Instead of having the client advertise a particular version
number in the git protocol, we have managed extensions and
backwards compatibility by having clients and servers
advertise capabilities that they support. This is far more
robust than having each side consult a table of
known versions, and provides sufficient information for the
protocol interaction to complete.
However, it does not allow servers to keep statistics on
which client versions are being used. This information is
not necessary to complete the network request (the
capabilities provide enough information for that), but it
may be helpful to conduct a general survey of client
versions in use.
We already send the client version in the user-agent header
for http requests; adding it here allows us to gather
similar statistics for non-http requests.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is basically a fancy way of saying "git/$GIT_VERSION",
except that it is overridable at build-time and through the
environment. Which means that people who don't want to
advertise their git version (for privacy or security
reasons) can tweak it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The global git_version_string currently lives in git.c, but
doesn't have anything to do with the git wrapper. Let's move
it into its own file, where it will be more appropriate to
build more version-related functions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
