On Tue,  6 Feb 2018 17:12:49 -0800
Brandon Williams [off-list ref] wrote:

 .gitignore                              |   1 +
 Documentation/technical/protocol-v2.txt | 114 +++++++++++++++
 Makefile                                |   2 +
 builtin.h                               |   1 +
 builtin/serve.c                         |  30 ++++
 git.c                                   |   1 +
 serve.c                                 | 250 ++++++++++++++++++++++++++++++++
 serve.h                                 |  15 ++
 t/t5701-git-serve.sh                    |  60 ++++++++
 9 files changed, 474 insertions(+)
 create mode 100644 Documentation/technical/protocol-v2.txt
 create mode 100644 builtin/serve.c
 create mode 100644 serve.c
 create mode 100644 serve.h
 create mode 100755 t/t5701-git-serve.sh

As someone who is implementing the server side of protocol V2 in JGit, I
now have a bit more insight into this :-)

First of all, I used to not have a strong opinion on the existence of a
new endpoint, but now I think that it's better to *not* have git-serve.
As it is, as far as I can tell, upload-pack also needs to support (and
does support, as of the end of this patch set) protocol v2 anyway, so it
might be better to merely upgrade upload-pack.

+A client then responds to select the command it wants with any particular
+capabilities or arguments.  There is then an optional section where the
+client can provide any command specific parameters or queries.
+
+    command-request = command
+		      capability-list
+		      (command-args)

If you are stating that this is optional, write "*1command-args". (RFC
5234 also supports square brackets, but "*1" is already used in
pack-protocol.txt and http-protocol.txt.)

+		      flush-pkt
+    command = PKT-LINE("command=" key LF)
+    command-args = delim-pkt
+		   *arg
+    arg = 1*CHAR

arg should be wrapped in PKT-LINE, I think, and terminated by an LF.