1. If "git fetch-pack" is called with "--all", "--depth", and an
explicit existing non-tag reference to fetch, then it falsely reports
that the reference was not found, even though it was fetched
correctly.
2. If "git fetch-pack" is called with "--all", "--depth", and an
explicit existing tag reference to fetch, then it segfaults in
filter_refs() because return_refs is used without having been
initialized.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>