Introduce is_bare_repository() and core.bare configuration variable

This removes the old is_bare_git_dir(const char *) to ask if a
directory, if it is a GIT_DIR, is a bare repository, and
replaces it with is_bare_repository(void *).  The function looks
at core.bare configuration variable if exists but uses the old
heuristics: if it is ".git" or ends with "/.git", then it does
not look like a bare repository, otherwise it does.

Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-init-db.c

@@ -252,9 +252,13 @@ static int create_default_files(const char *git_dir, const char *template_path)
 	}
 	git_config_set("core.filemode", filemode ? "true" : "false");
 
-	/* Enable logAllRefUpdates if a working tree is attached */
-	if (!is_bare_git_dir(git_dir))
+	if (is_bare_repository()) {
+		git_config_set("core.bare", "true");
+	}
+	else {
+		git_config_set("core.bare", "false");
 		git_config_set("core.logallrefupdates", "true");
+	}
 	return reinit;
 }
 

cache.h

@@ -127,7 +127,8 @@ extern int cache_errno;
 #define CONFIG_LOCAL_ENVIRONMENT "GIT_CONFIG_LOCAL"
 #define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
 
-extern int is_bare_git_dir(const char *dir);
+extern int is_bare_repository_cfg;
+extern int is_bare_repository(void);
 extern const char *get_git_dir(void);
 extern char *get_object_directory(void);
 extern char *get_refs_directory(void);

config.c

@@ -269,6 +269,11 @@ int git_default_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.bare")) {
+		is_bare_repository_cfg = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp(var, "core.ignorestat")) {
 		assume_unchanged = git_config_bool(var, value);
 		return 0;

environment.c

@@ -15,6 +15,7 @@ int use_legacy_headers = 1;
 int trust_executable_bit = 1;
 int assume_unchanged;
 int prefer_symlink_refs;
+int is_bare_repository_cfg = -1; /* unspecified */
 int log_all_ref_updates = -1; /* unspecified */
 int warn_ambiguous_refs = 1;
 int repository_format_version;
@@ -53,9 +54,13 @@ static void setup_git_env(void)
 		git_graft_file = xstrdup(git_path("info/grafts"));
 }
 
-int is_bare_git_dir(const char *dir)
+int is_bare_repository(void)
 {
-	const char *s;
+	const char *dir, *s;
+	if (0 <= is_bare_repository_cfg)
+		return is_bare_repository_cfg;
+
+	dir = get_git_dir();
 	if (!strcmp(dir, DEFAULT_GIT_DIR_ENVIRONMENT))
 		return 0;
 	s = strrchr(dir, '/');

refs.c

@@ -924,7 +924,7 @@ static int log_ref_write(struct ref_lock *lock,
 	const char *committer;
 
 	if (log_all_ref_updates < 0)
-		log_all_ref_updates = !is_bare_git_dir(get_git_dir());
+		log_all_ref_updates = !is_bare_repository();
 
 	if (log_all_ref_updates &&
 	    (!strncmp(lock->ref_name, "refs/heads/", 11) ||