Merge branch 'ps/weak-sha1-for-tail-sum-fix' into ps/meson-weak-sha1-build

* ps/weak-sha1-for-tail-sum-fix:
  ci: exercise unsafe OpenSSL backend
  builtin/fast-import: fix segfault with unsafe SHA1 backend
  bulk-checkin: fix segfault with unsafe SHA1 backend

diff --cc builtin/fast-import.c
Simple merge

diff --cc bulk-checkin.c
Simple merge

diff --cc ci/run-build-and-tests.sh
Simple merge