Merge branch 'sp/maint-pack-memuse'

* sp/maint-pack-memuse:
  Correct pack memory leak causing git gc to try to exceed ulimit

Conflicts:

	sha1_file.c

diff --cc sha1_file.c
index 1670e913af0586e4bd3777d8d99952f2b358978e,10346b681e3575d17945f64513e2b0fecbcc01fc..2df78b5afd57cf8e86f01134bf6c49d74defc52a
--- 1/sha1_file.c
--- 2/sha1_file.c
+++ b/sha1_file.c
@@@ -1624,41 -1609,18 +1624,42 @@@ static void *unpack_delta_entry(struct 
        off_t base_offset;
  
        base_offset = get_delta_base(p, w_curs, &curpos, *type, obj_offset);
 +      if (!base_offset) {
 +              error("failed to validate delta base reference "
 +                    "at offset %"PRIuMAX" from %s",
 +                    (uintmax_t)curpos, p->pack_name);
 +              return NULL;
 +      }
+       unuse_pack(w_curs);
        base = cache_or_unpack_entry(p, base_offset, &base_size, type, 0);
 -      if (!base)
 -              die("failed to read delta base object"
 -                  " at %"PRIuMAX" from %s",
 -                  (uintmax_t)base_offset, p->pack_name);
 +      if (!base) {
 +              /*
 +               * We're probably in deep shit, but let's try to fetch
 +               * the required base anyway from another pack or loose.
 +               * This is costly but should happen only in the presence
 +               * of a corrupted pack, and is better than failing outright.
 +               */
 +              struct revindex_entry *revidx = find_pack_revindex(p, base_offset);
 +              const unsigned char *base_sha1 =
 +                                      nth_packed_object_sha1(p, revidx->nr);
 +              error("failed to read delta base object %s"
 +                    " at offset %"PRIuMAX" from %s",
 +                    sha1_to_hex(base_sha1), (uintmax_t)base_offset,
 +                    p->pack_name);
 +              mark_bad_packed_object(p, base_sha1);
 +              base = read_sha1_file(base_sha1, type, &base_size);
 +              if (!base)
 +                      return NULL;
 +      }
  
        delta_data = unpack_compressed_entry(p, w_curs, curpos, delta_size);
 -      if (!delta_data)
 -              die("failed to unpack compressed delta"
 -                  " at %"PRIuMAX" from %s",
 -                  (uintmax_t)curpos, p->pack_name);
 +      if (!delta_data) {
 +              error("failed to unpack compressed delta "
 +                    "at offset %"PRIuMAX" from %s",
 +                    (uintmax_t)curpos, p->pack_name);
 +              free(base);
 +              return NULL;
 +      }
        result = patch_delta(base, base_size,
                             delta_data, delta_size,
                             sizep);