[PATCH v3 2/2] config: read global scope via config_sequence

@@ -957,6 +957,17 @@ static void location_options_init(struct config_location_options *opts,
 	}
 
 	if (opts->use_global_config) {
+		/*
+		 * Since global config is sourced from more than one location,
+		 * read it using `do_git_config_sequence()` with other scopes
+		 * ignored. However, writing global config should point to a
+		 * single destination, set in `opts->source.file`.
+		 */
+		opts->options.ignore_repo = 1;
+		opts->options.ignore_cmdline = 1;
+		opts->options.ignore_worktree = 1;
+		opts->options.ignore_system = 1;
+
 		opts->source.file = opts->file_to_free = git_global_config();
 		if (!opts->source.file)
 			/*

@@ -82,7 +82,9 @@ static char *git_attr_val_global(int ident_flag UNUSED)
 
 static char *git_config_val_system(int ident_flag UNUSED)
 {
-	if (git_config_system()) {
+	const struct config_options opts = { 0 };
+
+	if (git_config_system(&opts)) {
 		char *file = git_system_config();
 		normalize_path_copy(file, file);
 		return file;

@@ -1554,16 +1554,18 @@ void git_global_config_paths(char **user_out, char **xdg_out)
 	*xdg_out = xdg_config;
 }
 
-int git_config_system(void)
+int git_config_system(const struct config_options *opts)
 {
-	return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
+	return !opts->ignore_system && !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 }
 
 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, int require_global_scope_success)
 {
+	int tmp_ret;
 	int ret = 0;
+	int global_had_success = 0;
 	char *system_config = git_system_config();
 	char *xdg_config = NULL;
 	char *user_config = NULL;

@@ -1586,7 +1588,7 @@ static int do_git_config_sequence(const struct config_options *opts,
 		worktree_config = NULL;
 	}
 
-	if (git_config_system() && system_config &&
+	if (git_config_system(opts) && 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,

@@ -1595,13 +1597,25 @@ static int do_git_config_sequence(const struct config_options *opts,
 
 	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 (xdg_config &&
+	    !access_or_die(xdg_config, R_OK, ACCESS_EACCES_OK)) {
+		tmp_ret = git_config_from_file_with_options(fn, xdg_config,
+							    data, CONFIG_SCOPE_GLOBAL,
+							    NULL);
+		ret += tmp_ret;
+		if (!tmp_ret)
+			global_had_success = 1;
+	}
 
-	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 (user_config &&
+	    !access_or_die(user_config, R_OK, ACCESS_EACCES_OK)) {
+		tmp_ret = git_config_from_file_with_options(fn, user_config,
+							    data, CONFIG_SCOPE_GLOBAL,
+							    NULL);
+		ret += tmp_ret;
+		if (!tmp_ret)
+			global_had_success = 1;
+	}
 
 	if (!opts->ignore_repo && repo_config &&
 	    !access_or_die(repo_config, R_OK, 0))

@@ -1624,6 +1638,10 @@ static int do_git_config_sequence(const struct config_options *opts,
 	free(user_config);
 	free(repo_config);
 	free(worktree_config);
+
+	if (require_global_scope_success && !global_had_success && !ret)
+		ret = -1;
+
 	return ret;
 }
 

@@ -1646,11 +1664,15 @@ int config_with_options(config_fn_t fn, void *data,
 	}
 
 	/*
-	 * If we have a specific filename, use it. Otherwise, follow the
-	 * regular lookup sequence.
+	 * Use the specified file when provided, except for the global scope,
+	 * which can come from more than one file. With no explicit source,
+	 * follow the regular lookup sequence.
 	 */
 	if (config_source && config_source->use_stdin) {
 		ret = git_config_from_stdin(fn, data, config_source->scope);
+	} else if (config_source && config_source->file &&
+		   config_source->scope == CONFIG_SCOPE_GLOBAL) {
+		ret = do_git_config_sequence(opts, repo, fn, data, 1);
 	} else if (config_source && config_source->file) {
 		ret = git_config_from_file_with_options(fn, config_source->file,
 							data, config_source->scope,

@@ -1659,7 +1681,7 @@ int config_with_options(config_fn_t fn, void *data,
 		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, 0);
 	}
 
 	if (inc.remote_urls) {

@@ -88,6 +88,7 @@ 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_repo : 1;
 	unsigned int ignore_worktree : 1;
 	unsigned int ignore_cmdline : 1;

@@ -423,7 +424,7 @@ int repo_config_rename_section(struct repository *, const char *, const char *);
 int repo_config_rename_section_in_file(struct repository *, const char *, const char *, const char *);
 int repo_config_copy_section(struct repository *, const char *, const char *);
 int repo_config_copy_section_in_file(struct repository *, const char *, const char *, const char *);
-int git_config_system(void);
+int git_config_system(const struct config_options *opts);
 int config_error_nonbool(const char *);
 #if defined(__GNUC__)
 #define config_error_nonbool(s) (config_error_nonbool(s), const_error())

@@ -2437,6 +2437,110 @@ test_expect_success 'list --global with nonexistent global config fails' '
 	test_must_fail git config ${mode_prefix}list --global --show-scope
 '
 
+test_expect_success 'list and get --global with only home' '
+	rm -f "$HOME"/.config/git/config &&
+
+	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
+	cat >"$HOME"/.gitconfig <<-EOF &&
+	[home]
+		config = true
+	EOF
+
+	cat >expect <<-EOF &&
+	global	home.config=true
+	EOF
+	git config ${mode_prefix}list --global --show-scope >actual &&
+	test_cmp expect actual &&
+
+	echo true >expect &&
+	git config ${mode_get} --global home.config >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'list and get --global with only xdg' '
+	rm -f "$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 >actual &&
+	test_cmp expect actual &&
+
+	echo true >expect &&
+	git config ${mode_get} --global xdg.config >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'list and get --global with both home and xdg' '
+	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
+	cat >"$HOME"/.gitconfig <<-EOF &&
+	[home]
+		config = home
+	EOF
+
+	test_when_finished rm -rf \"\$HOME\"/.config/git &&
+	mkdir -p "$HOME"/.config/git &&
+	cat >"$HOME"/.config/git/config <<-EOF &&
+	[xdg]
+		config = xdg
+	EOF
+
+	cat >expect <<-EOF &&
+	global	file:$HOME/.config/git/config	xdg.config=xdg
+	global	file:$HOME/.gitconfig	home.config=home
+	EOF
+	# Git uses HOME and XDG_CONFIG_HOME to determine the location of the
+	# XDG config file. On Windows, the default values lead to mixed forward
+	# and backward slashes in the output --show-origin path for XDG config.
+	# Explicitly set XDG_CONFIG_HOME with only forward slashes, allowing us
+	# to use the same expected path across all platforms.
+	XDG_CONFIG_HOME="$HOME/.config" \
+		git config ${mode_prefix}list --global \
+		--show-scope --show-origin >actual &&
+	test_cmp expect actual &&
+
+	echo xdg >expect &&
+	git config ${mode_get} --global xdg.config >actual &&
+	test_cmp expect actual &&
+
+	echo home >expect &&
+	git config ${mode_get} --global home.config >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'list --global ignores other scopes' '
+	test_when_finished rm -f system_config &&
+	cat >system_config <<-EOF &&
+	[system]
+		config = true
+	EOF
+
+	test_config core.repositoryformatversion 1 &&
+	test_config extensions.worktreeConfig true &&
+	test_config --worktree worktree.config true &&
+
+	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
+	cat >"$HOME"/.gitconfig <<-EOF &&
+	[home]
+		config = home
+	EOF
+
+	test_config repo.config true &&
+
+	echo "global	home.config=home" >expect &&
+	GIT_CONFIG_NOSYSTEM=false GIT_CONFIG_SYSTEM=system_config \
+		git -c cmdline.config=true config ${mode_prefix}list \
+		--global --show-scope >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'override global and system config' '
 	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
 	cat >"$HOME"/.gitconfig <<-EOF &&

@@ -52,6 +52,8 @@ test_expect_success 'read with --get: xdg file exists and ~/.gitconfig exists' '
 	echo "	name = read_gitconfig" >>.gitconfig &&
 	echo read_gitconfig >expected &&
 	git config --get user.name >actual &&
+	test_cmp expected actual &&
+	git config --global --get user.name >actual &&
 	test_cmp expected actual
 '
 

@@ -68,7 +70,8 @@ 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
 '