Add git_config_early()

This version of git_config() will be used during repository setup.
As a repository is being set up, $GIT_DIR is not nailed down yet,
git_pathdup() should not be used to get $GIT_DIR/config.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -986,6 +986,7 @@ extern int git_config_parse_parameter(const char *text);
 extern int git_config_parse_environment(void);
 extern int git_config_from_parameters(config_fn_t fn, void *data);
 extern int git_config(config_fn_t fn, void *);
+extern int git_config_early(config_fn_t fn, void *, const char *repo_config);
 extern int git_parse_ulong(const char *, unsigned long *);
 extern int git_config_int(const char *, const char *);
 extern unsigned long git_config_ulong(const char *, const char *);

config.c

@@ -835,10 +835,9 @@ int git_config_from_parameters(config_fn_t fn, void *data)
 	return 0;
 }
 
-int git_config(config_fn_t fn, void *data)
+int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 {
 	int ret = 0, found = 0;
-	char *repo_config = NULL;
 	const char *home = NULL;
 
 	/* Setting $GIT_CONFIG makes git read _only_ the given config file. */
@@ -860,12 +859,10 @@ int git_config(config_fn_t fn, void *data)
 		free(user_config);
 	}
 
-	repo_config = git_pathdup("config");
-	if (!access(repo_config, R_OK)) {
+	if (repo_config && !access(repo_config, R_OK)) {
 		ret += git_config_from_file(fn, repo_config, data);
 		found += 1;
 	}
-	free(repo_config);
 
 	ret += git_config_from_parameters(fn, data);
 	if (config_parameters)
@@ -876,6 +873,18 @@ int git_config(config_fn_t fn, void *data)
 	return ret;
 }
 
+int git_config(config_fn_t fn, void *data)
+{
+	char *repo_config = NULL;
+	int ret;
+
+	repo_config = git_pathdup("config");
+	ret = git_config_early(fn, data, repo_config);
+	if (repo_config)
+		free(repo_config);
+	return ret;
+}
+
 /*
  * Find all the stuff for git_config_set() below.
  */