environment: make `get_git_dir()` accept a repository

The `get_git_dir()` function retrieves the path to the Git directory for
`the_repository`. Make it accept a `struct repository` such that it can
work on arbitrary repositories and make it part of the repository
subsystem. This reduces our reliance on `the_repository` and clarifies
scope.

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

21 files changed, 56 insertions, 38 deletions

diff --git a/apply.c b/apply.c
index 6e1060a952..426cec32f8 100644
--- a/apply.c
+++ b/apply.c
@@ -30,6 +30,7 @@
 #include "path.h"
 #include "quote.h"
 #include "read-cache.h"
+#include "repository.h"
 #include "rerere.h"
 #include "apply.h"
 #include "entry.h"
@@ -4111,7 +4112,7 @@ static int read_apply_cache(struct apply_state *state)
 {
 	if (state->index_file)
 		return read_index_from(state->repo->index, state->index_file,
-				       get_git_dir());
+				       repo_get_git_dir(the_repository));
 	else
 		return repo_read_index(state->repo);
 }
diff --git a/builtin/am.c b/builtin/am.c
index d8875ad402..405214e242 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1544,7 +1544,8 @@ static int run_apply(const struct am_state *state, const char *index_file)
 	if (index_file) {
 		/* Reload index as apply_all_patches() will have modified it. */
 		discard_index(the_repository->index);
-		read_index_from(the_repository->index, index_file, get_git_dir());
+		read_index_from(the_repository->index, index_file,
+				repo_get_git_dir(the_repository));
 	}
 
 	return 0;
@@ -1587,7 +1588,7 @@ static int fall_back_threeway(const struct am_state *state, const char *index_pa
 		return error("could not build fake ancestor");
 
 	discard_index(the_repository->index);
-	read_index_from(the_repository->index, index_path, get_git_dir());
+	read_index_from(the_repository->index, index_path, repo_get_git_dir(the_repository));
 
 	if (write_index_as_tree(&bases[0], the_repository->index, index_path, 0, NULL))
 		return error(_("Repository lacks necessary blobs to fall back on 3-way merge."));
diff --git a/builtin/commit.c b/builtin/commit.c
index b2033c4887..a1c1d16a09 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -26,6 +26,7 @@
 #include "path.h"
 #include "preload-index.h"
 #include "read-cache.h"
+#include "repository.h"
 #include "string-list.h"
 #include "rerere.h"
 #include "unpack-trees.h"
@@ -407,7 +408,7 @@ static const char *prepare_index(const char **argv, const char *prefix,
 
 		discard_index(the_repository->index);
 		read_index_from(the_repository->index, get_lock_file_path(&index_lock),
-				get_git_dir());
+				repo_get_git_dir(the_repository));
 		if (cache_tree_update(the_repository->index, WRITE_TREE_SILENT) == 0) {
 			if (reopen_lock_file(&index_lock) < 0)
 				die(_("unable to write index file"));
@@ -534,7 +535,7 @@ static const char *prepare_index(const char **argv, const char *prefix,
 
 	discard_index(the_repository->index);
 	ret = get_lock_file_path(&false_lock);
-	read_index_from(the_repository->index, ret, get_git_dir());
+	read_index_from(the_repository->index, ret, repo_get_git_dir(the_repository));
 out:
 	string_list_clear(&partial, 0);
 	clear_pathspec(&pathspec);
@@ -1072,7 +1073,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 		 */
 		discard_index(the_repository->index);
 	}
-	read_index_from(the_repository->index, index_file, get_git_dir());
+	read_index_from(the_repository->index, index_file, repo_get_git_dir(the_repository));
 
 	if (cache_tree_update(the_repository->index, 0)) {
 		error(_("Error building trees"));
diff --git a/builtin/config.c b/builtin/config.c
index e00d983596..c10697a2ef 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -808,7 +808,7 @@ static void location_options_init(struct config_location_options *opts,
 		opts->options.respect_includes = opts->respect_includes_opt;
 	if (startup_info->have_repository) {
 		opts->options.commondir = get_git_common_dir();
-		opts->options.git_dir = get_git_dir();
+		opts->options.git_dir = repo_get_git_dir(the_repository);
 	}
 }
 
diff --git a/builtin/difftool.c b/builtin/difftool.c
index dcc68e190c..8c59411e6e 100644
--- a/builtin/difftool.c
+++ b/builtin/difftool.c
@@ -22,6 +22,7 @@
 #include "hex.h"
 #include "parse-options.h"
 #include "read-cache-ll.h"
+#include "repository.h"
 #include "sparse-index.h"
 #include "strvec.h"
 #include "strbuf.h"
@@ -214,7 +215,7 @@ static void changed_files(struct hashmap *result, const char *index_path,
 	struct child_process update_index = CHILD_PROCESS_INIT;
 	struct child_process diff_files = CHILD_PROCESS_INIT;
 	struct strbuf buf = STRBUF_INIT;
-	const char *git_dir = absolute_path(get_git_dir());
+	const char *git_dir = absolute_path(repo_get_git_dir(the_repository));
 	FILE *fp;
 
 	strvec_pushl(&update_index.args,
@@ -737,7 +738,7 @@ int cmd_difftool(int argc, const char **argv, const char *prefix)
 
 	if (!no_index){
 		setup_work_tree();
-		setenv(GIT_DIR_ENVIRONMENT, absolute_path(get_git_dir()), 1);
+		setenv(GIT_DIR_ENVIRONMENT, absolute_path(repo_get_git_dir(the_repository)), 1);
 		setenv(GIT_WORK_TREE_ENVIRONMENT, absolute_path(get_git_work_tree()), 1);
 	} else if (dir_diff)
 		die(_("options '%s' and '%s' cannot be used together"), "--dir-diff", "--no-index");
diff --git a/builtin/fsmonitor--daemon.c b/builtin/fsmonitor--daemon.c
index 1593713f4c..c54e736716 100644
--- a/builtin/fsmonitor--daemon.c
+++ b/builtin/fsmonitor--daemon.c
@@ -1311,7 +1311,8 @@ static int fsmonitor_run_daemon(void)
 	strbuf_addstr(&state.path_gitdir_watch, "/.git");
 	if (!is_directory(state.path_gitdir_watch.buf)) {
 		strbuf_reset(&state.path_gitdir_watch);
-		strbuf_addstr(&state.path_gitdir_watch, absolute_path(get_git_dir()));
+		strbuf_addstr(&state.path_gitdir_watch,
+			      absolute_path(repo_get_git_dir(the_repository)));
 		state.nr_paths_watching = 2;
 	}
 
diff --git a/builtin/merge.c b/builtin/merge.c
index 662a49a0e8..a2bae0700b 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -17,6 +17,7 @@
 #include "object-name.h"
 #include "parse-options.h"
 #include "lockfile.h"
+#include "repository.h"
 #include "run-command.h"
 #include "hook.h"
 #include "diff.h"
@@ -855,7 +856,8 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 		if (invoked_hook)
 			discard_index(the_repository->index);
 	}
-	read_index_from(the_repository->index, index_file, get_git_dir());
+	read_index_from(the_repository->index, index_file,
+			repo_get_git_dir(the_repository));
 	strbuf_addbuf(&msg, &merge_msg);
 	if (squash)
 		BUG("the control must not reach here under --squash");
diff --git a/builtin/stash.c b/builtin/stash.c
index fcfd97972a..ad6bcefb77 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -19,6 +19,7 @@
 #include "entry.h"
 #include "preload-index.h"
 #include "read-cache.h"
+#include "repository.h"
 #include "rerere.h"
 #include "revision.h"
 #include "setup.h"
@@ -642,7 +643,7 @@ restore_untracked:
 		strvec_pushf(&cp.env, GIT_WORK_TREE_ENVIRONMENT"=%s",
 			     absolute_path(get_git_work_tree()));
 		strvec_pushf(&cp.env, GIT_DIR_ENVIRONMENT"=%s",
-			     absolute_path(get_git_dir()));
+			     absolute_path(repo_get_git_dir(the_repository)));
 		strvec_push(&cp.args, "status");
 		run_command(&cp);
 	}
diff --git a/cache-tree.c b/cache-tree.c
index 50610c3f3c..b482167a69 100644
--- a/cache-tree.c
+++ b/cache-tree.c
@@ -1,7 +1,6 @@
 #define USE_THE_REPOSITORY_VARIABLE
 
 #include "git-compat-util.h"
-#include "environment.h"
 #include "hex.h"
 #include "lockfile.h"
 #include "tree.h"
@@ -12,6 +11,7 @@
 #include "object-store-ll.h"
 #include "read-cache-ll.h"
 #include "replace-object.h"
+#include "repository.h"
 #include "promisor-remote.h"
 #include "trace.h"
 #include "trace2.h"
@@ -725,7 +725,8 @@ int write_index_as_tree(struct object_id *oid, struct index_state *index_state,
 
 	hold_lock_file_for_update(&lock_file, index_path, LOCK_DIE_ON_ERROR);
 
-	entries = read_index_from(index_state, index_path, get_git_dir());
+	entries = read_index_from(index_state, index_path,
+				  repo_get_git_dir(the_repository));
 	if (entries < 0) {
 		ret = WRITE_TREE_UNREADABLE_INDEX;
 		goto out;
diff --git a/config.c b/config.c
index 56b5862e59..1733ba85dc 100644
--- a/config.c
+++ b/config.c
@@ -6,6 +6,8 @@
  *
  */
 
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "git-compat-util.h"
 #include "abspath.h"
 #include "advice.h"
@@ -2212,7 +2214,7 @@ void read_early_config(config_fn_t cb, void *data)
 
 	if (have_git_dir()) {
 		opts.commondir = get_git_common_dir();
-		opts.git_dir = get_git_dir();
+		opts.git_dir = repo_get_git_dir(the_repository);
 	/*
 	 * When setup_git_directory() was not yet asked to discover the
 	 * GIT_DIR, we ask discover_git_directory() to figure out whether there
diff --git a/environment.c b/environment.c
index 1d6c48b52d..040b1ff1ba 100644
--- a/environment.c
+++ b/environment.c
@@ -228,13 +228,6 @@ int have_git_dir(void)
 		|| the_repository->gitdir;
 }
 
-const char *get_git_dir(void)
-{
-	if (!the_repository->gitdir)
-		BUG("git environment hasn't been setup");
-	return the_repository->gitdir;
-}
-
 const char *get_git_common_dir(void)
 {
 	if (!the_repository->commondir)
@@ -352,7 +345,8 @@ static void update_relative_gitdir(const char *name UNUSED,
 				   const char *new_cwd,
 				   void *data UNUSED)
 {
-	char *path = reparent_relative_path(old_cwd, new_cwd, get_git_dir());
+	char *path = reparent_relative_path(old_cwd, new_cwd,
+					    repo_get_git_dir(the_repository));
 	struct tmp_objdir *tmp_objdir = tmp_objdir_unapply_primary_odb();
 
 	trace_printf_key(&trace_setup_key,
diff --git a/environment.h b/environment.h
index 0148738ed6..06d37d5c82 100644
--- a/environment.h
+++ b/environment.h
@@ -106,7 +106,6 @@ int have_git_dir(void);
 extern int is_bare_repository_cfg;
 int is_bare_repository(void);
 extern char *git_work_tree_cfg;
-const char *get_git_dir(void);
 const char *get_git_common_dir(void);
 const char *get_object_directory(void);
 char *get_index_file(void);
diff --git a/pathspec.c b/pathspec.c
index fe1f0f41af..416fe1e3dc 100644
--- a/pathspec.c
+++ b/pathspec.c
@@ -497,7 +497,7 @@ static void init_pathspec_item(struct pathspec_item *item, unsigned flags,
 				    copyfrom);
 			hint_path = get_git_work_tree();
 			if (!hint_path)
-				hint_path = get_git_dir();
+				hint_path = repo_get_git_dir(the_repository);
 			die(_("%s: '%s' is outside repository at '%s'"), elt,
 			    copyfrom, absolute_path(hint_path));
 		}
diff --git a/read-cache.c b/read-cache.c
index 4e67dc182e..764fdfec46 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -31,6 +31,7 @@
 #include "path.h"
 #include "preload-index.h"
 #include "read-cache.h"
+#include "repository.h"
 #include "resolve-undo.h"
 #include "revision.h"
 #include "strbuf.h"
@@ -3238,10 +3239,11 @@ static int should_delete_shared_index(const char *shared_index_path)
 static int clean_shared_index_files(const char *current_hex)
 {
 	struct dirent *de;
-	DIR *dir = opendir(get_git_dir());
+	DIR *dir = opendir(repo_get_git_dir(the_repository));
 
 	if (!dir)
-		return error_errno(_("unable to open git dir: %s"), get_git_dir());
+		return error_errno(_("unable to open git dir: %s"),
+				   repo_get_git_dir(the_repository));
 
 	while ((de = readdir(dir)) != NULL) {
 		const char *sha1_hex;
diff --git a/repository.c b/repository.c
index 9825a30899..31afc62551 100644
--- a/repository.c
+++ b/repository.c
@@ -91,6 +91,13 @@ static void expand_base_dir(char **out, const char *in,
 		*out = xstrfmt("%s/%s", base_dir, def_in);
 }
 
+const char *repo_get_git_dir(struct repository *repo)
+{
+	if (!repo->gitdir)
+		BUG("repository hasn't been set up");
+	return repo->gitdir;
+}
+
 static void repo_set_commondir(struct repository *repo,
 			       const char *commondir)
 {
diff --git a/repository.h b/repository.h
index af6ea0a62c..cf2172c0aa 100644
--- a/repository.h
+++ b/repository.h
@@ -206,6 +206,8 @@ struct repository {
 extern struct repository *the_repository;
 #endif
 
+const char *repo_get_git_dir(struct repository *repo);
+
 /*
  * Define a custom repository layout. Any field can be NULL, which
  * will default back to the path according to the default layout.
diff --git a/setup.c b/setup.c
index 29f8673921..4a9c60922e 100644
--- a/setup.c
+++ b/setup.c
@@ -149,7 +149,7 @@ char *prefix_path(const char *prefix, int len, const char *path)
 	if (!r) {
 		const char *hint_path = get_git_work_tree();
 		if (!hint_path)
-			hint_path = get_git_dir();
+			hint_path = repo_get_git_dir(the_repository);
 		die(_("'%s' is outside repository at '%s'"), path,
 		    absolute_path(hint_path));
 	}
@@ -468,7 +468,7 @@ int is_nonbare_repository_dir(struct strbuf *path)
 int is_inside_git_dir(void)
 {
 	if (inside_git_dir < 0)
-		inside_git_dir = is_inside_dir(get_git_dir());
+		inside_git_dir = is_inside_dir(repo_get_git_dir(the_repository));
 	return inside_git_dir;
 }
 
@@ -1836,7 +1836,7 @@ void check_repository_format(struct repository_format *fmt)
 	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 	if (!fmt)
 		fmt = &repo_fmt;
-	check_repository_format_gently(get_git_dir(), fmt, NULL);
+	check_repository_format_gently(repo_get_git_dir(the_repository), fmt, NULL);
 	startup_info->have_repository = 1;
 	repo_set_hash_algo(the_repository, fmt->hash_algo);
 	repo_set_compat_hash_algo(the_repository, fmt->compat_hash_algo);
@@ -2224,7 +2224,7 @@ static int create_default_files(const char *template_path,
 	 * shared-repository settings, we would need to fix them up.
 	 */
 	if (get_shared_repository()) {
-		adjust_shared_perm(get_git_dir());
+		adjust_shared_perm(repo_get_git_dir(the_repository));
 	}
 
 	initialize_repository_version(fmt->hash_algo, fmt->ref_storage_format, 0);
@@ -2434,12 +2434,12 @@ int init_db(const char *git_dir, const char *real_git_dir,
 			die(_("%s already exists"), real_git_dir);
 
 		set_git_dir(real_git_dir, 1);
-		git_dir = get_git_dir();
+		git_dir = repo_get_git_dir(the_repository);
 		separate_git_dir(git_dir, original_git_dir);
 	}
 	else {
 		set_git_dir(git_dir, 1);
-		git_dir = get_git_dir();
+		git_dir = repo_get_git_dir(the_repository);
 	}
 	startup_info->have_repository = 1;
 
diff --git a/setup.h b/setup.h
index cd8dbc2497..fd2df7cd52 100644
--- a/setup.h
+++ b/setup.h
@@ -176,7 +176,7 @@ int verify_repository_format(const struct repository_format *format,
 			     struct strbuf *err);
 
 /*
- * Check the repository format version in the path found in get_git_dir(),
+ * Check the repository format version in the path found in repo_get_git_dir(the_repository),
  * and die if it is a version we don't understand. Generally one would
  * set_git_dir() before calling this, and use it only for "are we in a valid
  * repo?".
diff --git a/trace.c b/trace.c
index 8669ddfca2..32c5cda7af 100644
--- a/trace.c
+++ b/trace.c
@@ -21,9 +21,12 @@
  *  along with this program; if not, see <https://www.gnu.org/licenses/>.
  */
 
+#define USE_THE_REPOSITORY_VARIABLE
+
 #include "git-compat-util.h"
 #include "abspath.h"
 #include "environment.h"
+#include "repository.h"
 #include "quote.h"
 #include "setup.h"
 #include "trace.h"
@@ -311,7 +314,7 @@ void trace_repo_setup(void)
 	if (!startup_info->prefix)
 		prefix = "(null)";
 
-	trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(get_git_dir()));
+	trace_printf_key(&trace_setup_key, "setup: git_dir: %s\n", quote_crnl(repo_get_git_dir(the_repository)));
 	trace_printf_key(&trace_setup_key, "setup: git_common_dir: %s\n", quote_crnl(get_git_common_dir()));
 	trace_printf_key(&trace_setup_key, "setup: worktree: %s\n", quote_crnl(git_work_tree));
 	trace_printf_key(&trace_setup_key, "setup: cwd: %s\n", quote_crnl(cwd));
diff --git a/transport-helper.c b/transport-helper.c
index 09b3560ffd..abe16eea65 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -143,7 +143,7 @@ static struct child_process *get_helper(struct transport *transport)
 
 	if (have_git_dir())
 		strvec_pushf(&helper->env, "%s=%s",
-			     GIT_DIR_ENVIRONMENT, get_git_dir());
+			     GIT_DIR_ENVIRONMENT, repo_get_git_dir(the_repository));
 
 	helper->trace2_child_class = helper->args.v[0]; /* "remote-<name>" */
 
diff --git a/worktree.c b/worktree.c
index 30a947426e..11335c5d9a 100644
--- a/worktree.c
+++ b/worktree.c
@@ -57,7 +57,7 @@ static void add_head_info(struct worktree *wt)
 
 static int is_current_worktree(struct worktree *wt)
 {
-	char *git_dir = absolute_pathdup(get_git_dir());
+	char *git_dir = absolute_pathdup(repo_get_git_dir(the_repository));
 	const char *wt_git_dir = get_worktree_git_dir(wt);
 	int is_current = !fspathcmp(git_dir, absolute_path(wt_git_dir));
 	free(git_dir);
@@ -171,7 +171,7 @@ struct worktree **get_worktrees(void)
 const char *get_worktree_git_dir(const struct worktree *wt)
 {
 	if (!wt)
-		return get_git_dir();
+		return repo_get_git_dir(the_repository);
 	else if (!wt->id)
 		return get_git_common_dir();
 	else