t/helper: stop setting up the_repository repeatedly

The "repository" test helper sets up `the_repository` twice. In fact
though, we don't even have to set it up even once: all we need is to set
up its hash algorithm, because we still depend on some subsystems that
aren't free of `the_repository`.

Refactor the code accordingly. This prepares for a subsequent change,
where setting up the repository repeatedly will lead to a `BUG()`.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

t/helper/test-repository.c

@@ -17,10 +17,6 @@ static void test_parse_commit_in_graph(const char *gitdir, const char *worktree,
 	struct commit *c;
 	struct commit_list *parent;
 
-	setup_git_env(gitdir);
-
-	repo_clear(the_repository);
-
 	if (repo_init(&r, gitdir, worktree))
 		die("Couldn't init repo");
 
@@ -47,10 +43,6 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
 	struct commit *c;
 	struct tree *tree;
 
-	setup_git_env(gitdir);
-
-	repo_clear(the_repository);
-
 	if (repo_init(&r, gitdir, worktree))
 		die("Couldn't init repo");
 
@@ -75,24 +67,20 @@ static void test_get_commit_tree_in_graph(const char *gitdir,
 
 int cmd__repository(int argc, const char **argv)
 {
-	int nongit_ok = 0;
-
-	setup_git_directory_gently(&nongit_ok);
-
 	if (argc < 2)
 		die("must have at least 2 arguments");
 	if (!strcmp(argv[1], "parse_commit_in_graph")) {
 		struct object_id oid;
 		if (argc < 5)
 			die("not enough arguments");
-		if (parse_oid_hex(argv[4], &oid, &argv[4]))
+		if (parse_oid_hex_any(argv[4], &oid, &argv[4]) == GIT_HASH_UNKNOWN)
 			die("cannot parse oid '%s'", argv[4]);
 		test_parse_commit_in_graph(argv[2], argv[3], &oid);
 	} else if (!strcmp(argv[1], "get_commit_tree_in_graph")) {
 		struct object_id oid;
 		if (argc < 5)
 			die("not enough arguments");
-		if (parse_oid_hex(argv[4], &oid, &argv[4]))
+		if (parse_oid_hex_any(argv[4], &oid, &argv[4]) == GIT_HASH_UNKNOWN)
 			die("cannot parse oid '%s'", argv[4]);
 		test_get_commit_tree_in_graph(argv[2], argv[3], &oid);
 	} else {