Bug: Cloning git repositories behind a proxy using the git:// protocol broken since 2.32

["Bezdeka, Florian" <florian.bezdeka@siemens.com>]

Hi all,

I just updated from git 2.30.2 (from Debian 11) to 2.39.0 (from Debian
testing) and realized that I can no longer clone repositories using the
git:// protocol.

There is one specialty in my setup: I'm located behind a proxy, so
GIT_PROXY_COMMAND is set. I'm usiung the oe-git-proxy script [1] here.
My environment provides the http_proxy variable and privoxy [2] is
running on the server side. That information should be sufficient to
reproduce.

I tried the following two repositories for testing:
 - git clone git://git.code.sf.net/p/linuxptp/code linuxptp
 - git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

The result is:
Cloning into 'linuxptp'...
fetch-pack: unexpected disconnect while reading sideband packet
fatal: early EOF
fatal: fetch-pack: invalid index-pack output

I was able to "git bisect" it to the following commit:
ae1a7eefffe6 ("fetch-pack: signal v2 server that we are done making requests")

Reverting this commit on top of the master branch fixes my issue.
All people involved in this commit should be in CC.

Looking at the TCP byte stream shows that the socket is closed after
the client received the first "part" of the packfile.

...
0032want ec3f28a0ac13df805278164f2c72e69676d13134
0032want 57caf5d94876e8329be65d2dc29d3c528b149724
0009done
0000000dpackfile

Let me know if you need further information. Hopefully this was the
correct way of submitting a bug to git...

Best regards,
Florian

[1] https://wiki.yoctoproject.org/wiki/Working_Behind_a_Network_Proxy
[2] https://www.privoxy.org/