From 31d10704d4d458e89de371e5a7f13932f54beb7d Mon Sep 17 00:00:00 2001
From: Patrick Steinhardt <ps@pks.im>
Date: Mon, 31 Aug 2026 08:46:23 +0200
Subject: [PATCH] builtin/fsck: move multi-pack index verification into the
 packed source

The checks for multi-pack indexes are hosted in `cmd_fsck()` directly.
These checks are obviously specific to the "packed" backend.

Move the logic into `odb_source_packed_fsck()`. As in preceding commits,
this means that we now properly honor both "--connectivity-only" and
"--no-full". Furthermore, we drop the dedicated `ERROR_MULTI_PACK_INDEX`
bit and instead use the generic `ERROR_OBJECT` bit.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 builtin/fsck.c              | 18 ------------------
 odb/source-packed.c         | 27 +++++++++++++++++++++++++++
 t/t5319-multi-pack-index.sh | 13 +++++++++++++
 3 files changed, 40 insertions(+), 18 deletions(-)

diff --git a/builtin/fsck.c b/builtin/fsck.c
index 2f7d29aa56..7eaea340b0 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -48,7 +48,6 @@ static timestamp_t now;
 #define ERROR_REACHABLE 02
 #define ERROR_REFS 010
 #define ERROR_COMMIT_GRAPH 020
-#define ERROR_MULTI_PACK_INDEX 040
 
 static const char *describe_object(const struct object_id *oid)
 {
@@ -1085,23 +1084,6 @@ int cmd_fsck(int argc,
 		}
 	}
 
-	if (repo->settings.core_multi_pack_index) {
-		struct child_process midx_verify = CHILD_PROCESS_INIT;
-
-		for (source = repo->objects->sources; source; source = source->next) {
-			child_process_init(&midx_verify);
-			midx_verify.git_cmd = 1;
-			strvec_pushl(&midx_verify.args, "multi-pack-index",
-				     "verify", "--object-dir", source->path, NULL);
-			if (show_progress)
-				strvec_push(&midx_verify.args, "--progress");
-			else
-				strvec_push(&midx_verify.args, "--no-progress");
-			if (run_command(&midx_verify))
-				errors_found |= ERROR_MULTI_PACK_INDEX;
-		}
-	}
-
 	free_snapshot_refs(&snap);
 	return errors_found;
 }
diff --git a/odb/source-packed.c b/odb/source-packed.c
index 2b5dc502f5..9f42552377 100644
--- a/odb/source-packed.c
+++ b/odb/source-packed.c
@@ -14,6 +14,7 @@
 #include "packfile.h"
 #include "pack-bitmap.h"
 #include "progress.h"
+#include "run-command.h"
 
 static int find_pack_entry(struct odb_source_packed *store,
 			   const struct object_id *oid,
@@ -897,6 +898,29 @@ static int verify_reverse_indices(struct odb_source_packed *source,
 	return res;
 }
 
+static int verify_midx(struct odb_source_packed *source,
+		       struct odb_fsck_options *opts)
+{
+	struct child_process midx_verify = CHILD_PROCESS_INIT;
+	int ret = 0;
+
+	if (!source->base.odb->repo->settings.core_multi_pack_index)
+		return 0;
+
+	child_process_init(&midx_verify);
+	midx_verify.git_cmd = 1;
+	strvec_pushl(&midx_verify.args, "multi-pack-index",
+		     "verify", "--object-dir", source->base.path, NULL);
+	if (opts->flags & ODB_FSCK_PROGRESS)
+		strvec_push(&midx_verify.args, "--progress");
+	else
+		strvec_push(&midx_verify.args, "--no-progress");
+	if (run_command(&midx_verify))
+		ret = -1;
+
+	return ret;
+}
+
 static int odb_source_packed_fsck(struct odb_source *source,
 				  struct odb_fsck_options *opts)
 {
@@ -912,6 +936,9 @@ static int odb_source_packed_fsck(struct odb_source *source,
 	if (verify_bitmap_files(packed))
 		ret = -1;
 
+	if (verify_midx(packed, opts) < 0)
+		ret = -1;
+
 	return ret;
 }
 
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 68143cb5b7..20b010c33b 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -573,6 +573,19 @@ test_expect_success 'verify incorrect checksum' '
 		$objdir "incorrect checksum"
 '
 
+test_expect_success 'git fsck --no-full checks multi-pack-index, --connectivity-only does not' '
+	pos=$(($(wc -c <$objdir/pack/multi-pack-index) - 10)) &&
+	corrupt_midx_and_verify $pos \
+		"\377\377\377\377\377\377\377\377\377\377" \
+		$objdir "incorrect checksum" &&
+
+	test_must_fail git fsck --no-full 2>err &&
+	test_grep "incorrect checksum" err &&
+
+	git fsck --connectivity-only 2>err &&
+	test_grep ! "incorrect checksum" err
+'
+
 test_expect_success 'setup for v1-specific fsck tests' '
 	git -c midx.version=1 multi-pack-index write
 '