eff40457a fetch: fix segfault in --negotiate-only without --negotiation-tip=*
6a24cc71e submodule--helper: remove redundant include
d5659f856 help: convert git_cmd to page in one place
5632e838f khash: clarify that allocations never fail
52a47aea7 t7509: avoid direct file access for writing CHERRY_PICK_HEAD
ae815940f t1415: avoid direct filesystem access for writing refs
ba8c2680e t6402: preserve git exit status code