[PATCH 0/7] midx: ignore cruft pack with `repack`, `expire`

This series fixes a pair of bugs that were originally pointed out by Gregory Szorc in [1].

Namely, that both `git multi-pack-index repack` and `git multi-pack-index expire` can cause us to "absorb" the cruft pack, distributing its objects into a new pack, and removing its metadata.

This is worth avoiding, since even though it doesn't result in object corruption, this bug removes semi-important metadata contained in the .mtimes file, which controls how fast objects leave the repository during a pruning GC.

This series teaches both sub-commands to avoid any cruft pack(s), preserving their metadata.

Thanks in advance for your review.

[1]: https://lore.kernel.org/git/CAKQoGanPBec6wRO6uWrETaoJXdszpjRWytXaJwx6jw0mrrj-gQ@mail.gmail.com/

Taylor Blau (7):
  Documentation/git-multi-pack-index.txt: fix typo
  Documentation/git-multi-pack-index.txt: clarify expire behavior
  midx.c: prevent `expire` from removing the cruft pack
  midx.c: avoid cruft packs with `repack --batch-size=0`
  midx.c: replace `xcalloc()` with `CALLOC_ARRAY()`
  midx.c: remove unnecessary loop condition
  midx.c: avoid cruft packs with non-zero `repack --batch-size`

 Documentation/git-multi-pack-index.txt |  7 +-
 midx.c                                 | 12 +++-
 t/t5319-multi-pack-index.sh            | 94 ++++++++++++++++++++++++++
 3 files changed, 107 insertions(+), 6 deletions(-)