maintenance: use XDG config if it exists

`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 50a044f (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 <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: LemmingAvalanche

builtin/gc.c

@@ -1543,19 +1543,18 @@ static int maintenance_register(int argc, const char **argv, const char *prefix)
 
 	if (!found) {
 		int rc;
-		char *user_config = NULL, *xdg_config = NULL;
+		char *global_config_file = NULL;
 
 		if (!config_file) {
-			git_global_config_paths(&user_config, &xdg_config);
-			config_file = user_config;
-			if (!user_config)
-				die(_("$HOME not set"));
+			global_config_file = git_global_config();
+			config_file = global_config_file;
 		}
+		if (!config_file)
+			die(_("$HOME not set"));
 		rc = git_config_set_multivar_in_file_gently(
 			config_file, "maintenance.repo", maintpath,
 			CONFIG_REGEX_NONE, 0);
-		free(user_config);
-		free(xdg_config);
+		free(global_config_file);
 
 		if (rc)
 			die(_("unable to add '%s' value of '%s'"),
@@ -1612,18 +1611,18 @@ static int maintenance_unregister(int argc, const char **argv, const char *prefi
 
 	if (found) {
 		int rc;
-		char *user_config = NULL, *xdg_config = NULL;
+		char *global_config_file = NULL;
+
 		if (!config_file) {
-			git_global_config_paths(&user_config, &xdg_config);
-			config_file = user_config;
-			if (!user_config)
-				die(_("$HOME not set"));
+			global_config_file = git_global_config();
+			config_file = global_config_file;
 		}
+		if (!config_file)
+			die(_("$HOME not set"));
 		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);
+		free(global_config_file);
 
 		if (rc &&
 		    (!force || rc == CONFIG_NOTHING_SET))

t/t7900-maintenance.sh

@@ -67,6 +67,51 @@ 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' '
+	test_when_finished rm -r .config/git/config &&
+	(
+		XDG_CONFIG_HOME=.config &&
+		export XDG_CONFIG_HOME &&
+		mkdir -p $XDG_CONFIG_HOME/git &&
+		>$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 'unregister uses XDG_CONFIG_HOME config if it exists' '
+	test_when_finished rm -r .config/git/config &&
+	(
+		XDG_CONFIG_HOME=.config &&
+		export XDG_CONFIG_HOME &&
+		mkdir -p $XDG_CONFIG_HOME/git &&
+		>$XDG_CONFIG_HOME/git/config &&
+		git maintenance register &&
+		git maintenance unregister &&
+		test_must_fail git config --file=$XDG_CONFIG_HOME/git/config --get maintenance.repo >actual &&
+		test_must_be_empty actual
+	)
+'
+
+test_expect_success 'unregister does not need XDG_CONFIG_HOME config to exist' '
+	test_path_is_missing $XDG_CONFIG_HOME/git/config &&
+	git maintenance register &&
+	git maintenance unregister &&
+	test_must_fail git config --global --get maintenance.repo >actual &&
+	test_must_be_empty actual
+'
+
 test_expect_success 'maintenance.<task>.enabled' '
 	git config maintenance.gc.enabled false &&
 	git config maintenance.commit-graph.enabled true &&