[PATCH v3 0/3] rev-parse: strengthen validation of ref@{n} references

This series changes git rev-parse so that references of the form:

       ref@{n}

cause rev-parse to fail with a non-zero status code if n >= size of the reference log for ref.

The first commit implements the changed behaviour; the second commit replaces uses of fprintf (within sha1_name.c) with warning; the third commit updates the tests to include tests for the changed behaviour.

This is the third revision of this series. It differs from the first in that it uses die rather than error to report the condition and thus exits early, without generating any output on stdout for the failing argument. It also reports just a single fatal message instead of both an error message and a fatal message.

The original patch and this revision are both based on suggestions from Junio. Corrections to diagnostic output inspired by Jonathan Nieder's review.

Jon Seymour (3):
  rev-parse: exit with non-zero status if ref@{n} is not valid.
  sha1_name.c: use warning in preference to fprintf(stderr
  rev-parse: tests git rev-parse --verify master@{n}, for various n

 sha1_name.c                    |   20 +++++++++++---------
 t/t1503-rev-parse-verify.sh    |   11 +++++++++++
 t/t1506-rev-parse-diagnosis.sh |    9 +++++++++
 3 files changed, 31 insertions(+), 9 deletions(-)