config: read (but not write) from $XDG_CONFIG_HOME/git/config file

Teach git to read the "gitconfig" information from a new location,
$XDG_CONFIG_HOME/git/config; this allows the user to avoid
cluttering $HOME with many per-application configuration files.

In the order of reading, this file comes between the global
configuration file (typically $HOME/.gitconfig) and the system wide
configuration file (typically /etc/gitconfig).

We do not write to this new location (yet).

If $XDG_CONFIG_HOME is either not set or empty, $HOME/.config/git/config
will be used. This is in line with XDG specification.

If the new file does not exist, the behavior is unchanged.

Signed-off-by: Huynh Khoi Nguyen Nguyen <Huynh-Khoi-Nguyen.Nguyen@ensimag.imag.fr>
Signed-off-by: Valentin Duperray <Valentin.Duperray@ensimag.imag.fr>
Signed-off-by: Franck Jonas <Franck.Jonas@ensimag.imag.fr>
Signed-off-by: Lucien Kong <Lucien.Kong@ensimag.imag.fr>
Signed-off-by: Thomas Nguy <Thomas.Nguy@ensimag.imag.fr>
Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 9 deletions

diff --git a/builtin/config.c b/builtin/config.c
index 33c8820af6..da54fd1e12 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -161,7 +161,7 @@ static int show_config(const char *key_, const char *value_, void *cb)
 static int get_value(const char *key_, const char *regex_)
 {
 	int ret = -1;
-	char *global = NULL, *repo_config = NULL;
+	char *global = NULL, *xdg = NULL, *repo_config = NULL;
 	const char *system_wide = NULL, *local;
 	struct config_include_data inc = CONFIG_INCLUDE_INIT;
 	config_fn_t fn;
@@ -169,12 +169,10 @@ static int get_value(const char *key_, const char *regex_)
 
 	local = given_config_file;
 	if (!local) {
-		const char *home = getenv("HOME");
 		local = repo_config = git_pathdup("config");
-		if (home)
-			global = xstrdup(mkpath("%s/.gitconfig", home));
 		if (git_config_system())
 			system_wide = git_etc_gitconfig();
+		home_config_paths(&global, &xdg, "config");
 	}
 
 	if (use_key_regexp) {
@@ -229,6 +227,8 @@ static int get_value(const char *key_, const char *regex_)
 
 	if (do_all && system_wide)
 		git_config_from_file(fn, system_wide, data);
+	if (do_all && xdg)
+		git_config_from_file(fn, xdg, data);
 	if (do_all && global)
 		git_config_from_file(fn, global, data);
 	if (do_all)
@@ -238,6 +238,8 @@ static int get_value(const char *key_, const char *regex_)
 		git_config_from_file(fn, local, data);
 	if (!do_all && !seen && global)
 		git_config_from_file(fn, global, data);
+	if (!do_all && !seen && xdg)
+		git_config_from_file(fn, xdg, data);
 	if (!do_all && !seen && system_wide)
 		git_config_from_file(fn, system_wide, data);
 
@@ -255,6 +257,7 @@ static int get_value(const char *key_, const char *regex_)
 free_strings:
 	free(repo_config);
 	free(global);
+	free(xdg);
 	return ret;
 }
 
@@ -379,13 +382,20 @@ int cmd_config(int argc, const char **argv, const char *prefix)
 	}
 
 	if (use_global_config) {
-		char *home = getenv("HOME");
-		if (home) {
-			char *user_config = xstrdup(mkpath("%s/.gitconfig", home));
+		char *user_config = NULL;
+		char *xdg_config = NULL;
+
+		home_config_paths(&user_config, &xdg_config, "config");
+
+		if (access(user_config, R_OK) && !access(xdg_config, R_OK) &&
+		    (actions == ACTION_LIST ||
+		     actions == ACTION_GET_COLOR ||
+		     actions == ACTION_GET_COLORBOOL))
+			given_config_file = xdg_config;
+		else if (user_config)
 			given_config_file = user_config;
-		} else {
+		else
 			die("$HOME not set");
-		}
 	}
 	else if (use_system_config)
 		given_config_file = git_etc_gitconfig();