config: read both home and xdg config in list --global [do not submit]

builtin/config.c

@@ -768,7 +768,16 @@ static void location_options_init(struct config_location_options *opts,
 	}
 
 	if (opts->use_global_config) {
+		// Used for reading config:
+		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;
+
+		// Used for writing config:
 		opts->source.file = opts->file_to_free = git_global_config();
+		// todo(delilahwu): Do we need to move this error handling somewhere else?
 		if (!opts->source.file)
 			/*
 			 * It is unknown if HOME/.gitconfig exists, so
@@ -833,6 +842,22 @@ static void display_options_init(struct config_display_options *opts)
 	}
 }
 
+static void handle_nonzero_config_with_options(const struct config_location_options
+						       *location_opts)
+{
+	// todo(delilahwu): Either un-refactor this back to its original state from
+	// `master` or clean it up.
+	const char *err_file = location_opts->source.file; /* ?
+				       location_opts->source.file :
+			       location_opts->source.user_config ?
+				       location_opts->source.user_config :
+				       NULL; */
+	if (err_file)
+		die_errno(_("unable to read config file '%s'"), err_file);
+	else
+		die(_("error processing config file(s)"));
+}
+
 static int cmd_config_list(int argc, const char **argv, const char *prefix,
 			   struct repository *repo UNUSED)
 {
@@ -858,11 +883,7 @@ static int cmd_config_list(int argc, const char **argv, const char *prefix,
 	if (config_with_options(show_all_config, &display_opts,
 				&location_opts.source, the_repository,
 				&location_opts.options) < 0) {
-		if (location_opts.source.file)
-			die_errno(_("unable to read config file '%s'"),
-				  location_opts.source.file);
-		else
-			die(_("error processing config file(s)"));
+		handle_nonzero_config_with_options(&location_opts);
 	}
 
 	location_options_release(&location_opts);
@@ -1282,11 +1303,7 @@ static int cmd_config_actions(int argc, const char **argv, const char *prefix)
 		if (config_with_options(show_all_config, &display_opts,
 					&location_opts.source, the_repository,
 					&location_opts.options) < 0) {
-			if (location_opts.source.file)
-				die_errno(_("unable to read config file '%s'"),
-					  location_opts.source.file);
-			else
-				die(_("error processing config file(s)"));
+			handle_nonzero_config_with_options(&location_opts);
 		}
 	}
 	else if (actions == ACTION_EDIT) {

config.c

@@ -2019,11 +2019,13 @@ 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 access_success_count = 0;
+	int nonzero_ret_on_global_access_error = scope == CONFIG_SCOPE_GLOBAL;
 	char *xdg_config = NULL;
 	char *user_config = NULL;
 	char *repo_config;
@@ -2045,22 +2047,45 @@ 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 (xdg_config) {
+			if (!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_access_error && !ret) {
+					++access_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 (user_config) {
+			if (!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_access_error && !ret) {
+					++access_success_count;
+				}
+			}
+		}
+
+		if (nonzero_ret_on_global_access_error && !access_success_count) {
+			--ret;
+		}
+
+		free(xdg_config);
+		free(user_config);
+	}
 
 	if (!opts->ignore_repo && repo_config &&
 	    !access_or_die(repo_config, R_OK, 0))
@@ -2079,8 +2104,6 @@ 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;
@@ -2110,15 +2133,19 @@ 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; // From /etc/gitconfig
+	unsigned int ignore_global : 1; // From a combination of `~/.gitconfig` and `XDG_CONFIG_HOME/git/config`
 	unsigned int ignore_repo : 1;
 	unsigned int ignore_worktree : 1;
 	unsigned int ignore_cmdline : 1;

flake.nix

@@ -0,0 +1,41 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        overlays = [ ];
+        pkgs = import nixpkgs {
+          inherit system overlays;
+        };
+      in
+      with pkgs;
+      {
+        devShell = mkShell {
+          buildInputs = [
+            # Build tools
+            autoconf
+            clang-tools_19
+            clang_19
+            cmake
+            ninja
+            perl
+            lldb_19
+
+            # Deps
+            curl
+            zlib
+            expat
+          ];
+        };
+      }
+    );
+}

t/t1300-config.sh

@@ -2367,6 +2367,76 @@ test_expect_success '--show-scope with --default' '
 	test_cmp expect actual
 '
 
+test_expect_success 'list with nonexistent global config' '
+	rm -rf "$HOME"/.config/git/config &&
+	rm -f .git/config &&
+	git config ${mode_prefix}list --show-scope
+'
+
+test_expect_success 'list --global with nonexistent global config' '
+	rm -rf "$HOME"/.config/git/config &&
+	rm -f .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 &&
+	rm -f .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 .git/config &&
+
+	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 ${mode_prefix}list --global --show-scope >output &&
+	test_cmp expect output
+'
+
+test_expect_success 'list --global with both home and xdg' '
+	rm -f .git/config &&
+
+	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
+	cat >"$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 &&