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