[PATCH 1/2] repack: teach --no-prune-packed to skip `git prune-packed`

[Rafael Silva <rafaeloliveira.cs@gmail.com>]

The `git repack -d` command will remove any packfile that becomes
redundant after repacking, and then call  `git pruned-packed` for
pruning any unpacked objects. The command, however, does not offer
an option to skip the `pruned-packed` execution in order to allow
inspecting the objects before they are removed, forcing developers
to either make some temporary code changes or to manually craft
the `pack-objects` command in order to skip their deletion:

    git pack-objects --honor-pack-keep --non-empty --all --reflog \
    	--unpack-unreachable

Let’s teach `repack -d` to take --no-pruned-packed option that will
simply skip the call to `git prune-packed`, thus providing an easy
way to debug the `repack` command. This also allows us to simplify
our test suite by replacing calls to `pack-objects` with `repack`:

    git repack -A -d --no-prune-packed

Moreover, using the repack command will actually test its code path
instead of just testing the real repack operation by calling
`git pack-objects` directly. Let's refactor two tests in t7700 with
the new option.

Aside from improving our test suite, this new option will be used in
an upcoming commit for testing the behavior of `repack` with partial
clone repositories.

Signed-off-by: Rafael Silva <rafaeloliveira.cs@gmail.com>
---
 Documentation/git-repack.txt |  5 +++++
 builtin/repack.c             |  6 +++++-
 t/t7700-repack.sh            | 23 +++++++++++------------
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/Documentation/git-repack.txt b/Documentation/git-repack.txt
index 317d63cf0d..6ff7a1be16 100644
--- a/Documentation/git-repack.txt
+++ b/Documentation/git-repack.txt
@@ -86,6 +86,11 @@ to the new separate pack will be written.
 	this repository (or a direct copy of it)
 	over HTTP or FTP.  See linkgit:git-update-server-info[1].
 
+--no-prune-packed::
+	Only useful with `-d`.  Do not remove redundant loose object
+	files by skipping the execution of `git prune-packed`.
+	See linkgit:git-prune-packed[1].
+
 --window=<n>::
 --depth=<n>::
 	These two options affect how the objects contained in the pack are
diff --git a/builtin/repack.c b/builtin/repack.c
index 2847fdfbab..6baaeb979c 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -452,6 +452,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	int keep_unreachable = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
 	int no_update_server_info = 0;
+	int no_prune_packed = 0;
 	struct pack_objects_args po_args = {NULL};
 	int geometric_factor = 0;
 
@@ -469,6 +470,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				N_("pass --no-reuse-object to git-pack-objects")),
 		OPT_BOOL('n', NULL, &no_update_server_info,
 				N_("do not run git-update-server-info")),
+		OPT_BOOL(0, "no-prune-packed", &no_prune_packed,
+				N_("do not run git-prune-packed")),
 		OPT__QUIET(&po_args.quiet, N_("be quiet")),
 		OPT_BOOL('l', "local", &po_args.local,
 				N_("pass --local to git-pack-objects")),
@@ -707,7 +710,8 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		}
 		if (!po_args.quiet && isatty(2))
 			opts |= PRUNE_PACKED_VERBOSE;
-		prune_packed_objects(opts);
+		if (!no_prune_packed)
+			prune_packed_objects(opts);
 
 		if (!keep_unreachable &&
 		    (!(pack_everything & LOOSEN_UNREACHABLE) ||
diff --git a/t/t7700-repack.sh b/t/t7700-repack.sh
index 25b235c063..728a16ad97 100755
--- a/t/t7700-repack.sh
+++ b/t/t7700-repack.sh
@@ -127,12 +127,7 @@ test_expect_success 'packed unreachable obs in alternate ODB are not loosened' '
 	git reset --hard HEAD^ &&
 	test_tick &&
 	git reflog expire --expire=$test_tick --expire-unreachable=$test_tick --all &&
-	# The pack-objects call on the next line is equivalent to
-	# git repack -A -d without the call to prune-packed
-	git pack-objects --honor-pack-keep --non-empty --all --reflog \
-	    --unpack-unreachable </dev/null pack &&
-	rm -f .git/objects/pack/* &&
-	mv pack-* .git/objects/pack/ &&
+	git repack -A -d --no-prune-packed &&
 	git verify-pack -v -- .git/objects/pack/*.idx >packlist &&
 	! grep "^$coid " packlist &&
 	echo >.git/objects/info/alternates &&
@@ -144,18 +139,22 @@ test_expect_success 'local packed unreachable obs that exist in alternate ODB ar
 	echo "$coid" | git pack-objects --non-empty --all --reflog pack &&
 	rm -f .git/objects/pack/* &&
 	mv pack-* .git/objects/pack/ &&
-	# The pack-objects call on the next line is equivalent to
-	# git repack -A -d without the call to prune-packed
-	git pack-objects --honor-pack-keep --non-empty --all --reflog \
-	    --unpack-unreachable </dev/null pack &&
-	rm -f .git/objects/pack/* &&
-	mv pack-* .git/objects/pack/ &&
+	git repack -A -d --no-prune-packed &&
 	git verify-pack -v -- .git/objects/pack/*.idx >packlist &&
 	! grep "^$coid " &&
 	echo >.git/objects/info/alternates &&
 	test_must_fail git show $coid
 '
 
+test_expect_success '-A -d and --no-prune-packed do not remove loose objects' '
+	test_create_repo repo &&
+	test_when_finished "rm -rf repo" &&
+	test_commit -C repo commit &&
+	git -C repo repack -A -d --no-prune-packed &&
+	git -C repo count-objects -v >out &&
+	grep "^prune-packable: 3" out
+'
+
 test_expect_success 'objects made unreachable by grafts only are kept' '
 	test_tick &&
 	git commit --allow-empty -m "commit 4" &&
-- 
2.31.0.565.gcc42f43761