[PATCH v4 00/35] protocol version 2

Lots of changes since v3 (well more than between v2 and v3). Thanks for all of the reviews on the last round, the series is getting more polished.

 * Eliminated the "# service" line from the response from an HTTP
   server.  This means that the response to a v2 request is exactly the
   same regardless of which transport you use!  Docs for this have been
   added as well.
 * Changed how ref-patterns work with the `ls-refs` command.  Instead of
   using wildmatch all patterns must either match exactly or they can
   contain a single '*' character at the end to mean that the prefix
   must match.  Docs for this have also been added.
 * Lots of updates to the docs.  Including documenting the
   `stateless-connect` remote-helper command used by remote-curl to
   handle the http transport.
 * Fixed a number of bugs with the `fetch` command, one of which didn't
   use objects from configured alternates.

Brandon Williams (35):
  pkt-line: introduce packet_read_with_status
  pkt-line: allow peeking a packet line without consuming it
  pkt-line: add delim packet support
  upload-pack: convert to a builtin
  upload-pack: factor out processing lines
  transport: use get_refs_via_connect to get refs
  connect: convert get_remote_heads to use struct packet_reader
  connect: discover protocol version outside of get_remote_heads
  transport: store protocol version
  protocol: introduce enum protocol_version value protocol_v2
  test-pkt-line: introduce a packet-line test helper
  serve: introduce git-serve
  ls-refs: introduce ls-refs server command
  connect: request remote refs using v2
  transport: convert get_refs_list to take a list of ref patterns
  transport: convert transport_get_remote_refs to take a list of ref
    patterns
  ls-remote: pass ref patterns when requesting a remote's refs
  fetch: pass ref patterns when fetching
  push: pass ref patterns when pushing
  upload-pack: introduce fetch server command
  fetch-pack: perform a fetch using v2
  fetch-pack: support shallow requests
  connect: refactor git_connect to only get the protocol version once
  connect: don't request v2 when pushing
  transport-helper: remove name parameter
  transport-helper: refactor process_connect_service
  transport-helper: introduce stateless-connect
  pkt-line: add packet_buf_write_len function
  remote-curl: create copy of the service name
  remote-curl: store the protocol version the server responded with
  http: allow providing extra headers for http requests
  http: don't always add Git-Protocol header
  http: eliminate "# service" line when using protocol v2
  remote-curl: implement stateless-connect command
  remote-curl: don't request v2 when pushing

 .gitignore                              |   1 +
 Documentation/gitremote-helpers.txt     |  32 ++
 Documentation/technical/protocol-v2.txt | 401 +++++++++++++++
 Makefile                                |   7 +-
 builtin.h                               |   2 +
 builtin/clone.c                         |   2 +-
 builtin/fetch-pack.c                    |  20 +-
 builtin/fetch.c                         |  18 +-
 builtin/ls-remote.c                     |  12 +-
 builtin/receive-pack.c                  |   6 +
 builtin/remote.c                        |   2 +-
 builtin/send-pack.c                     |  20 +-
 builtin/serve.c                         |  30 ++
 builtin/upload-pack.c                   |  74 +++
 connect.c                               | 364 ++++++++++----
 connect.h                               |   7 +
 fetch-pack.c                            | 339 ++++++++++++-
 fetch-pack.h                            |   4 +-
 git.c                                   |   2 +
 http-backend.c                          |   8 +-
 http.c                                  |  25 +-
 http.h                                  |   7 +
 ls-refs.c                               | 144 ++++++
 ls-refs.h                               |   9 +
 pkt-line.c                              | 147 +++++-
 pkt-line.h                              |  78 +++
 protocol.c                              |   2 +
 protocol.h                              |   1 +
 refs.c                                  |  14 +
 refs.h                                  |   7 +
 remote-curl.c                           | 278 ++++++++++-
 remote.h                                |  11 +-
 serve.c                                 | 260 ++++++++++
 serve.h                                 |  15 +
 t/helper/test-pkt-line.c                |  64 +++
 t/t5701-git-serve.sh                    | 176 +++++++
 t/t5702-protocol-v2.sh                  | 273 +++++++++++
 transport-helper.c                      |  87 ++--
 transport-internal.h                    |   9 +-
 transport.c                             | 125 +++--
 transport.h                             |  18 +-
 upload-pack.c                           | 616 ++++++++++++++++++------
 upload-pack.h                           |  21 +
 43 files changed, 3370 insertions(+), 368 deletions(-)
 create mode 100644 Documentation/technical/protocol-v2.txt
 create mode 100644 builtin/serve.c
 create mode 100644 builtin/upload-pack.c
 create mode 100644 ls-refs.c
 create mode 100644 ls-refs.h
 create mode 100644 serve.c
 create mode 100644 serve.h
 create mode 100644 t/helper/test-pkt-line.c
 create mode 100755 t/t5701-git-serve.sh
 create mode 100755 t/t5702-protocol-v2.sh
 create mode 100644 upload-pack.h