Subject: [PATCH v2 24/24] midx: clear midx on repack

From: Derrick Stolee <[email-masked]>
Date: Mon, 25 Jun 2018 10:34:34 -0400

If a 'git repack' command replaces existing packfiles, then we must
clear the existing multi-pack-index before moving the packfiles it
references.

Signed-off-by: Derrick Stolee <[email-masked]>
---
 builtin/repack.c | 8 ++++++++
 midx.c           | 8 ++++++++
 midx.h           | 1 +
 3 files changed, 17 insertions(+)

diff --git a/builtin/repack.c b/builtin/repack.c
index 6c636e159e..66a7d8e8ea 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -8,6 +8,7 @@
 #include "strbuf.h"
 #include "string-list.h"
 #include "argv-array.h"
+#include "midx.h"
 
 static int delta_base_offset = 1;
 static int pack_kept_objects = -1;
@@ -174,6 +175,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	int no_update_server_info = 0;
 	int quiet = 0;
 	int local = 0;
+	int midx_cleared = 0;
 
 	struct option builtin_repack_options[] = {
 		OPT_BIT('a', NULL, &pack_everything,
@@ -340,6 +342,12 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				continue;
 			}
 
+			if (!midx_cleared) {
+				/* if we move a packfile, it will invalidated the midx */
+				clear_midx_file(get_object_directory());
+				midx_cleared = 1;
+			}
+
 			fname_old = mkpathdup("%s/old-%s%s", packdir,
 						item->string, exts[ext].name);
 			if (file_exists(fname_old))
diff --git a/midx.c b/midx.c
index 02cbfc5bd5..ef9fb38610 100644
--- a/midx.c
+++ b/midx.c
@@ -890,3 +890,11 @@ int write_midx_file(const char *object_dir)
 	FREE_AND_NULL(pack_perm);
 	return 0;
 }
+
+void clear_midx_file(const char *object_dir)
+{
+	char *midx = get_midx_filename(object_dir);
+
+	if (remove_path(midx))
+		die(_("failed to clear multi-pack-index at %s"), midx);
+}
diff --git a/midx.h b/midx.h
index 5faffb7bc6..5a42cbed1d 100644
--- a/midx.h
+++ b/midx.h
@@ -15,5 +15,6 @@ int midx_contains_pack(struct multi_pack_index *m, const char *idx_name);
 int prepare_multi_pack_index_one(struct repository *r, const char *object_dir);
 
 int write_midx_file(const char *object_dir);
+void clear_midx_file(const char *object_dir);
 
 #endif
-- 
2.18.0.24.g1b579a2ee9