Merge branch 'nd/oneline-sha1-name-from-specific-ref'

* nd/oneline-sha1-name-from-specific-ref: get_sha1: handle special case $commit^{/} get_sha1: support $commit^{/regex} syntax get_sha1_oneline: make callers prepare the commit list to traverse get_sha1_oneline: fix lifespan rule of temp_commit_buffer variable