builtin/repack.c: remove redundant pack-based bitmaps

When we write a MIDX bitmap after repacking, it is possible that the
repository would be left in a state with both pack- and multi-pack
reachability bitmaps.

This can occur, for instance, if a pack that was kept (either by having
a .keep file, or during a geometric repack in which it is not rolled up)
has a bitmap file, and the repack wrote a multi-pack index and bitmap.

When loading a reachability bitmap for the repository, the multi-pack
one is always preferred, so the pack-based one is redundant. Let's
remove it unconditionally, even if '-d' isn't passed, since there is no
practical reason to keep both around. The patch below does just that.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/t/t7700-repack.sh b/t/t7700-repack.sh
index ca45c4cd2c..2d0e9448dd 100755
--- a/t/t7700-repack.sh
+++ b/t/t7700-repack.sh
@@ -426,6 +426,27 @@ test_expect_success '--write-midx -b packs non-kept objects' '
 	)
 '
 
+test_expect_success '--write-midx removes stale pack-based bitmaps' '
+       rm -fr repo &&
+       git init repo &&
+       test_when_finished "rm -fr repo" &&
+       (
+		cd repo &&
+		test_commit base &&
+		GIT_TEST_MULTI_PACK_INDEX=0 git repack -Ab &&
+
+		pack_bitmap=$(ls $objdir/pack/pack-*.bitmap) &&
+		test_path_is_file "$pack_bitmap" &&
+
+		test_commit tip &&
+		GIT_TEST_MULTI_PACK_INDEX=0 git repack -bm &&
+
+		test_path_is_file $midx &&
+		test_path_is_file $midx-$(midx_checksum $objdir).bitmap &&
+		test_path_is_missing $pack_bitmap
+       )
+'
+
 test_expect_success TTY '--quiet disables progress' '
 	test_terminal env GIT_PROGRESS_DELAY=0 \
 		git -C midx repack -ad --quiet --write-midx 2>stderr &&