Merge branch 'jk/startup-info' into maint

The startup_info data, which records if we are working inside a
repository (among other things), are now uniformly available to Git
subcommand implementations, and Git avoids attempting to touch
references when we are not in a repository.

* jk/startup-info:
  use setup_git_directory() in test-* programs
  grep: turn off gitlink detection for --no-index
  mailmap: do not resolve blobs in a non-repository
  remote: don't resolve HEAD in non-repository
  setup: set startup_info->have_repository more reliably
  setup: make startup_info available everywhere

builtin/grep.c

@@ -522,12 +522,14 @@ static int grep_objects(struct grep_opt *opt, const struct pathspec *pathspec,
 }
 
 static int grep_directory(struct grep_opt *opt, const struct pathspec *pathspec,
-			  int exc_std)
+			  int exc_std, int use_index)
 {
 	struct dir_struct dir;
 	int i, hit = 0;
 
 	memset(&dir, 0, sizeof(dir));
+	if (!use_index)
+		dir.flags |= DIR_NO_GITLINKS;
 	if (exc_std)
 		setup_standard_excludes(&dir);
 
@@ -902,7 +904,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 		int use_exclude = (opt_exclude < 0) ? use_index : !!opt_exclude;
 		if (list.nr)
 			die(_("--no-index or --untracked cannot be used with revs."));
-		hit = grep_directory(&opt, &pathspec, use_exclude);
+		hit = grep_directory(&opt, &pathspec, use_exclude, use_index);
 	} else if (0 <= opt_exclude) {
 		die(_("--[no-]exclude-standard cannot be used for tracked contents."));
 	} else if (!list.nr) {

builtin/init-db.c

@@ -322,6 +322,7 @@ int set_git_dir_init(const char *git_dir, const char *real_git_dir,
 		set_git_dir(real_path(git_dir));
 		git_link = NULL;
 	}
+	startup_info->have_repository = 1;
 	return 0;
 }
 

cache.h

@@ -1771,7 +1771,7 @@ int split_cmdline(char *cmdline, const char ***argv);
 /* Takes a negative value returned by split_cmdline */
 const char *split_cmdline_strerror(int cmdline_errno);
 
-/* git.c */
+/* setup.c */
 struct startup_info {
 	int have_repository;
 	const char *prefix;

environment.c

@@ -64,7 +64,6 @@ int grafts_replace_parents = 1;
 int core_apply_sparse_checkout;
 int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
-struct startup_info *startup_info;
 unsigned long pack_size_limit_cfg;
 
 #ifndef PROTECT_HFS_DEFAULT

git.c

@@ -15,7 +15,6 @@ const char git_more_info_string[] =
 	   "concept guides. See 'git help <command>' or 'git help <concept>'\n"
 	   "to read about a specific subcommand or concept.");
 
-static struct startup_info git_startup_info;
 static int use_pager = -1;
 static char *orig_cwd;
 static const char *env_names[] = {
@@ -637,8 +636,6 @@ int main(int argc, char **av)
 	const char *cmd;
 	int done_help = 0;
 
-	startup_info = &git_startup_info;
-
 	cmd = git_extract_argv0_path(argv[0]);
 	if (!cmd)
 		cmd = "git-help";

mailmap.c

@@ -250,7 +250,8 @@ int read_mailmap(struct string_list *map, char **repo_abbrev)
 		git_mailmap_blob = "HEAD:.mailmap";
 
 	err |= read_mailmap_file(map, ".mailmap", repo_abbrev);
-	err |= read_mailmap_blob(map, git_mailmap_blob, repo_abbrev);
+	if (startup_info->have_repository)
+		err |= read_mailmap_blob(map, git_mailmap_blob, repo_abbrev);
 	err |= read_mailmap_file(map, git_mailmap_file, repo_abbrev);
 	return err;
 }

remote.c

@@ -455,7 +455,6 @@ static void read_config(void)
 {
 	static int loaded;
 	struct object_id oid;
-	const char *head_ref;
 	int flag;
 
 	if (loaded)
@@ -463,10 +462,12 @@ static void read_config(void)
 	loaded = 1;
 
 	current_branch = NULL;
-	head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
-	if (head_ref && (flag & REF_ISSYMREF) &&
-	    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
-		current_branch = make_branch(head_ref, 0);
+	if (startup_info->have_repository) {
+		const char *head_ref = resolve_ref_unsafe("HEAD", 0, oid.hash, &flag);
+		if (head_ref && (flag & REF_ISSYMREF) &&
+		    skip_prefix(head_ref, "refs/heads/", &head_ref)) {
+			current_branch = make_branch(head_ref, 0);
+		}
 	}
 	git_config(handle_config, NULL);
 	alias_all_urls();

setup.c

@@ -7,6 +7,9 @@ static int inside_work_tree = -1;
 static int work_tree_config_is_bogus;
 static struct string_list unknown_extensions = STRING_LIST_INIT_DUP;
 
+static struct startup_info the_startup_info;
+struct startup_info *startup_info = &the_startup_info;
+
 /*
  * The input parameter must contain an absolute path, and it must already be
  * normalized.
@@ -905,10 +908,9 @@ const char *setup_git_directory_gently(int *nongit_ok)
 	else
 		setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 
-	if (startup_info) {
-		startup_info->have_repository = !nongit_ok || !*nongit_ok;
-		startup_info->prefix = prefix;
-	}
+	startup_info->have_repository = !nongit_ok || !*nongit_ok;
+	startup_info->prefix = prefix;
+
 	return prefix;
 }
 
@@ -984,7 +986,9 @@ int check_repository_format_version(const char *var, const char *value, void *cb
 
 int check_repository_format(void)
 {
-	return check_repository_format_gently(get_git_dir(), NULL);
+	check_repository_format_gently(get_git_dir(), NULL);
+	startup_info->have_repository = 1;
+	return 0;
 }
 
 /*

sha1_name.c

@@ -1353,9 +1353,6 @@ static char *resolve_relative_path(const char *rel)
 	if (!starts_with(rel, "./") && !starts_with(rel, "../"))
 		return NULL;
 
-	if (!startup_info)
-		die("BUG: startup_info struct is not initialized.");
-
 	if (!is_inside_work_tree())
 		die("relative path syntax can't be used outside working tree.");
 

t/t1506-rev-parse-diagnosis.sh

@@ -166,11 +166,6 @@ test_expect_success 'relative path when cwd is outside worktree' '
 	grep "relative path syntax can.t be used outside working tree." error
 '
 
-test_expect_success 'relative path when startup_info is NULL' '
-	test_must_fail test-match-trees HEAD:./file.txt HEAD:./file.txt 2>error &&
-	grep "BUG: startup_info struct is not initialized." error
-'
-
 test_expect_success '<commit>:file correctly diagnosed after a pathname' '
 	test_must_fail git rev-parse file.txt HEAD:file.txt 1>actual 2>error &&
 	test_i18ngrep ! "exists on disk" error &&

t/t7810-grep.sh

@@ -905,6 +905,33 @@ test_expect_success 'inside git repository but with --no-index' '
 	)
 '
 
+test_expect_success 'grep --no-index descends into repos, but not .git' '
+	rm -fr non &&
+	mkdir -p non/git &&
+	(
+		GIT_CEILING_DIRECTORIES="$(pwd)/non" &&
+		export GIT_CEILING_DIRECTORIES &&
+		cd non/git &&
+
+		echo magic >file &&
+		git init repo &&
+		(
+			cd repo &&
+			echo magic >file &&
+			git add file &&
+			git commit -m foo &&
+			echo magic >.git/file
+		) &&
+
+		cat >expect <<-\EOF &&
+		file
+		repo/file
+		EOF
+		git grep -l --no-index magic >actual &&
+		test_cmp expect actual
+	)
+'
+
 test_expect_success 'setup double-dash tests' '
 cat >double-dash <<EOF &&
 --

test-match-trees.c

@@ -6,6 +6,8 @@ int main(int ac, char **av)
 	unsigned char hash1[20], hash2[20], shifted[20];
 	struct tree *one, *two;
 
+	setup_git_directory();
+
 	if (get_sha1(av[1], hash1))
 		die("cannot parse %s as an object name", av[1]);
 	if (get_sha1(av[2], hash2))

test-revision-walking.c

@@ -50,6 +50,8 @@ int main(int argc, char **argv)
 	if (argc < 2)
 		return 1;
 
+	setup_git_directory();
+
 	if (!strcmp(argv[1], "run-twice")) {
 		printf("1st\n");
 		if (!run_revision_walk())