Merge branch 'jk/fetch-pack' into maint

"git fetch" that fetches a commit using the allow-tip-sha1-in-want
extension could have failed to fetch all the requested refs.

* jk/fetch-pack:
fetch-pack: remove dead assignment to ref->new_sha1
fetch_refs_via_pack: free extra copy of refs
filter_ref: make a copy of extra "sought" entries
filter_ref: avoid overwriting ref->old_sha1 with garbage

diff --cc t/t5516-fetch-push.sh
Simple merge

diff --cc transport.c
Simple merge