[PATCH v1 4/4] maintenance: use XDG config if it exists

[Kristoffer Haugsbakk <code@khaugsbakk.name>]

`git maintenance register` registers the repository in the user's global
config. `$XDG_CONFIG_HOME/git/config` is supposed to be used if
`~/.gitconfig` does not exist. However, this command creates a
`~/.gitconfig` file and writes to that one even though the XDG variant
exists.

This used to work correctly until 50a044f1e4 (gc: replace config
subprocesses with API calls, 2022-09-27), when the command started calling
the config API instead of git-config(1).

Also change `unregister` accordingly.

Signed-off-by: Kristoffer Haugsbakk <code@khaugsbakk.name>
---
 builtin/gc.c           | 23 +++++------------------
 t/t7900-maintenance.sh | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/builtin/gc.c b/builtin/gc.c
index 17fc031f63a..7b780f2ab38 100644
--- a/builtin/gc.c
+++ b/builtin/gc.c
@@ -1526,19 +1526,12 @@ static int maintenance_register(int argc, const char **argv, const char *prefix)
 
 	if (!found) {
 		int rc;
-		char *user_config = NULL, *xdg_config = NULL;
 
-		if (!config_file) {
-			git_global_config_paths(&user_config, &xdg_config);
-			config_file = user_config;
-			if (!user_config)
-				die(_("$HOME not set"));
-		}
+		if (!config_file)
+			config_file = git_global_config();
 		rc = git_config_set_multivar_in_file_gently(
 			config_file, "maintenance.repo", maintpath,
 			CONFIG_REGEX_NONE, 0);
-		free(user_config);
-		free(xdg_config);
 
 		if (rc)
 			die(_("unable to add '%s' value of '%s'"),
@@ -1595,18 +1588,12 @@ static int maintenance_unregister(int argc, const char **argv, const char *prefi
 
 	if (found) {
 		int rc;
-		char *user_config = NULL, *xdg_config = NULL;
-		if (!config_file) {
-			git_global_config_paths(&user_config, &xdg_config);
-			config_file = user_config;
-			if (!user_config)
-				die(_("$HOME not set"));
-		}
+
+		if (!config_file)
+			config_file = git_global_config();
 		rc = git_config_set_multivar_in_file_gently(
 			config_file, key, NULL, maintpath,
 			CONFIG_FLAGS_MULTI_REPLACE | CONFIG_FLAGS_FIXED_VALUE);
-		free(user_config);
-		free(xdg_config);
 
 		if (rc &&
 		    (!force || rc == CONFIG_NOTHING_SET))
diff --git a/t/t7900-maintenance.sh b/t/t7900-maintenance.sh
index 487e326b3fa..a11e6c61520 100755
--- a/t/t7900-maintenance.sh
+++ b/t/t7900-maintenance.sh
@@ -67,6 +67,27 @@ test_expect_success 'maintenance.auto config option' '
 	test_subcommand ! git maintenance run --auto --quiet  <false
 '
 
+test_expect_success 'register uses XDG_CONFIG_HOME config if it exists' '
+	XDG_CONFIG_HOME=.config &&
+	test_when_finished rm -r "$XDG_CONFIG_HOME"/git/config &&
+	export "XDG_CONFIG_HOME" &&
+	mkdir -p "$XDG_CONFIG_HOME"/git &&
+	touch "$XDG_CONFIG_HOME"/git/config &&
+	git maintenance register &&
+	git config --file="$XDG_CONFIG_HOME"/git/config --get maintenance.repo >actual &&
+	pwd >expect &&
+	test_cmp expect actual
+'
+
+test_expect_success 'register does not need XDG_CONFIG_HOME config to exist' '
+	test_when_finished git maintenance unregister &&
+	test_path_is_missing "$XDG_CONFIG_HOME"/git/config &&
+	git maintenance register &&
+	git config --global --get maintenance.repo >actual &&
+	pwd >expect &&
+	test_cmp expect actual
+'
+
 test_expect_success 'maintenance.<task>.enabled' '
 	git config maintenance.gc.enabled false &&
 	git config maintenance.commit-graph.enabled true &&
-- 
2.42.0.2.g879ad04204