[PATCH v2 0/2] add a reflog_exists and delete_reflog abstraction

This is a series adds two new functions to try to hide the reflog implementation details from the callers in checkout.c and reflog.c. It adds new functions to test if a reflog exists and to delete it, thus allowing checkout.c to perform this if-test-then-delete operation without having to know the internal implementation of reflogs (i.e. that they are files that live under .git/logs)

Additionally we change checkout.c to use ref_exists instead of file_exists when checking for ref existence. This fixes a bug when checkout could delete a valid reflog file if the branch was a packed ref. The tests have been updated to test for this bug.

Version 2:
 - Typos and fixes suggested by mhagger.
 - Break the checkout-deletes reflog bugfix out into a separate patch.

Ronnie Sahlberg (2):
  refs.c: add new functions reflog_exists and delete_reflog
  checkout.c: use ref_exists instead of file_exist

 builtin/checkout.c |  8 ++------
 builtin/reflog.c   |  2 +-
 refs.c             | 21 +++++++++++++++------
 refs.h             |  6 ++++++
 t/t1410-reflog.sh  |  8 ++++++++
 5 files changed, 32 insertions(+), 13 deletions(-)