From Git commit 9c1e657a8f:
Currently, the packfile negotiation step within a Git fetch cannot be
done independent of sending the packfile, even though there is at
least one application wherein this is useful - push negotiation.
Therefore, make it possible for this negotiation step to be done
independently.
This feature is for protocol v2 only.
In the protocol, the main hindrance towards independent negotiation is
that the server can unilaterally decide to send the packfile. This is
solved by a "wait-for-done" argument: the server will then wait for
the client to say "done". In practice, the client will never say it;
instead it will cease requests once it is satisfied.
Advertising the server capability option "wait-for-done" is behind the
transport config: uploadpack.advertisewaitfordone, which by default is
false.
Change-Id: I5ebd3e99ad76b8943597216e23ced2ed38eb5224
64d0aaa2b6