Re: [PATCH 2/5] pack-bitmap: tag bitmapped packs with their corresponding MIDX

The next commit will need to use the bitmap's MIDX (if one exists) to
translate bit positions into pack-relative positions in the source pack.

Ordinarily, we'd use the "midx" field of the bitmap_index struct. But
since that struct is defined within pack-bitmap.c, and our caller is in
a separate compilation unit, we do not have access to the MIDX field.

Instead, add a "from_midx" field to the bitmapped_pack structure so that
we can use that piece of data from outside of pack-bitmap.c. The caller
that uses this new piece of information will be added in the following
commit.

Signed-off-by: Taylor Blau <redacted>
---
 midx.c        | 1 +
 pack-bitmap.c | 1 +
 pack-bitmap.h | 1 +
 3 files changed, 3 insertions(+)

diff --git a/midx.c b/midx.c
index ca98bfd7c6..67e0d64004 100644
--- a/midx.c
+++ b/midx.c

@@ -496,6 +496,7 @@ int nth_bitmapped_pack(struct repository *r, struct multi_pack_index *m,
 				 MIDX_CHUNK_BITMAPPED_PACKS_WIDTH * local_pack_int_id +
 				 sizeof(uint32_t));
 	bp->pack_int_id = pack_int_id;
+	bp->from_midx = m;