The signature for the reflog is not something which changes
dynamically. Almost all uses will be NULL, since we want for the
repository's default identity to be used, making it noise.
In order to allow for changing the identity, we instead provide
git_repository_set_ident() and git_repository_ident() which allow a user
to override the choice of signature.
With opportunistic ref updates, git has introduced the concept of having
base refspecs *and* refspecs that are active for a particular fetch.
Let's start by letting the user override the refspecs for download.
The current FETCH_HEAD parsing code assumes that a quote must end the
branch name. Git however allows for quotes as part of a branch name,
which causes us to consider the FETCH_HEAD file as invalid.
Instead of searching for a single quote char, search for a quote char
followed by SP, which is not a valid part of a ref name.
Cloning from an empty repo must set master's upstream to origin's
master, even if neither of them exist.
Fetching from a non-empty origin must then mark the master branch
for-merge. This currently fails.
