$ . $TESTDIR/wireprotohelpers.sh

  $ hg init server

  $ enablehttpv2 server

  $ cd server

  $ hg debugdrawdag << EOF

  > C D

  > |/

  > B

  > |

  > A

  > EOF

  $ hg up B

  2 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg branch branch1

  marked working directory as branch branch1

  (branches are permanent and global, did you want a bookmark?)

  $ echo b1 > foo

  $ hg -q commit -A -m 'branch 1'

  $ hg up B

  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ hg branch branch2

  marked working directory as branch branch2

  $ echo b2 > foo

  $ hg -q commit -A -m 'branch 2'

  $ hg log -T '{rev}:{node} {branch} {desc}\n'

  5:224161c7589aa48fa83a48feff5e95b56ae327fc branch2 branch 2

  4:b5faacdfd2633768cb3152336cc0953381266688 branch1 branch 1

  3:be0ef73c17ade3fc89dc41701eb9fc3a91b58282 default D

  2:26805aba1e600a82e93661149f2313866a221a7b default C

  1:112478962961147124edd43549aedd1a335e44bf default B

  0:426bada5c67598ca65036d57d9e4b64b0c1ce7a0 default A

  $ hg serve -p $HGPORT -d --pid-file hg.pid -E error.log

  $ cat hg.pid > $DAEMON_PIDS

No arguments returns something reasonable

  $ sendhttpv2peer << EOF

  > command branchmap

  > EOF

  creating http peer for wire protocol version 2

  sending branchmap command

  s>     POST /api/exp-http-v2-0001/ro/branchmap HTTP/1.1\r\n

  s>     Accept-Encoding: identity\r\n

  s>     accept: application/mercurial-exp-framing-0003\r\n

  s>     content-type: application/mercurial-exp-framing-0003\r\n

  s>     content-length: 24\r\n

  s>     host: $LOCALIP:$HGPORT\r\n (glob)

  s>     user-agent: Mercurial debugwireproto\r\n

  s>     \r\n

  s>     \x10\x00\x00\x01\x00\x01\x01\x11\xa1DnameIbranchmap

  s> makefile('rb', None)

  s>     HTTP/1.1 200 OK\r\n

  s>     Server: testing stub value\r\n

  s>     Date: $HTTP_DATE$\r\n

  s>     Content-Type: application/mercurial-exp-framing-0003\r\n

  s>     Transfer-Encoding: chunked\r\n

  s>     \r\n

  s>     78\r\n

  s>     p\x00\x00\x01\x00\x02\x01F

  s>     \xa3Gbranch1\x81T\xb5\xfa\xac\xdf\xd2c7h\xcb1R3l\xc0\x953\x81&f\x88Gbranch2\x81T"Aa\xc7X\x9a\xa4\x8f\xa8:H\xfe\xff^\x95\xb5j\xe3\'\xfcGdefault\x82T&\x80Z\xba\x1e`\n

  s>     \x82\xe96a\x14\x9f#\x13\x86j"\x1a{T\xbe\x0e\xf7<\x17\xad\xe3\xfc\x89\xdcAp\x1e\xb9\xfc:\x91\xb5\x82\x82

  s>     \r\n

  received frame(size=112; request=1; stream=2; streamflags=stream-begin; type=bytes-response; flags=eos|cbor)

  s>     0\r\n

  s>     \r\n

  response: [{b'branch1': [b'\xb5\xfa\xac\xdf\xd2c7h\xcb1R3l\xc0\x953\x81&f\x88'], b'branch2': [b'"Aa\xc7X\x9a\xa4\x8f\xa8:H\xfe\xff^\x95\xb5j\xe3\'\xfc'], b'default': [b'&\x80Z\xba\x1e`\n\x82\xe96a\x14\x9f#\x13\x86j"\x1a{', b'\xbe\x0e\xf7<\x17\xad\xe3\xfc\x89\xdcAp\x1e\xb9\xfc:\x91\xb5\x82\x82']}]

  $ cat error.log