[PATCH 0/6] Yet another approach to handling empty snapshots

This patch series fixes the handling of empty packed-refs snapshots (i.e., those with `snapshot->buf` and friends equal to `NULL`), partly by changing `snapshot` to store a pointer to the start of the post-header `packed-refs` content instead of `header_len`. It makes a couple of other improvements as well.

I'm not sure whether I like this approach better than the alternative of always setting `snapshot->buf` to a non-NULL value, by allocating a length-1 bit of RAM if necessary. The latter is less intrusive, though even if that approach is taken, I think patches 01, 02, and 04 from this patch series would be worthwhile improvements.

Michael

Kim Gybels (1):
  packed_ref_cache: don't use mmap() for small files

Michael Haggerty (5):
  struct snapshot: store `start` rather than `header_len`
  create_snapshot(): use `xmemdupz()` rather than a strbuf
  find_reference_location(): make function safe for empty snapshots
  packed_ref_iterator_begin(): make optimization more general
  load_contents(): don't try to mmap an empty file

 refs/packed-backend.c | 106 ++++++++++++++++++++++++++------------------------
 1 file changed, 55 insertions(+), 51 deletions(-)