config: read both home and xdg files for --global

builtin/config.c

@@ -768,6 +768,18 @@ static void location_options_init(struct config_location_options *opts,
 	}
 
 	if (opts->use_global_config) {
+		/*
+		 * Reading config is handled by `config.c#do_git_config_sequence()`
+		 * because the global config can be sourced from multiple files.
+		 * Writing config should point to a single destination as set in
+		 * `opts->source.file` below.
+		 */
+		opts->options.ignore_repo = 1;
+		opts->options.ignore_cmdline= 1;
+		opts->options.ignore_worktree = 1;
+		opts->options.ignore_system = 1;
+		opts->source.scope = CONFIG_SCOPE_GLOBAL;
+
 		opts->source.file = opts->file_to_free = git_global_config();
 		if (!opts->source.file)
 			/*

config.c

@@ -2014,11 +2014,13 @@ int git_config_system(void)
 }
 
 static int do_git_config_sequence(const struct config_options *opts,
-				  const struct repository *repo,
-				  config_fn_t fn, void *data)
+				  const struct repository *repo, config_fn_t fn,
+				  void *data, enum config_scope scope)
 {
 	int ret = 0;
 	char *system_config = git_system_config();
+	int global_config_success_count = 0;
+	int nonzero_ret_on_global_config_error = scope == CONFIG_SCOPE_GLOBAL;
 	char *xdg_config = NULL;
 	char *user_config = NULL;
 	char *repo_config;
@@ -2040,22 +2042,43 @@ static int do_git_config_sequence(const struct config_options *opts,
 		worktree_config = NULL;
 	}
 
-	if (git_config_system() && system_config &&
+	if (!opts->ignore_system && git_config_system() && system_config &&
 	    !access_or_die(system_config, R_OK,
 			   opts->system_gently ? ACCESS_EACCES_OK : 0))
 		ret += git_config_from_file_with_options(fn, system_config,
 							 data, CONFIG_SCOPE_SYSTEM,
 							 NULL);
 
-	git_global_config_paths(&user_config, &xdg_config);
+	if (!opts->ignore_global) {
+		git_global_config_paths(&user_config, &xdg_config);
+
+		if (xdg_config &&
+		    !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK)) {
+			ret += git_config_from_file_with_options(fn, xdg_config,
+								 data,
+								 CONFIG_SCOPE_GLOBAL,
+								 NULL);
+			if (nonzero_ret_on_global_config_error && !ret)
+				++global_config_success_count;
+		}
+
+		if (user_config &&
+		    !access_or_die(user_config, R_OK, ACCESS_EACCES_OK)) {
+			ret += git_config_from_file_with_options(fn, user_config,
+								 data,
+								 CONFIG_SCOPE_GLOBAL,
+								 NULL);
+			if (nonzero_ret_on_global_config_error && !ret)
+				++global_config_success_count;
+		}
 
-	if (xdg_config && !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK))
-		ret += git_config_from_file_with_options(fn, xdg_config, data,
-							 CONFIG_SCOPE_GLOBAL, NULL);
+		if (nonzero_ret_on_global_config_error &&
+		    !global_config_success_count)
+			--ret;
 
-	if (user_config && !access_or_die(user_config, R_OK, ACCESS_EACCES_OK))
-		ret += git_config_from_file_with_options(fn, user_config, data,
-							 CONFIG_SCOPE_GLOBAL, NULL);
+		free(xdg_config);
+		free(user_config);
+	}
 
 	if (!opts->ignore_repo && repo_config &&
 	    !access_or_die(repo_config, R_OK, 0))
@@ -2074,8 +2097,6 @@ static int do_git_config_sequence(const struct config_options *opts,
 		die(_("unable to parse command-line config"));
 
 	free(system_config);
-	free(xdg_config);
-	free(user_config);
 	free(repo_config);
 	free(worktree_config);
 	return ret;
@@ -2105,15 +2126,19 @@ int config_with_options(config_fn_t fn, void *data,
 	 */
 	if (config_source && config_source->use_stdin) {
 		ret = git_config_from_stdin(fn, data, config_source->scope);
-	} else if (config_source && config_source->file) {
+	} else if (config_source && config_source->file &&
+		   config_source->scope != CONFIG_SCOPE_GLOBAL) {
 		ret = git_config_from_file_with_options(fn, config_source->file,
 							data, config_source->scope,
 							NULL);
 	} else if (config_source && config_source->blob) {
 		ret = git_config_from_blob_ref(fn, repo, config_source->blob,
 					       data, config_source->scope);
 	} else {
-		ret = do_git_config_sequence(opts, repo, fn, data);
+		ret = do_git_config_sequence(opts, repo, fn, data,
+					     config_source ?
+						     config_source->scope :
+						     CONFIG_SCOPE_UNKNOWN);
 	}
 
 	if (inc.remote_urls) {

config.h

@@ -87,6 +87,8 @@ typedef int (*config_parser_event_fn_t)(enum config_event_t type,
 
 struct config_options {
 	unsigned int respect_includes : 1;
+	unsigned int ignore_system : 1;
+	unsigned int ignore_global : 1;
 	unsigned int ignore_repo : 1;
 	unsigned int ignore_worktree : 1;
 	unsigned int ignore_cmdline : 1;

t/t1300-config.sh

@@ -2367,6 +2367,71 @@ test_expect_success '--show-scope with --default' '
 	test_cmp expect actual
 '
 
+test_expect_success 'list with nonexistent global config' '
+	rm -rf "$HOME"/.gitconfig "$HOME"/.config/git/config &&
+	git config ${mode_prefix}list --show-scope
+'
+
+test_expect_success 'list --global with nonexistent global config' '
+	rm -rf "$HOME"/.gitconfig "$HOME"/.config/git/config &&
+	test_must_fail git config ${mode_prefix}list --global --show-scope
+'
+
+test_expect_success 'list --global with only home' '
+	rm -rf "$HOME"/.config/git/config &&
+
+	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
+	cat >"$HOME"/.gitconfig <<-EOF &&
+	[home]
+		config = true
+	EOF
+
+	cat >expect <<-EOF &&
+	global	home.config=true
+	EOF
+	git config ${mode_prefix}list --global --show-scope >output &&
+	test_cmp expect output
+'
+
+test_expect_success 'list --global with only xdg' '
+	rm -f "$HOME"/.gitconfig &&
+
+	test_when_finished rm -rf \"\$HOME\"/.config/git &&
+	mkdir -p "$HOME"/.config/git &&
+	cat >"$HOME"/.config/git/config <<-EOF &&
+	[xdg]
+		config = true
+	EOF
+
+	cat >expect <<-EOF &&
+	global	xdg.config=true
+	EOF
+	git config ${mode_prefix}list --global --show-scope >output &&
+	test_cmp expect output
+'
+
+test_expect_success 'list --global with both home and xdg' '
+	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
+	cat >"$HOME"/.gitconfig <<-EOF &&
+	[home]
+		config = true
+	EOF
+
+	test_when_finished rm -rf \"\$HOME\"/.config/git &&
+	mkdir -p "$HOME"/.config/git &&
+	cat >"$HOME"/.config/git/config <<-EOF &&
+	[xdg]
+		config = true
+	EOF
+
+	cat >expect <<-EOF &&
+	global	xdg.config=true
+	global	home.config=true
+	EOF
+	git config ${mode_prefix}list --global --show-scope >output &&
+	test_cmp expect output
+'
+
 test_expect_success 'override global and system config' '
 	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
 	cat >"$HOME"/.gitconfig <<-EOF &&

t/t1306-xdg-files.sh

@@ -68,7 +68,8 @@ test_expect_success 'read with --list: xdg file exists and ~/.gitconfig exists'
 	>.gitconfig &&
 	echo "[user]" >.gitconfig &&
 	echo "	name = read_gitconfig" >>.gitconfig &&
-	echo user.name=read_gitconfig >expected &&
+	echo user.name=read_config >expected &&
+	echo user.name=read_gitconfig >>expected &&
 	git config --global --list >actual &&
 	test_cmp expected actual
 '