Re: Git silently broke push-options over ssh?

From: Jeff King <peff@peff.net>
Date: Oct 22, 2021, 20:53 UTC
Message-ID: <YXMku8V9cdHLfXt6@coredump.intra.peff.net>
In-Reply-To: <4aef40f2-43f8-eab3-a840-6e76c8b4afbb@cs-ware.de>

On Fri, Oct 22, 2021 at 07:27:14PM +0200, Sven Strickroth wrote:

> If I understood <https://opensource.googleblog.com/2018/05/introducing-git-protocol-version-2.html>
> correctly I have to enable the Git protocol version 2 and then the push
> options should work.

I don't think that is true. There is no v2 push protocol yet, so the push options must work over v0.

Show 20 quoted lines

> Now, when I try to use push options on Windows it does not work. I tried to
> debug it:
> 
> D:\TortoiseGit>set GIT_TRACE=2
> D:\TortoiseGit>set GIT_SSH=ssh.exe
> D:\TortoiseGit>set GIT_SSH_VARIANT=ssh
> D:\TortoiseGit>set GIT_PROTOCOL=version=2
> D:\TortoiseGit>git -c protocol.version=2 -c ssh.variant=ssh -c
> ssh.command=ssh push -v -o ci.skip origin master~23:testing
> 17:36:06.285346 exec-cmd.c:237          trace: resolved executable dir:
> C:/Program Files/Git/mingw64/bin
> 17:36:06.285346 git.c:455               trace: built-in: git push -v -o
> ci.skip origin 'master~23:testing'
> Pushing to gitlab.com:tortoisegit/tortoisegit.git
> 17:36:06.295270 run-command.c:666       trace: run_command: unset
> GIT_CONFIG_PARAMETERS GIT_PREFIX; ssh.exe git@gitlab.com 'git-receive-pack
> '\''tortoisegit/tortoisegit.git'\'''
> 
> As you can see, the "-o SendEnv" parameter not passed to ssh.exe and,
> therefore, I think the push option is not transferred to the server.

Push options don't go through the environment. The GIT_PROTOCOL magic for enabling v2 does, but push options themselves happen over the Git protocol. Try GIT_TRACE_PACKET for seeing the actual conversation. E.g.:

  $ GIT_TRACE_PACKET=1 GIT_TRACE=1 git push -o foo git.peff.net:foo.git
  16:49:19.236448 git.c:455               trace: built-in: git push -o foo git.peff.net:foo.git
  16:49:19.237409 run-command.c:666       trace: run_command: unset GIT_PREFIX; ssh git.peff.net 'git-receive-pack '\''foo.git'\'''
  16:49:19.423323 pkt-line.c:80           packet:         push< b2f0a7f47f5f2aebe1e7fceff19a57de20a78c06 refs/heads/master\0report-status report-status-v2 delete-refs side-band-64k quiet atomic ofs-delta push-options object-format=sha1 agent=git/2.30.2
  16:49:19.423399 pkt-line.c:80           packet:         push< 0000
  16:49:19.431385 pkt-line.c:80           packet:         push> 0000
  16:49:19.431421 pkt-line.c:80           packet:         push> foo
  16:49:19.431442 pkt-line.c:80           packet:         push> 0000
  Everything up-to-date

On the server side, receive-pack will stick them in the environment to communicate them to hooks, etc, but you wouldn't be able to see that from the client.

Do note that I had to set receive.advertisePushOptions on the server to make it work (though if it's not set, the client should complain loudly). If you're pushing to gitlab.com they've presumably set up the server side appropriately.

-Peff