Merge branch 'js/maint-reflog-beyond-horizon'

* js/maint-reflog-beyond-horizon:
t1503: fix broken test_must_fail calls
rev-parse: tests git rev-parse --verify master@{n}, for various n
sha1_name.c: use warning in preference to fprintf(stderr
rev-parse: exit with non-zero status if ref@{n} is not valid.

diff --cc sha1_name.c
Simple merge