[PATCH v2 04/13] setup: split up concerns of `setup_git_env_internal()`

[Patrick Steinhardt <ps@pks.im>]

The function `setup_git_env_internal()` does two completely unrelated
things:

  - It configures the repository's gitdir and propagates environment
    variables into it.

  - It configures a couple of global parameters via environment
    variables.

The function is called when we initialize the repository's path, but
it's also called via `chdir_notify_register()` whenever we change the
current working directory. While we indeed have to reconfigure the
gitdir in case it's a relative path, it doesn't make sense to reapply
the global environment variables.

Split up concerns of this function along the above delineation. Handling
of the global environment variables is moved into `init_git()`, as they
can be considered part of our setup procedure.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 common-init.c | 20 ++++++++++++++++
 setup.c       | 73 +++++++++++++++++++++++------------------------------------
 2 files changed, 48 insertions(+), 45 deletions(-)

diff --git a/common-init.c b/common-init.c
index 5cc73f058c..d26c9c1f20 100644
--- a/common-init.c
+++ b/common-init.c
@@ -5,7 +5,10 @@
 #include "exec-cmd.h"
 #include "gettext.h"
 #include "attr.h"
+#include "odb.h"
+#include "parse.h"
 #include "repository.h"
+#include "replace-object.h"
 #include "setup.h"
 #include "strbuf.h"
 #include "trace2.h"
@@ -31,6 +34,22 @@ static void restore_sigpipe_to_default(void)
 	signal(SIGPIPE, SIG_DFL);
 }
 
+static void setup_environment(void)
+{
+	char *git_replace_ref_base;
+	const char *replace_ref_base;
+
+	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
+		disable_replace_refs();
+	replace_ref_base = getenv(GIT_REPLACE_REF_BASE_ENVIRONMENT);
+	git_replace_ref_base = xstrdup(replace_ref_base ? replace_ref_base
+							  : "refs/replace/");
+	update_ref_namespace(NAMESPACE_REPLACE, git_replace_ref_base);
+
+	if (git_env_bool(NO_LAZY_FETCH_ENVIRONMENT, 0))
+		fetch_if_missing = 0;
+}
+
 void init_git(const char **argv)
 {
 	struct strbuf tmp = STRBUF_INIT;
@@ -51,6 +70,7 @@ void init_git(const char **argv)
 	git_setup_gettext();
 
 	initialize_repository(the_repository);
+	setup_environment();
 
 	attr_start();
 
diff --git a/setup.c b/setup.c
index 85fad0d77d..324a235dd1 100644
--- a/setup.c
+++ b/setup.c
@@ -10,7 +10,6 @@
 #include "object-file.h"
 #include "object-name.h"
 #include "refs.h"
-#include "replace-object.h"
 #include "repository.h"
 #include "config.h"
 #include "dir.h"
@@ -1042,38 +1041,19 @@ const char *read_gitfile_gently(const char *path, int *return_error_code)
 	return error_code ? NULL : path;
 }
 
-static void setup_git_env_internal(struct repository *repo,
-				   const char *git_dir)
+static void apply_gitdir_and_environment(struct repository *repo, const char *path)
 {
-	char *git_replace_ref_base;
-	const char *replace_ref_base;
-	struct set_gitdir_args args = { NULL };
 	struct strvec to_free = STRVEC_INIT;
+	struct set_gitdir_args args = {
+		.commondir = getenv_safe(&to_free, GIT_COMMON_DIR_ENVIRONMENT),
+		.graft_file = getenv_safe(&to_free, GRAFT_ENVIRONMENT),
+		.index_file = getenv_safe(&to_free, INDEX_ENVIRONMENT),
+		.disable_ref_updates = !!getenv(GIT_QUARANTINE_ENVIRONMENT),
+	};
 
-	args.commondir = getenv_safe(&to_free, GIT_COMMON_DIR_ENVIRONMENT);
-	args.graft_file = getenv_safe(&to_free, GRAFT_ENVIRONMENT);
-	args.index_file = getenv_safe(&to_free, INDEX_ENVIRONMENT);
-	if (getenv(GIT_QUARANTINE_ENVIRONMENT))
-		args.disable_ref_updates = true;
+	repo_set_gitdir(repo, path, &args);
 
-	repo_set_gitdir(repo, git_dir, &args);
 	strvec_clear(&to_free);
-
-	if (getenv(NO_REPLACE_OBJECTS_ENVIRONMENT))
-		disable_replace_refs();
-	replace_ref_base = getenv(GIT_REPLACE_REF_BASE_ENVIRONMENT);
-	git_replace_ref_base = xstrdup(replace_ref_base ? replace_ref_base
-							  : "refs/replace/");
-	update_ref_namespace(NAMESPACE_REPLACE, git_replace_ref_base);
-
-	if (git_env_bool(NO_LAZY_FETCH_ENVIRONMENT, 0))
-		fetch_if_missing = 0;
-}
-
-static void set_git_dir_1(struct repository *repo, const char *path)
-{
-	xsetenv(GIT_DIR_ENVIRONMENT, path, 1);
-	setup_git_env_internal(repo, path);
 }
 
 static void update_relative_gitdir(const char *name UNUSED,
@@ -1087,11 +1067,12 @@ static void update_relative_gitdir(const char *name UNUSED,
 	trace_printf_key(&trace_setup_key,
 			 "setup: move $GIT_DIR to '%s'",
 			 path);
-	set_git_dir_1(repo, path);
+	apply_gitdir_and_environment(repo, path);
+	xsetenv(GIT_DIR_ENVIRONMENT, path, 1);
 	free(path);
 }
 
-static void set_git_dir(struct repository *repo, const char *path, int make_realpath)
+static void apply_and_export_relative_gitdir(struct repository *repo, const char *path, int make_realpath)
 {
 	struct strbuf realpath = STRBUF_INIT;
 
@@ -1100,7 +1081,9 @@ static void set_git_dir(struct repository *repo, const char *path, int make_real
 		path = realpath.buf;
 	}
 
-	set_git_dir_1(repo, path);
+	apply_gitdir_and_environment(repo, path);
+	xsetenv(GIT_DIR_ENVIRONMENT, path, 1);
+
 	if (!is_absolute_path(path))
 		chdir_notify_register(NULL, update_relative_gitdir, repo);
 
@@ -1153,7 +1136,7 @@ static const char *setup_explicit_git_dir(struct repository *repo,
 		set_git_work_tree(repo, work_tree_env);
 	} else if (repo_fmt->is_bare > 0) {
 		/* #18, #26 */
-		set_git_dir(repo, gitdirenv, 0);
+		apply_and_export_relative_gitdir(repo, gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	} else if (repo_fmt->work_tree) { /* #6, #14 */
@@ -1173,7 +1156,7 @@ static const char *setup_explicit_git_dir(struct repository *repo,
 		}
 	} else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 		/* #16d */
-		set_git_dir(repo, gitdirenv, 0);
+		apply_and_export_relative_gitdir(repo, gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	} else { /* #2, #10 */
@@ -1185,14 +1168,14 @@ static const char *setup_explicit_git_dir(struct repository *repo,
 
 	/* both repo_get_work_tree() and cwd are already normalized */
 	if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
-		set_git_dir(repo, gitdirenv, 0);
+		apply_and_export_relative_gitdir(repo, gitdirenv, 0);
 		free(gitfile);
 		return NULL;
 	}
 
 	offset = dir_inside_of(cwd->buf, worktree);
 	if (offset >= 0) {	/* cwd inside worktree? */
-		set_git_dir(repo, gitdirenv, 1);
+		apply_and_export_relative_gitdir(repo, gitdirenv, 1);
 		if (chdir(worktree))
 			die_errno(_("cannot chdir to '%s'"), worktree);
 		strbuf_addch(cwd, '/');
@@ -1201,7 +1184,7 @@ static const char *setup_explicit_git_dir(struct repository *repo,
 	}
 
 	/* cwd outside worktree */
-	set_git_dir(repo, gitdirenv, 0);
+	apply_and_export_relative_gitdir(repo, gitdirenv, 0);
 	free(gitfile);
 	return NULL;
 }
@@ -1231,7 +1214,7 @@ static const char *setup_discovered_git_dir(struct repository *repo,
 
 	/* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 	if (repo_fmt->is_bare > 0) {
-		set_git_dir(repo, gitdir, (offset != cwd->len));
+		apply_and_export_relative_gitdir(repo, gitdir, (offset != cwd->len));
 		if (chdir(cwd->buf))
 			die_errno(_("cannot come back to cwd"));
 		return NULL;
@@ -1240,7 +1223,7 @@ static const char *setup_discovered_git_dir(struct repository *repo,
 	/* #0, #1, #5, #8, #9, #12, #13 */
 	set_git_work_tree(repo, ".");
 	if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
-		set_git_dir(repo, gitdir, 0);
+		apply_and_export_relative_gitdir(repo, gitdir, 0);
 	if (offset >= cwd->len)
 		return NULL;
 
@@ -1280,10 +1263,10 @@ static const char *setup_bare_git_dir(struct repository *repo,
 			die_errno(_("cannot come back to cwd"));
 		root_len = offset_1st_component(cwd->buf);
 		strbuf_setlen(cwd, offset > root_len ? offset : root_len);
-		set_git_dir(repo, cwd->buf, 0);
+		apply_and_export_relative_gitdir(repo, cwd->buf, 0);
 	}
 	else
-		set_git_dir(repo, ".", 0);
+		apply_and_export_relative_gitdir(repo, ".", 0);
 	return NULL;
 }
 
@@ -1878,7 +1861,7 @@ const char *enter_repo(struct repository *repo, const char *path, unsigned flags
 		struct repository_format fmt = REPOSITORY_FORMAT_INIT;
 		struct strbuf err = STRBUF_INIT;
 
-		set_git_dir(repo, ".", 0);
+		apply_and_export_relative_gitdir(repo, ".", 0);
 		read_and_verify_repository_format(&fmt, ".", NULL);
 		if (apply_repository_format(repo, &fmt, APPLY_REPOSITORY_FORMAT_HONOR_ENV, &err) < 0)
 			die("%s", err.buf);
@@ -2022,7 +2005,7 @@ const char *setup_git_directory_gently(struct repository *repo, int *nongit_ok)
 		startup_info->have_repository = 1;
 
 	/*
-	 * Not all paths through the setup code will call 'set_git_dir()' (which
+	 * Not all paths through the setup code will call 'apply_and_export_relative_gitdir()' (which
 	 * directly sets up the environment) so in order to guarantee that the
 	 * environment is in a consistent state after setup, explicitly setup
 	 * the environment if we have a repository.
@@ -2040,7 +2023,7 @@ const char *setup_git_directory_gently(struct repository *repo, int *nongit_ok)
 			const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
 			if (!gitdir)
 				gitdir = DEFAULT_GIT_DIR_ENVIRONMENT;
-			setup_git_env_internal(repo, gitdir);
+			apply_gitdir_and_environment(repo, gitdir);
 		}
 
 		if (startup_info->have_repository) {
@@ -2825,12 +2808,12 @@ int init_db(struct repository *repo,
 		if (!exist_ok && !stat(real_git_dir, &st))
 			die(_("%s already exists"), real_git_dir);
 
-		set_git_dir(repo, real_git_dir, 1);
+		apply_and_export_relative_gitdir(repo, real_git_dir, 1);
 		git_dir = repo_get_git_dir(repo);
 		separate_git_dir(git_dir, original_git_dir);
 	}
 	else {
-		set_git_dir(repo, git_dir, 1);
+		apply_and_export_relative_gitdir(repo, git_dir, 1);
 		git_dir = repo_get_git_dir(repo);
 	}
 	startup_info->have_repository = 1;

-- 
2.55.0.141.g00534a21ce.dirty