tests/test-bundle2-remote-changegroup.t

cborutil: implement sans I/O decoder

The vendored CBOR package decodes by calling read(n) on an object.
There are a number of disadvantages to this:

* Uses blocking I/O. If sufficient data is not available, the decoder
  will hang until it is.
* No support for partial reads. If the read(n) returns less data than
  requested, the decoder raises an error.
* Requires the use of a file like object. If the original data is in
  say a buffer, we need to "cast" it to e.g. a BytesIO to appease the
  decoder.

In addition, the vendored CBOR decoder doesn't provide flexibility
that we desire. Specifically:

* It buffers indefinite length bytestrings instead of streaming them.
* It doesn't allow limiting the set of types that can be decoded. This
  property is useful when implementing a "hardened" decoder that is
  less susceptible to abusive input.
* It doesn't provide sufficient "hook points" and introspection to
  institute checks around behavior. These are useful for implementing
  a "hardened" decoder.

This all adds up to a reasonable set of justifications for writing our
own decoder.

So, this commit implements our own CBOR decoder.

At the heart of the decoder is a function that decodes a single "item"
from a buffer. This item can be a complete simple value or a special
value, such as "start of array." Using this function, we can build a
decoder that effectively iterates over the stream of decoded items and
builds up higher-level values, such as arrays, maps, sets, and indefinite
length bytestrings. And we can do this without performing I/O in the
decoder itself.

The core of the sans I/O decoder will probably not be used directly.
Instead, it is expected that we'll build utility functions for invoking
the decoder given specific input types. This will allow extreme
flexibility in how data is delivered to the decoder.

I'm pretty happy with the state of the decoder modulo the TODO items
to track wanted features to help with a "hardened" decoder. The one
thing I could be convinced to change is the handling of semantic tags.
Since we only support a single semantic tag (sets), I thought it would
be easier to handle them inline in decodeitem(). This is simpler now.
But if we add support for other semantic tags, it will likely be easier
to move semantic tag handling outside of decodeitem(). But, properly
supporting semantic tags opens up a whole can of worms, as many
semantic tags imply new types. I'm optimistic we won't need these in
Mercurial. But who knows.

I'm also pretty happy with the test coverage. Writing comprehensive
tests for partial decoding did flush out a handful of bugs. One
general improvement to testing would be fuzz testing for partial
decoding. I may implement that later. I also anticipate switching the
wire protocol code to this new decoder will flush out any lingering
bugs.

Differential Revision: https://phab.mercurial-scm.org/D4414

#testcases sshv1 sshv2

#if sshv2
  $ cat >> $HGRCPATH << EOF
  > [experimental]
  > sshpeer.advertise-v2 = true
  > sshserver.support-v2 = true
  > EOF
#endif

Create an extension to test bundle2 remote-changegroup parts

  $ cat > bundle2.py << EOF
  > """A small extension to test bundle2 remote-changegroup parts.
  > 
  > Current bundle2 implementation doesn't provide a way to generate those
  > parts, so they must be created by extensions.
  > """
  > from mercurial import (
  >     bundle2,
  >     changegroup,
  >     discovery,
  >     exchange,
  >     pycompat,
  >     util,
  > )
  > 
  > def _getbundlechangegrouppart(bundler, repo, source, bundlecaps=None,
  >                               b2caps=None, heads=None, common=None,
  >                               **kwargs):
  >     """this function replaces the changegroup part handler for getbundle.
  >     It allows to create a set of arbitrary parts containing changegroups
  >     and remote-changegroups, as described in a bundle2maker file in the
  >     repository .hg/ directory.
  > 
  >     Each line of that bundle2maker file contain a description of the
  >     part to add:
  >       - changegroup common_revset heads_revset
  >           Creates a changegroup part based, using common_revset and
  >           heads_revset for outgoing
  >       - remote-changegroup url file
  >           Creates a remote-changegroup part for a bundle at the given
  >           url. Size and digest, as required by the client, are computed
  >           from the given file.
  >       - raw-remote-changegroup <python expression>
  >           Creates a remote-changegroup part with the data given in the
  >           Python expression as parameters. The Python expression is
  >           evaluated with eval, and is expected to be a dict.
  >     """
  >     def newpart(name, data=b''):
  >         """wrapper around bundler.newpart adding an extra part making the
  >         client output information about each processed part"""
  >         bundler.newpart(b'output', data=name)
  >         part = bundler.newpart(name, data=data)
  >         return part
  > 
  >     for line in open(repo.vfs.join(b'bundle2maker'), 'rb'):
  >         line = line.strip()
  >         try:
  >             verb, args = line.split(None, 1)
  >         except ValueError:
  >             verb, args = line, b''
  >         if verb == b'remote-changegroup':
  >            url, file = args.split()
  >            bundledata = open(file, 'rb').read()
  >            digest = util.digester.preferred(b2caps[b'digests'])
  >            d = util.digester([digest], bundledata)
  >            part = newpart(b'remote-changegroup')
  >            part.addparam(b'url', url)
  >            part.addparam(b'size', b'%d' % len(bundledata))
  >            part.addparam(b'digests', digest)
  >            part.addparam(b'digest:%s' % digest, d[digest])
  >         elif verb == b'raw-remote-changegroup':
  >            part = newpart(b'remote-changegroup')
  >            for k, v in eval(args).items():
  >                part.addparam(pycompat.sysbytes(k), pycompat.bytestr(v))
  >         elif verb == b'changegroup':
  >             _common, heads = args.split()
  >             common.extend(repo[r].node() for r in repo.revs(_common))
  >             heads = [repo[r].node() for r in repo.revs(heads)]
  >             outgoing = discovery.outgoing(repo, common, heads)
  >             cg = changegroup.makechangegroup(repo, outgoing, b'01',
  >                                              b'changegroup')
  >             newpart(b'changegroup', cg.getchunks())
  >         else:
  >             raise Exception('unknown verb')
  > 
  > exchange.getbundle2partsmapping[b'changegroup'] = _getbundlechangegrouppart
  > EOF

Start a simple HTTP server to serve bundles

  $ $PYTHON "$TESTDIR/dumbhttp.py" -p $HGPORT --pid dumb.pid
  $ cat dumb.pid >> $DAEMON_PIDS

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > ssh=$PYTHON "$TESTDIR/dummyssh"
  > logtemplate={rev}:{node|short} {phase} {author} {bookmarks} {desc|firstline}
  > EOF

  $ hg init repo

  $ hg -R repo unbundle $TESTDIR/bundles/rebase.hg
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg -R repo log -G
  o  7:02de42196ebe draft Nicolas Dumazet <[e-mail]>  H
  |
  | o  6:eea13746799a draft Nicolas Dumazet <[e-mail]>  G
  |/|
  o |  5:24b6387c8c8c draft Nicolas Dumazet <[e-mail]>  F
  | |
  | o  4:9520eea781bc draft Nicolas Dumazet <[e-mail]>  E
  |/
  | o  3:32af7686d403 draft Nicolas Dumazet <[e-mail]>  D
  | |
  | o  2:5fddd98957c8 draft Nicolas Dumazet <[e-mail]>  C
  | |
  | o  1:42ccdea3bb16 draft Nicolas Dumazet <[e-mail]>  B
  |/
  o  0:cd010b8cd998 draft Nicolas Dumazet <[e-mail]>  A
  
  $ hg clone repo orig
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cat > repo/.hg/hgrc << EOF
  > [extensions]
  > bundle2=$TESTTMP/bundle2.py
  > EOF

Test a pull with an remote-changegroup

  $ hg bundle -R repo --type v1 --base '0:4' -r '5:7' bundle.hg
  3 changesets found
  $ cat > repo/.hg/bundle2maker << EOF
  > remote-changegroup http://localhost:$HGPORT/bundle.hg bundle.hg
  > EOF
  $ hg clone orig clone -r 3 -r 4
  adding changesets
  adding manifests
  adding file changes
  added 5 changesets with 5 changes to 5 files (+1 heads)
  new changesets cd010b8cd998:9520eea781bc
  updating to branch default
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files (+1 heads)
  new changesets 24b6387c8c8c:02de42196ebe
  (run 'hg heads .' to see heads, 'hg merge' to merge)
  $ hg -R clone log -G
  o  7:02de42196ebe public Nicolas Dumazet <[e-mail]>  H
  |
  | o  6:eea13746799a public Nicolas Dumazet <[e-mail]>  G
  |/|
  o |  5:24b6387c8c8c public Nicolas Dumazet <[e-mail]>  F
  | |
  | o  4:9520eea781bc public Nicolas Dumazet <[e-mail]>  E
  |/
  | @  3:32af7686d403 public Nicolas Dumazet <[e-mail]>  D
  | |
  | o  2:5fddd98957c8 public Nicolas Dumazet <[e-mail]>  C
  | |
  | o  1:42ccdea3bb16 public Nicolas Dumazet <[e-mail]>  B
  |/
  o  0:cd010b8cd998 public Nicolas Dumazet <[e-mail]>  A
  
  $ rm -rf clone

Test a pull with an remote-changegroup and a following changegroup

  $ hg bundle -R repo --type v1 --base 2 -r '3:4' bundle2.hg
  2 changesets found
  $ cat > repo/.hg/bundle2maker << EOF
  > remote-changegroup http://localhost:$HGPORT/bundle2.hg bundle2.hg
  > changegroup 0:4 5:7
  > EOF
  $ hg clone orig clone -r 2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  new changesets cd010b8cd998:5fddd98957c8
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  remote: changegroup
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files (+1 heads)
  new changesets 32af7686d403:02de42196ebe
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg -R clone log -G
  o  7:02de42196ebe public Nicolas Dumazet <[e-mail]>  H
  |
  | o  6:eea13746799a public Nicolas Dumazet <[e-mail]>  G
  |/|
  o |  5:24b6387c8c8c public Nicolas Dumazet <[e-mail]>  F
  | |
  | o  4:9520eea781bc public Nicolas Dumazet <[e-mail]>  E
  |/
  | o  3:32af7686d403 public Nicolas Dumazet <[e-mail]>  D
  | |
  | @  2:5fddd98957c8 public Nicolas Dumazet <[e-mail]>  C
  | |
  | o  1:42ccdea3bb16 public Nicolas Dumazet <[e-mail]>  B
  |/
  o  0:cd010b8cd998 public Nicolas Dumazet <[e-mail]>  A
  
  $ rm -rf clone

Test a pull with a changegroup followed by an remote-changegroup

  $ hg bundle -R repo --type v1 --base '0:4' -r '5:7' bundle3.hg
  3 changesets found
  $ cat > repo/.hg/bundle2maker << EOF
  > changegroup 000000000000 :4
  > remote-changegroup http://localhost:$HGPORT/bundle3.hg bundle3.hg
  > EOF
  $ hg clone orig clone -r 2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  new changesets cd010b8cd998:5fddd98957c8
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 2 files (+1 heads)
  new changesets 32af7686d403:02de42196ebe
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg -R clone log -G
  o  7:02de42196ebe public Nicolas Dumazet <[e-mail]>  H
  |
  | o  6:eea13746799a public Nicolas Dumazet <[e-mail]>  G
  |/|
  o |  5:24b6387c8c8c public Nicolas Dumazet <[e-mail]>  F
  | |
  | o  4:9520eea781bc public Nicolas Dumazet <[e-mail]>  E
  |/
  | o  3:32af7686d403 public Nicolas Dumazet <[e-mail]>  D
  | |
  | @  2:5fddd98957c8 public Nicolas Dumazet <[e-mail]>  C
  | |
  | o  1:42ccdea3bb16 public Nicolas Dumazet <[e-mail]>  B
  |/
  o  0:cd010b8cd998 public Nicolas Dumazet <[e-mail]>  A
  
  $ rm -rf clone

Test a pull with two remote-changegroups and a changegroup

  $ hg bundle -R repo --type v1 --base 2 -r '3:4' bundle4.hg
  2 changesets found
  $ hg bundle -R repo --type v1 --base '3:4' -r '5:6' bundle5.hg
  2 changesets found
  $ cat > repo/.hg/bundle2maker << EOF
  > remote-changegroup http://localhost:$HGPORT/bundle4.hg bundle4.hg
  > remote-changegroup http://localhost:$HGPORT/bundle5.hg bundle5.hg
  > changegroup 0:6 7
  > EOF
  $ hg clone orig clone -r 2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  new changesets cd010b8cd998:5fddd98957c8
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  remote: changegroup
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 32af7686d403:02de42196ebe
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ hg -R clone log -G
  o  7:02de42196ebe public Nicolas Dumazet <[e-mail]>  H
  |
  | o  6:eea13746799a public Nicolas Dumazet <[e-mail]>  G
  |/|
  o |  5:24b6387c8c8c public Nicolas Dumazet <[e-mail]>  F
  | |
  | o  4:9520eea781bc public Nicolas Dumazet <[e-mail]>  E
  |/
  | o  3:32af7686d403 public Nicolas Dumazet <[e-mail]>  D
  | |
  | @  2:5fddd98957c8 public Nicolas Dumazet <[e-mail]>  C
  | |
  | o  1:42ccdea3bb16 public Nicolas Dumazet <[e-mail]>  B
  |/
  o  0:cd010b8cd998 public Nicolas Dumazet <[e-mail]>  A
  
  $ rm -rf clone

Hash digest tests

  $ hg bundle -R repo --type v1 -a bundle6.hg
  8 changesets found

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle6.hg', 'size': 1663, 'digests': 'sha1', 'digest:sha1': '2c880cfec23cff7d8f80c2f12958d1563cbdaba6'}
  > EOF
  $ hg clone ssh://user@dummy/repo clone
  requesting all changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf clone

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle6.hg', 'size': 1663, 'digests': 'md5', 'digest:md5': 'e22172c2907ef88794b7bea6642c2394'}
  > EOF
  $ hg clone ssh://user@dummy/repo clone
  requesting all changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf clone

Hash digest mismatch throws an error

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle6.hg', 'size': 1663, 'digests': 'sha1', 'digest:sha1': '0' * 40}
  > EOF
  $ hg clone ssh://user@dummy/repo clone
  requesting all changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  transaction abort!
  rollback completed
  abort: bundle at http://localhost:$HGPORT/bundle6.hg is corrupted:
  sha1 mismatch: expected 0000000000000000000000000000000000000000, got 2c880cfec23cff7d8f80c2f12958d1563cbdaba6
  [255]

Multiple hash digests can be given

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle6.hg', 'size': 1663, 'digests': 'md5 sha1', 'digest:md5': 'e22172c2907ef88794b7bea6642c2394', 'digest:sha1': '2c880cfec23cff7d8f80c2f12958d1563cbdaba6'}
  > EOF
  $ hg clone ssh://user@dummy/repo clone
  requesting all changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  new changesets cd010b8cd998:02de42196ebe
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm -rf clone

If either of the multiple hash digests mismatches, an error is thrown

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle6.hg', 'size': 1663, 'digests': 'md5 sha1', 'digest:md5': '0' * 32, 'digest:sha1': '2c880cfec23cff7d8f80c2f12958d1563cbdaba6'}
  > EOF
  $ hg clone ssh://user@dummy/repo clone
  requesting all changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  transaction abort!
  rollback completed
  abort: bundle at http://localhost:$HGPORT/bundle6.hg is corrupted:
  md5 mismatch: expected 00000000000000000000000000000000, got e22172c2907ef88794b7bea6642c2394
  [255]

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle6.hg', 'size': 1663, 'digests': 'md5 sha1', 'digest:md5': 'e22172c2907ef88794b7bea6642c2394', 'digest:sha1': '0' * 40}
  > EOF
  $ hg clone ssh://user@dummy/repo clone
  requesting all changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 8 changesets with 7 changes to 7 files (+2 heads)
  transaction abort!
  rollback completed
  abort: bundle at http://localhost:$HGPORT/bundle6.hg is corrupted:
  sha1 mismatch: expected 0000000000000000000000000000000000000000, got 2c880cfec23cff7d8f80c2f12958d1563cbdaba6
  [255]

Corruption tests

  $ hg clone orig clone -r 2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  new changesets cd010b8cd998:5fddd98957c8
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ cat > repo/.hg/bundle2maker << EOF
  > remote-changegroup http://localhost:$HGPORT/bundle4.hg bundle4.hg
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle5.hg', 'size': 578, 'digests': 'sha1', 'digest:sha1': '0' * 40}
  > changegroup 0:6 7
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 1 changes to 1 files
  transaction abort!
  rollback completed
  abort: bundle at http://localhost:$HGPORT/bundle5.hg is corrupted:
  sha1 mismatch: expected 0000000000000000000000000000000000000000, got f29485d6bfd37db99983cfc95ecb52f8ca396106
  [255]

The entire transaction has been rolled back in the pull above

  $ hg -R clone log -G
  @  2:5fddd98957c8 public Nicolas Dumazet <[e-mail]>  C
  |
  o  1:42ccdea3bb16 public Nicolas Dumazet <[e-mail]>  B
  |
  o  0:cd010b8cd998 public Nicolas Dumazet <[e-mail]>  A
  

No params

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: remote-changegroup: missing "url" param
  [255]

Missing size

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle4.hg'}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: remote-changegroup: missing "size" param
  [255]

Invalid size

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle4.hg', 'size': 'foo'}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: remote-changegroup: invalid value for param "size"
  [255]

Size mismatch

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle4.hg', 'size': 42}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  transaction abort!
  rollback completed
  abort: bundle at http://localhost:$HGPORT/bundle4.hg is corrupted:
  size mismatch: expected 42, got 581
  [255]

Unknown digest

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle4.hg', 'size': 581, 'digests': 'foo', 'digest:foo': 'bar'}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: missing support for remote-changegroup - digest:foo
  [255]

Missing digest

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'http://localhost:$HGPORT/bundle4.hg', 'size': 581, 'digests': 'sha1'}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: remote-changegroup: missing "digest:sha1" param
  [255]

Not an HTTP url

  $ cat > repo/.hg/bundle2maker << EOF
  > raw-remote-changegroup {'url': 'ssh://localhost:$HGPORT/bundle4.hg', 'size': 581}
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: remote-changegroup does not support ssh urls
  [255]

Not a bundle

  $ cat > notbundle.hg << EOF
  > foo
  > EOF
  $ cat > repo/.hg/bundle2maker << EOF
  > remote-changegroup http://localhost:$HGPORT/notbundle.hg notbundle.hg
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: http://localhost:$HGPORT/notbundle.hg: not a Mercurial bundle
  [255]

Not a bundle 1.0

  $ cat > notbundle10.hg << EOF
  > HG20
  > EOF
  $ cat > repo/.hg/bundle2maker << EOF
  > remote-changegroup http://localhost:$HGPORT/notbundle10.hg notbundle10.hg
  > EOF
  $ hg pull -R clone ssh://user@dummy/repo
  pulling from ssh://user@dummy/repo
  searching for changes
  remote: remote-changegroup
  abort: http://localhost:$HGPORT/notbundle10.hg: not a bundle version 1.0
  [255]

  $ hg -R clone log -G
  @  2:5fddd98957c8 public Nicolas Dumazet <[e-mail]>  C
  |
  o  1:42ccdea3bb16 public Nicolas Dumazet <[e-mail]>  B
  |
  o  0:cd010b8cd998 public Nicolas Dumazet <[e-mail]>  A
  
  $ rm -rf clone

  $ killdaemons.py