00\x00\x00\x00\x00\x00\x00\x10	test:ping\x00\x00\x00\x06\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 (no-eol) (esc)
 
 
   $ hg statbundle2 < ../parts.hg2
   options count: 0
     :test:empty:
       mandatory: 0
       advisory: 0
       payload: 0 bytes
     :test:empty:
       mandatory: 0
       advisory: 0
       payload: 0 bytes
     :test:song:
       mandatory: 0
       advisory: 0
       payload: 178 bytes
     :test:debugreply:
       mandatory: 0
       advisory: 0
       payload: 0 bytes
     :test:math:
       mandatory: 2
       advisory: 1
       payload: 2 bytes
     :test:song:
       mandatory: 1
       advisory: 0
       payload: 0 bytes
     :test:ping:
       mandatory: 0
       advisory: 0
       payload: 0 bytes
   parts count:   7
 
   $ hg statbundle2 --debug < ../parts.hg2
   start processing of HG2Y stream
   reading bundle2 stream parameters
   options count: 0
   start extraction of bundle2 parts
   part header size: 17
   part type: "test:empty"
   part id: "0"
   part parameters: 0
     :test:empty:
       mandatory: 0
       advisory: 0
   payload chunk size: 0
       payload: 0 bytes
   part header size: 17
   part type: "test:empty"
   part id: "1"
   part parameters: 0
     :test:empty:
       mandatory: 0
       advisory: 0
   payload chunk size: 0
       payload: 0 bytes
   part header size: 16
   part type: "test:song"
   part id: "2"
   part parameters: 0
     :test:song:
       mandatory: 0
       advisory: 0
   payload chunk size: 178
   payload chunk size: 0
       payload: 178 bytes
   part header size: 22
   part type: "test:debugreply"
   part id: "3"
   part parameters: 0
     :test:debugreply:
       mandatory: 0
       advisory: 0
   payload chunk size: 0
       payload: 0 bytes
   part header size: 43
   part type: "test:math"
   part id: "4"
   part parameters: 3
     :test:math:
       mandatory: 2
       advisory: 1
   payload chunk size: 2
   payload chunk size: 0
       payload: 2 bytes
   part header size: 29
   part type: "test:song"
   part id: "5"
   part parameters: 1
     :test:song:
       mandatory: 1
       advisory: 0
   payload chunk size: 0
       payload: 0 bytes
   part header size: 16
   part type: "test:ping"
   part id: "6"
   part parameters: 0
     :test:ping:
       mandatory: 0
       advisory: 0
   payload chunk size: 0
       payload: 0 bytes
   part header size: 0
   end of bundle2 stream
   parts count:   7
 
 Test actual unbundling of test part
 =======================================
 
 Process the bundle
 
   $ hg unbundle2 --debug < ../parts.hg2
   start processing of HG2Y stream
   reading bundle2 stream parameters
   start extraction of bundle2 parts
   part header size: 17
   part type: "test:empty"
   part id: "0"
   part parameters: 0
   ignoring unsupported advisory part test:empty
   payload chunk size: 0
   part header size: 17
   part type: "test:empty"
   part id: "1"
   part parameters: 0
   ignoring unsupported advisory part test:empty
   payload chunk size: 0
   part header size: 16
   part type: "test:song"
   part id: "2"
   part parameters: 0
   found a handler for part 'test:song'
   The choir starts singing:
   payload chunk size: 178
   payload chunk size: 0
       Patali Dirapata, Cromda Cromda Ripalo, Pata Pata, Ko Ko Ko
       Bokoro Dipoulito, Rondi Rondi Pepino, Pata Pata, Ko Ko Ko
       Emana Karassoli, Loucra Loucra Ponponto, Pata Pata, Ko Ko Ko.
   part header size: 22
   part type: "test:debugreply"
   part id: "3"
   part parameters: 0
   found a handler for part 'test:debugreply'
   debugreply: no reply
   payload chunk size: 0
   part header size: 43
   part type: "test:math"
   part id: "4"
   part parameters: 3
   ignoring unsupported advisory part test:math
   payload chunk size: 2
   payload chunk size: 0
   part header size: 29
   part type: "test:song"
   part id: "5"
   part parameters: 1
   found a handler for part 'test:song'
   ignoring unsupported advisory part test:song - randomparam
   payload chunk size: 0
   part header size: 16
   part type: "test:ping"
   part id: "6"
   part parameters: 0
   found a handler for part 'test:ping'
   received ping request (id 6)
   payload chunk size: 0
   part header size: 0
   end of bundle2 stream
   0 unread bytes
   3 total verses sung
 
 Unbundle with an unknown mandatory part
 (should abort)
 
   $ hg bundle2 --parts --unknown ../unknown.hg2
 
   $ hg unbundle2 < ../unknown.hg2
   The choir starts singing:
       Patali Dirapata, Cromda Cromda Ripalo, Pata Pata, Ko Ko Ko
       Bokoro Dipoulito, Rondi Rondi Pepino, Pata Pata, Ko Ko Ko
       Emana Karassoli, Loucra Loucra Ponponto, Pata Pata, Ko Ko Ko.
   debugreply: no reply
   0 unread bytes
   abort: missing support for test:unknown
   [255]
 
 Unbundle with an unknown mandatory part parameters
 (should abort)
 
   $ hg bundle2 --unknownparams ../unknown.hg2
 
   $ hg unbundle2 < ../unknown.hg2
   0 unread bytes
   abort: missing support for test:song - randomparams
   [255]
 
 unbundle with a reply
 
   $ hg bundle2 --parts --reply ../parts-reply.hg2
   $ hg unbundle2 ../reply.hg2 < ../parts-reply.hg2
   0 unread bytes
   3 total verses sung
 
 The reply is a bundle
 
   $ cat ../reply.hg2
   HG2Y\x00\x00\x00\x00\x00\x00\x00\x1f (esc)
   b2x:output\x00\x00\x00\x00\x00\x01\x0b\x01in-reply-to3\x00\x00\x00\xd9The choir starts singing: (esc)
       Patali Dirapata, Cromda Cromda Ripalo, Pata Pata, Ko Ko Ko
       Bokoro Dipoulito, Rondi Rondi Pepino, Pata Pata, Ko Ko Ko
       Emana Karassoli, Loucra Loucra Ponponto, Pata Pata, Ko Ko Ko.
   \x00\x00\x00\x00\x00\x00\x00\x1f (esc)
   b2x:output\x00\x00\x00\x01\x00\x01\x0b\x01in-reply-to4\x00\x00\x00\xc9debugreply: capabilities: (esc)
   debugreply:     'city=!'
   debugreply:         'celeste,ville'
   debugreply:     'elephants'
   debugreply:         'babar'
   debugreply:         'celeste'
   debugreply:     'ping-pong'
   \x00\x00\x00\x00\x00\x00\x00\x1e	test:pong\x00\x00\x00\x02\x01\x00\x0b\x01in-reply-to7\x00\x00\x00\x00\x00\x00\x00\x1f (esc)
   b2x:output\x00\x00\x00\x03\x00\x01\x0b\x01in-reply-to7\x00\x00\x00=received ping request (id 7) (esc)
   replying to ping request (id 7)
   \x00\x00\x00\x00\x00\x00\x00\x00 (no-eol) (esc)
 
 The reply is valid
 
   $ hg statbundle2 < ../reply.hg2
   options count: 0
     :b2x:output:
       mandatory: 0
       advisory: 1
       payload: 217 bytes
     :b2x:output:
       mandatory: 0
       advisory: 1
       payload: 201 bytes
     :test:pong:
       mandatory: 1
       advisory: 0
       payload: 0 bytes
     :b2x:output:
       mandatory: 0
       advisory: 1
       payload: 61 bytes
   parts count:   4
 
 Unbundle the reply to get the output:
 
   $ hg unbundle2 < ../reply.hg2
   remote: The choir starts singing:
   remote:     Patali Dirapata, Cromda Cromda Ripalo, Pata Pata, Ko Ko Ko
   remote:     Bokoro Dipoulito, Rondi Rondi Pepino, Pata Pata, Ko Ko Ko
   remote:     Emana Karassoli, Loucra Loucra Ponponto, Pata Pata, Ko Ko Ko.
   remote: debugreply: capabilities:
   remote: debugreply:     'city=!'
   remote: debugreply:         'celeste,ville'
   remote: debugreply:     'elephants'
   remote: debugreply:         'babar'
   remote: debugreply:         'celeste'
   remote: debugreply:     'ping-pong'
   remote: received ping request (id 7)
   remote: replying to ping request (id 7)
   0 unread bytes
 
 Test push race detection
 
   $ hg bundle2 --pushrace ../part-race.hg2
 
   $ hg unbundle2 < ../part-race.hg2
   0 unread bytes
   abort: push race: repository changed while pushing - please try again
   [255]
 
 Support for changegroup
 ===================================
 
   $ hg unbundle $TESTDIR/bundles/rebase.hg
   adding changesets
   adding manifests
   adding file changes
   added 8 changesets with 7 changes to 7 files (+3 heads)
   (run 'hg heads' to see heads, 'hg merge' to merge)
 
   $ hg log -G
   o  8:02de42196ebe draft Nicolas Dumazet <[e-mail]>  H
   |
   | o  7:eea13746799a draft Nicolas Dumazet <[e-mail]>  G
   |/|
   o |  6:24b6387c8c8c draft Nicolas Dumazet <[e-mail]>  F
   | |
   | o  5:9520eea781bc draft Nicolas Dumazet <[e-mail]>  E
   |/
   | o  4:32af7686d403 draft Nicolas Dumazet <[e-mail]>  D
   | |
   | o  3:5fddd98957c8 draft Nicolas Dumazet <[e-mail]>  C
   | |
   | o  2:42ccdea3bb16 draft Nicolas Dumazet <[e-mail]>  B
   |/
   o  1:cd010b8cd998 draft Nicolas Dumazet <[e-mail]>  A
   
   @  0:3903775176ed draft test  a
   
 
   $ hg bundle2 --debug --rev '8+7+5+4' ../rev.hg2
   4 changesets found
   list of changesets:
   32af7686d403cf45b5d95f2d70cebea587ac806a
   9520eea781bcca16c1e15acc0ba14335a0e8e5ba
   eea13746799a9e0bfd88f29d3c2e9dc9389f524f
   02de42196ebee42ef284b6780a87cdc96e8eaab6
   start emission of HG2Y stream
   bundle parameter: 
   start of parts
   bundle part: "b2x:changegroup"
   bundling: 1/4 changesets (25.00%)
   bundling: 2/4 changesets (50.00%)
   bundling: 3/4 changesets (75.00%)
   bundling: 4/4 changesets (100.00%)
   bundling: 1/4 manifests (25.00%)
   bundling: 2/4 manifests (50.00%)
   bundling: 3/4 manifests (75.00%)
   bundling: 4/4 manifests (100.00%)
   bundling: D 1/3 files (33.33%)
   bundling: E 2/3 files (66.67%)
   bundling: H 3/3 files (100.00%)
   end of bundle
 
   $ cat ../rev.hg2
   HG2Y\x00\x00\x00\x00\x00\x00\x00\x16\x0fb2x:changegroup\x00\x00\x00\x00\x00\x00\x00\x00\x06\x13\x00\x00\x00\xa42\xafv\x86\xd4\x03\xcfE\xb5\xd9_-p\xce\xbe\xa5\x87\xac\x80j_\xdd\xd9\x89W\xc8\xa5JMCm\xfe\x1d\xa9\xd8\x7f!\xa1\xb9{\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x002\xafv\x86\xd4\x03\xcfE\xb5\xd9_-p\xce\xbe\xa5\x87\xac\x80j\x00\x00\x00\x00\x00\x00\x00)\x00\x00\x00)6e1f4c47ecb533ffd0c8e52cdc88afb6cd39e20c (esc)
   \x00\x00\x00f\x00\x00\x00h\x00\x00\x00\x02D (esc)
   \x00\x00\x00i\x00\x00\x00j\x00\x00\x00\x01D\x00\x00\x00\xa4\x95 \xee\xa7\x81\xbc\xca\x16\xc1\xe1Z\xcc\x0b\xa1C5\xa0\xe8\xe5\xba\xcd\x01\x0b\x8c\xd9\x98\xf3\x98\x1aZ\x81\x15\xf9O\x8d\xa4\xabP`\x89\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x95 \xee\xa7\x81\xbc\xca\x16\xc1\xe1Z\xcc\x0b\xa1C5\xa0\xe8\xe5\xba\x00\x00\x00\x00\x00\x00\x00)\x00\x00\x00)4dece9c826f69490507b98c6383a3009b295837d (esc)
   \x00\x00\x00f\x00\x00\x00h\x00\x00\x00\x02E (esc)
   \x00\x00\x00i\x00\x00\x00j\x00\x00\x00\x01E\x00\x00\x00\xa2\xee\xa17Fy\x9a\x9e\x0b\xfd\x88\xf2\x9d<.\x9d\xc98\x9fRO$\xb68|\x8c\x8c\xae7\x17\x88\x80\xf3\xfa\x95\xde\xd3\xcb\x1c\xf7\x85\x95 \xee\xa7\x81\xbc\xca\x16\xc1\xe1Z\xcc\x0b\xa1C5\xa0\xe8\xe5\xba\xee\xa17Fy\x9a\x9e\x0b\xfd\x88\xf2\x9d<.\x9d\xc98\x9fRO\x00\x00\x00\x00\x00\x00\x00)\x00\x00\x00)365b93d57fdf4814e2b5911d6bacff2b12014441 (esc)
   \x00\x00\x00f\x00\x00\x00h\x00\x00\x00\x00\x00\x00\x00i\x00\x00\x00j\x00\x00\x00\x01G\x00\x00\x00\xa4\x02\xdeB\x19n\xbe\xe4.\xf2\x84\xb6x (esc)
   \x87\xcd\xc9n\x8e\xaa\xb6$\xb68|\x8c\x8c\xae7\x17\x88\x80\xf3\xfa\x95\xde\xd3\xcb\x1c\xf7\x85\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\xdeB\x19n\xbe\xe4.\xf2\x84\xb6x (esc)
   \x87\xcd\xc9n\x8e\xaa\xb6\x00\x00\x00\x00\x00\x00\x00)\x00\x00\x00)8bee48edc7318541fc0013ee41b089276a8c24bf (esc)
   \x00\x00\x00f\x00\x00\x00f\x00\x00\x00\x02H (esc)
   \x00\x00\x00g\x00\x00\x00h\x00\x00\x00\x01H\x00\x00\x00\x00\x00\x00\x00\x8bn\x1fLG\xec\xb53\xff\xd0\xc8\xe5,\xdc\x88\xaf\xb6\xcd9\xe2\x0cf\xa5\xa0\x18\x17\xfd\xf5#\x9c'8\x02\xb5\xb7a\x8d\x05\x1c\x89\xe4\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x002\xafv\x86\xd4\x03\xcfE\xb5\xd9_-p\xce\xbe\xa5\x87\xac\x80j\x00\x00\x00\x81\x00\x00\x00\x81\x00\x00\x00+D\x00c3f1ca2924c16a19b0656a84900e504e5b0aec2d (esc)
   \x00\x00\x00\x8bM\xec\xe9\xc8&\xf6\x94\x90P{\x98\xc68:0	\xb2\x95\x83}\x00}\x8c\x9d\x88\x84\x13%\xf5\xc6\xb0cq\xb3[N\x8a+\x1a\x83\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x95 \xee\xa7\x81\xbc\xca\x16\xc1\xe1Z\xcc\x0b\xa1C5\xa0\xe8\xe5\xba\x00\x00\x00+\x00\x00\x00\xac\x00\x00\x00+E\x009c6fd0350a6c0d0c49d4a9c5017cf07043f54e58 (esc)
   \x00\x00\x00\x8b6[\x93\xd5\x7f\xdfH\x14\xe2\xb5\x91\x1dk\xac\xff+\x12\x01DA(\xa5\x84\xc6^\xf1!\xf8\x9e\xb6j\xb7\xd0\xbc\x15=\x80\x99\xe7\xceM\xec\xe9\xc8&\xf6\x94\x90P{\x98\xc68:0	\xb2\x95\x83}\xee\xa17Fy\x9a\x9e\x0b\xfd\x88\xf2\x9d<.\x9d\xc98\x9fRO\x00\x00\x00V\x00\x00\x00V\x00\x00\x00+F\x0022bfcfd62a21a3287edbd4d656218d0f525ed76a (esc)
   \x00\x00\x00\x97\x8b\xeeH\xed\xc71\x85A\xfc\x00\x13\xeeA\xb0\x89'j\x8c$\xbf(\xa5\x84\xc6^\xf1!\xf8\x9e\xb6j\xb7\xd0\xbc\x15=\x80\x99\xe7\xce\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\xdeB\x19n\xbe\xe4.\xf2\x84\xb6x (esc)
   \x87\xcd\xc9n\x8e\xaa\xb6\x00\x00\x00+\x00\x00\x00V\x00\x00\x00\x00\x00\x00\x00\x81\x00\x00\x00\x81\x00\x00\x00+H\x008500189e74a9e0475e822093bc7db0d631aeb0b4 (esc)
   \x00\x00\x00\x00\x00\x00\x00\x05D\x00\x00\x00b\xc3\xf1\xca)$\xc1j\x19\xb0ej\x84\x90\x0ePN[ (esc)
   \xec-\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x002\xafv\x86\xd4\x03\xcfE\xb5\xd9_-p\xce\xbe\xa5\x87\xac\x80j\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02D (esc)
   \x00\x00\x00\x00\x00\x00\x00\x05E\x00\x00\x00b\x9co\xd05 (esc)
   l\r (no-eol) (esc)
   \x0cI\xd4\xa9\xc5\x01|\xf0pC\xf5NX\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x95 \xee\xa7\x81\xbc\xca\x16\xc1\xe1Z\xcc\x0b\xa1C5\xa0\xe8\xe5\xba\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02E (esc)
   \x00\x00\x00\x00\x00\x00\x00\x05H\x00\x00\x00b\x85\x00\x18\x9et\xa9\xe0G^\x82 \x93\xbc}\xb0\xd61\xae\xb0\xb4\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\xdeB\x19n\xbe\xe4.\xf2\x84\xb6x (esc)
   \x87\xcd\xc9n\x8e\xaa\xb6\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02H (esc)
   \x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00 (no-eol) (esc)
 
   $ hg unbundle2 < ../rev.hg2
   adding changesets
   adding manifests
   adding file changes
   added 0 changesets with 0 changes to 3 files
   0 unread bytes
   addchangegroup return: 1
 
 with reply
 
   $ hg bundle2 --rev '8+7+5+4' --reply ../rev-rr.hg2
   $ hg unbundle2 ../rev-reply.hg2 < ../rev-rr.hg2
   0 unread bytes
   addchangegroup return: 1
 
   $ cat ../rev-reply.hg2
   HG2Y\x00\x00\x00\x00\x00\x00\x003\x15b2x:reply:changegroup\x00\x00\x00\x00\x00\x02\x0b\x01\x06\x01in-reply-to1return1\x00\x00\x00\x00\x00\x00\x00\x1f (esc)
   b2x:output\x00\x00\x00\x01\x00\x01\x0b\x01in-reply-to1\x00\x00\x00dadding changesets (esc)
   adding manifests
   adding file changes
   added 0 changesets with 0 changes to 3 files
   \x00\x00\x00\x00\x00\x00\x00\x00 (no-eol) (esc)
 
 Check handling of exception during generation.
 ----------------------------------------------
 
   $ hg bundle2 --genraise > ../genfailed.hg2
   abort: Someone set up us the bomb!
   [255]
 
 Should still be a valid bundle
 
   $ cat ../genfailed.hg2
   HG2Y\x00\x00\x00\x00\x00\x00\x00\x11 (esc)
   b2x:output\x00\x00\x00\x00\x00\x00\xff\xff\xff\xff\x00\x00\x00L\x0fb2x:error:abort\x00\x00\x00\x00\x01\x00\x07-messageunexpected error: Someone set up us the bomb!\x00\x00\x00\x00\x00\x00\x00\x00 (no-eol) (esc)
 
 And its handling on the other size raise a clean exception
 
   $ cat ../genfailed.hg2 | hg unbundle2
   0 unread bytes
   abort: unexpected error: Someone set up us the bomb!
   [255]
 
 
   $ cd ..