environment: make `get_index_file()` accept a repository

The `get_index_file()` function retrieves the path to the index file
of `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>

builtin/am.c

@@ -1668,7 +1668,9 @@ static void do_commit(const struct am_state *state)
 	if (!state->no_verify && run_hooks(the_repository, "pre-applypatch"))
 		exit(1);
 
-	if (write_index_as_tree(&tree, the_repository->index, get_index_file(), 0, NULL))
+	if (write_index_as_tree(&tree, the_repository->index,
+				repo_get_index_file(the_repository),
+				0, NULL))
 		die(_("git write-tree failed to write a tree"));
 
 	if (!repo_get_oid_commit(the_repository, "HEAD", &parent)) {
@@ -2078,7 +2080,9 @@ static int clean_index(const struct object_id *head, const struct object_id *rem
 	if (fast_forward_to(head_tree, head_tree, 1))
 		return -1;
 
-	if (write_index_as_tree(&index, the_repository->index, get_index_file(), 0, NULL))
+	if (write_index_as_tree(&index, the_repository->index,
+				repo_get_index_file(the_repository),
+				0, NULL))
 		return -1;
 
 	index_tree = parse_tree_indirect(&index);

builtin/commit.c

@@ -473,7 +473,7 @@ static const char *prepare_index(const char **argv, const char *prefix,
 				       COMMIT_LOCK | SKIP_IF_UNCHANGED))
 			die(_("unable to write new index file"));
 		commit_style = COMMIT_AS_IS;
-		ret = get_index_file();
+		ret = repo_get_index_file(the_repository);
 		goto out;
 	}
 
@@ -1874,8 +1874,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 
 	repo_rerere(the_repository, 0);
 	run_auto_maintenance(quiet);
-	run_commit_hook(use_editor, get_index_file(), NULL, "post-commit",
-			NULL);
+	run_commit_hook(use_editor, repo_get_index_file(the_repository),
+			NULL, "post-commit", NULL);
 	if (amend && !no_post_rewrite) {
 		commit_post_rewrite(the_repository, current_head, &oid);
 	}

builtin/merge.c

@@ -696,7 +696,9 @@ static int read_tree_trivial(struct object_id *common, struct object_id *head,
 
 static void write_tree_trivial(struct object_id *oid)
 {
-	if (write_index_as_tree(oid, the_repository->index, get_index_file(), 0, NULL))
+	if (write_index_as_tree(oid, the_repository->index,
+				repo_get_index_file(the_repository),
+				0, NULL))
 		die(_("git write-tree failed to write a tree"));
 }
 
@@ -758,7 +760,7 @@ static int try_merge_strategy(const char *strategy, struct commit_list *common,
 		}
 		if (write_locked_index(the_repository->index, &lock,
 				       COMMIT_LOCK | SKIP_IF_UNCHANGED))
-			die(_("unable to write %s"), get_index_file());
+			die(_("unable to write %s"), repo_get_index_file(the_repository));
 		return clean ? 0 : 1;
 	} else {
 		return try_merge_command(the_repository,
@@ -840,7 +842,7 @@ static void write_merge_heads(struct commit_list *);
 static void prepare_to_commit(struct commit_list *remoteheads)
 {
 	struct strbuf msg = STRBUF_INIT;
-	const char *index_file = get_index_file();
+	const char *index_file = repo_get_index_file(the_repository);
 
 	if (!no_verify) {
 		int invoked_hook;
@@ -880,8 +882,8 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 		append_signoff(&msg, ignored_log_message_bytes(msg.buf, msg.len), 0);
 	write_merge_heads(remoteheads);
 	write_file_buf(git_path_merge_msg(the_repository), msg.buf, msg.len);
-	if (run_commit_hook(0 < option_edit, get_index_file(), NULL,
-			    "prepare-commit-msg",
+	if (run_commit_hook(0 < option_edit, repo_get_index_file(the_repository),
+			    NULL, "prepare-commit-msg",
 			    git_path_merge_msg(the_repository), "merge", NULL))
 		abort_commit(remoteheads, NULL);
 	if (0 < option_edit) {
@@ -889,7 +891,7 @@ static void prepare_to_commit(struct commit_list *remoteheads)
 			abort_commit(remoteheads, NULL);
 	}
 
-	if (!no_verify && run_commit_hook(0 < option_edit, get_index_file(),
+	if (!no_verify && run_commit_hook(0 < option_edit, repo_get_index_file(the_repository),
 					  NULL, "commit-msg",
 					  git_path_merge_msg(the_repository), NULL))
 		abort_commit(remoteheads, NULL);

builtin/stash.c

@@ -540,8 +540,8 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 					 NULL, NULL, NULL))
 		return error(_("could not write index"));
 
-	if (write_index_as_tree(&c_tree, the_repository->index, get_index_file(), 0,
-				NULL))
+	if (write_index_as_tree(&c_tree, the_repository->index,
+				repo_get_index_file(the_repository), 0, NULL))
 		return error(_("cannot apply a stash in the middle of a merge"));
 
 	if (index) {
@@ -566,7 +566,7 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 			discard_index(the_repository->index);
 			repo_read_index(the_repository);
 			if (write_index_as_tree(&index_tree, the_repository->index,
-						get_index_file(), 0, NULL))
+						repo_get_index_file(the_repository), 0, NULL))
 				return error(_("could not save index tree"));
 
 			reset_head();
@@ -1406,8 +1406,8 @@ static int do_create_stash(const struct pathspec *ps, struct strbuf *stash_msg_b
 
 	strbuf_addf(&commit_tree_label, "index on %s\n", msg.buf);
 	commit_list_insert(head_commit, &parents);
-	if (write_index_as_tree(&info->i_tree, the_repository->index, get_index_file(), 0,
-				NULL) ||
+	if (write_index_as_tree(&info->i_tree, the_repository->index,
+				repo_get_index_file(the_repository), 0, NULL) ||
 	    commit_tree(commit_tree_label.buf, commit_tree_label.len,
 			&info->i_tree, parents, &info->i_commit, NULL, NULL)) {
 		if (!quiet)
@@ -1905,7 +1905,7 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
 
-	index_file = get_index_file();
+	index_file = repo_get_index_file(the_repository);
 	strbuf_addf(&stash_index_path, "%s.stash.%" PRIuMAX, index_file,
 		    (uintmax_t)pid);
 

builtin/update-index.c

@@ -1239,7 +1239,7 @@ int cmd_update_index(int argc, const char **argv, const char *prefix)
 		if (newfd < 0) {
 			if (refresh_args.flags & REFRESH_QUIET)
 				exit(128);
-			unable_to_lock_die(get_index_file(), lock_error);
+			unable_to_lock_die(repo_get_index_file(the_repository), lock_error);
 		}
 		if (write_locked_index(the_repository->index, &lock_file, COMMIT_LOCK))
 			die("Unable to write new index file");

builtin/write-tree.c

@@ -6,7 +6,6 @@
 
 #include "builtin.h"
 #include "config.h"
-#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "tree.h"
@@ -44,7 +43,8 @@ int cmd_write_tree(int argc, const char **argv, const char *cmd_prefix)
 	prepare_repo_settings(the_repository);
 	the_repository->settings.command_requires_full_index = 0;
 
-	ret = write_index_as_tree(&oid, the_repository->index, get_index_file(),
+	ret = write_index_as_tree(&oid, the_repository->index,
+				  repo_get_index_file(the_repository),
 				  flags, tree_prefix);
 	switch (ret) {
 	case 0:

environment.c

@@ -306,13 +306,6 @@ int odb_pack_keep(const char *name)
 	return open(name, O_RDWR|O_CREAT|O_EXCL, 0600);
 }
 
-char *get_index_file(void)
-{
-	if (!the_repository->index_file)
-		BUG("git environment hasn't been setup");
-	return the_repository->index_file;
-}
-
 char *get_graft_file(struct repository *r)
 {
 	if (!r->graft_file)

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;
-char *get_index_file(void);
 char *get_graft_file(struct repository *r);
 void set_git_dir(const char *path, int make_realpath);
 const char *get_git_namespace(void);

repository.c

@@ -112,6 +112,13 @@ const char *repo_get_object_directory(struct repository *repo)
 	return repo->objects->odb->path;
 }
 
+const char *repo_get_index_file(struct repository *repo)
+{
+	if (!repo->index_file)
+		BUG("repository hasn't been set up");
+	return repo->index_file;
+}
+
 static void repo_set_commondir(struct repository *repo,
 			       const char *commondir)
 {

repository.h

@@ -209,6 +209,7 @@ extern struct repository *the_repository;
 const char *repo_get_git_dir(struct repository *repo);
 const char *repo_get_common_dir(struct repository *repo);
 const char *repo_get_object_directory(struct repository *repo);
+const char *repo_get_index_file(struct repository *repo);
 
 /*
  * Define a custom repository layout. Any field can be NULL, which

wt-status.c

@@ -16,6 +16,7 @@
 #include "revision.h"
 #include "diffcore.h"
 #include "quote.h"
+#include "repository.h"
 #include "run-command.h"
 #include "strvec.h"
 #include "remote.h"
@@ -152,7 +153,7 @@ void wt_status_prepare(struct repository *r, struct wt_status *s)
 					"HEAD", 0, NULL, NULL);
 	s->reference = "HEAD";
 	s->fp = stdout;
-	s->index_file = get_index_file();
+	s->index_file = repo_get_index_file(the_repository);
 	s->change.strdup_strings = 1;
 	s->untracked.strdup_strings = 1;
 	s->ignored.strdup_strings = 1;