Merge branch 'tb/stdin-packs-excluded-but-open'

pack-objects's --stdin-packs=follow mode learns to handle
excluded-but-open packs.

* tb/stdin-packs-excluded-but-open:
  repack: mark non-MIDX packs above the split as excluded-open
  pack-objects: support excluded-open packs with --stdin-packs
  t7704: demonstrate failure with once-cruft objects above the geometric split
  pack-objects: refactor `read_packs_list_from_stdin()` to use `strmap`
  pack-objects: plug leak in `read_stdin_packs()`

diff --cc builtin/pack-objects.c
Simple merge

diff --cc packfile.c
Simple merge

diff --cc packfile.h
index 45b35973f07b370d8e51bdf500bca91fca8bed38,b7735c1977d8a56cb2a2ad2be85a2878ffa56d6a..6e8802e2ed448732a498980bd0f93f61af438c74
--- 1/packfile.h
--- 2/packfile.h
+++ b/packfile.h
@@@ -266,18 -267,9 +267,19 @@@ int packfile_store_freshen_object(struc
  enum kept_pack_type {
        KEPT_PACK_ON_DISK = (1 << 0),
        KEPT_PACK_IN_CORE = (1 << 1),
+       KEPT_PACK_IN_CORE_OPEN = (1 << 2),
  };
  
 +/*
 + * Count the number objects contained in the given packfile store. If
 + * successful, the number of objects will be written to the `out` pointer.
 + *
 + * Return 0 on success, a negative error code otherwise.
 + */
 +int packfile_store_count_objects(struct packfile_store *store,
 +                               enum odb_count_objects_flags flags,
 +                               unsigned long *out);
 +
  /*
   * Retrieve the cache of kept packs from the given packfile store. Accepts a
   * combination of `kept_pack_type` flags. The cache is computed on demand and