Merge branch 'tb/repack-cleanup'

The recent change to "git repack" made it react less nicely when a
leftover .idx file that no longer has the corresponding .pack file
in the repository, which has been corrected.

* tb/repack-cleanup:
  builtin/repack.c: avoid dir traversal in `collect_pack_filenames()`
  builtin/repack.c: only repack `.pack`s that exist

Author: gitster

builtin/repack.c

@@ -105,46 +105,38 @@ static void collect_pack_filenames(struct string_list *fname_nonkept_list,
 				   struct string_list *fname_kept_list,
 				   const struct string_list *extra_keep)
 {
-	DIR *dir;
-	struct dirent *e;
-	char *fname;
+	struct packed_git *p;
 	struct strbuf buf = STRBUF_INIT;
 
-	if (!(dir = opendir(packdir)))
-		return;
-
-	while ((e = readdir(dir)) != NULL) {
-		size_t len;
+	for (p = get_all_packs(the_repository); p; p = p->next) {
 		int i;
+		const char *base;
 
-		if (!strip_suffix(e->d_name, ".idx", &len))
+		if (!p->pack_local)
 			continue;
 
-		strbuf_reset(&buf);
-		strbuf_add(&buf, e->d_name, len);
-		strbuf_addstr(&buf, ".pack");
+		base = pack_basename(p);
 
 		for (i = 0; i < extra_keep->nr; i++)
-			if (!fspathcmp(buf.buf, extra_keep->items[i].string))
+			if (!fspathcmp(base, extra_keep->items[i].string))
 				break;
 
-		fname = xmemdupz(e->d_name, len);
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, base);
+		strbuf_strip_suffix(&buf, ".pack");
 
-		if ((extra_keep->nr > 0 && i < extra_keep->nr) ||
-		    (file_exists(mkpath("%s/%s.keep", packdir, fname)))) {
-			string_list_append_nodup(fname_kept_list, fname);
-		} else {
+		if ((extra_keep->nr > 0 && i < extra_keep->nr) || p->pack_keep)
+			string_list_append(fname_kept_list, buf.buf);
+		else {
 			struct string_list_item *item;
-			item = string_list_append_nodup(fname_nonkept_list,
-							fname);
-			if (file_exists(mkpath("%s/%s.mtimes", packdir, fname)))
+			item = string_list_append(fname_nonkept_list, buf.buf);
+			if (p->is_cruft)
 				item->util = (void*)(uintptr_t)CRUFT_PACK;
 		}
 	}
-	closedir(dir);
-	strbuf_release(&buf);
 
 	string_list_sort(fname_kept_list);
+	strbuf_release(&buf);
 }
 
 static void remove_redundant_pack(const char *dir_name, const char *base_name)

t/t7700-repack.sh

@@ -213,7 +213,7 @@ test_expect_success 'repack --keep-pack' '
 	test_create_repo keep-pack &&
 	(
 		cd keep-pack &&
-		# avoid producing difference packs to delta/base choices
+		# avoid producing different packs due to delta/base choices
 		git config pack.window 0 &&
 		P1=$(commit_and_pack 1) &&
 		P2=$(commit_and_pack 2) &&
@@ -239,6 +239,10 @@ test_expect_success 'repack --keep-pack' '
 			mv "$from" "$to" || return 1
 		done &&
 
+		# A .idx file without a .pack should not stop us from
+		# repacking what we can.
+		touch .git/objects/pack/pack-does-not-exist.idx &&
+
 		git repack --cruft -d --keep-pack $P1 --keep-pack $P4 &&
 
 		ls .git/objects/pack/*.pack >newer-counts &&
@@ -247,6 +251,36 @@ test_expect_success 'repack --keep-pack' '
 	)
 '
 
+test_expect_success 'repacking fails when missing .pack actually means missing objects' '
+	test_create_repo idx-without-pack &&
+	(
+		cd idx-without-pack &&
+
+		# Avoid producing different packs due to delta/base choices
+		git config pack.window 0 &&
+		P1=$(commit_and_pack 1) &&
+		P2=$(commit_and_pack 2) &&
+		P3=$(commit_and_pack 3) &&
+		P4=$(commit_and_pack 4) &&
+		ls .git/objects/pack/*.pack >old-counts &&
+		test_line_count = 4 old-counts &&
+
+		# Remove one .pack file
+		rm .git/objects/pack/$P2 &&
+
+		ls .git/objects/pack/*.pack >before-pack-dir &&
+
+		test_must_fail git fsck &&
+		test_must_fail git repack --cruft -d 2>err &&
+		grep "bad object" err &&
+
+		# Before failing, the repack did not modify the
+		# pack directory.
+		ls .git/objects/pack/*.pack >after-pack-dir &&
+		test_cmp before-pack-dir after-pack-dir
+	)
+'
+
 test_expect_success 'bitmaps are created by default in bare repos' '
 	git clone --bare .git bare.git &&
 	rm -f bare.git/objects/pack/*.bitmap &&