[PATCH v2 2/3] config: let sequence require a successful file

From: Delilah Ashley Wu <[email protected]>

Teach `do_git_config_sequence()` to optionally report an error if no
configuration files in the sequence were successfully processed. Gate
this new behaviour with a flag and keep it disabled for now.

Add tests to record existing behaviour and prevent regressions in the
next patch, "config: read global scope via config_sequence", which adds
a code path that enables the flag. When no global configuration file
exists, `git config list` succeeds whereas `git config list --global`
fails. The command output is irrelevant, so only check the exit code.

Signed-off-by: Delilah Ashley Wu <[email protected]>
---
 config.c          | 57 ++++++++++++++++++++++++++++++++++++++-----------------
 t/t1300-config.sh | 12 ++++++++++++
 2 files changed, 52 insertions(+), 17 deletions(-)

diff --git a/config.c b/config.c
index 1bdd702e7a..4c958f46bf 100644
--- a/config.c
+++ b/config.c
@@ -1544,11 +1544,27 @@ int git_config_system(void)
 	return !git_env_bool("GIT_CONFIG_NOSYSTEM", 0);
 }
 
+static void attempt_git_config_from_file_with_options(config_fn_t fn,
+						      const char *filename,
+						      void *data,
+						      enum config_scope scope,
+						      const struct config_options *opts,
+						      int *success_count,
+						      int *cumulative_ret)
+{
+	int ret = git_config_from_file_with_options(fn, filename, data,
+						    scope, opts);
+	if (!ret)
+		(*success_count)++;
+	*cumulative_ret += ret;
+}
+
 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_successful_config)
 {
 	int ret = 0;
+	int success_count = 0;
 	char *system_config = git_system_config();
 	char *xdg_config = NULL;
 	char *user_config = NULL;
@@ -1574,32 +1590,35 @@ static int do_git_config_sequence(const struct config_options *opts,
 	if (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);
+		attempt_git_config_from_file_with_options(fn, system_config, data,
+							  CONFIG_SCOPE_SYSTEM, NULL,
+							  &success_count, &ret);
 
 	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);
+		attempt_git_config_from_file_with_options(fn, xdg_config,
+							  data,
+							  CONFIG_SCOPE_GLOBAL,
+							  NULL, &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);
+		attempt_git_config_from_file_with_options(fn, user_config,
+							  data,
+							  CONFIG_SCOPE_GLOBAL,
+							  NULL, &success_count, &ret);
 
 	if (!opts->ignore_repo && repo_config &&
 	    !access_or_die(repo_config, R_OK, 0))
-		ret += git_config_from_file_with_options(fn, repo_config, data,
-							 CONFIG_SCOPE_LOCAL, NULL);
+		attempt_git_config_from_file_with_options(fn, repo_config, data,
+							  CONFIG_SCOPE_LOCAL, NULL, &success_count, &ret);
 
 	if (!opts->ignore_worktree && worktree_config &&
 	    repo && repo->repository_format_worktree_config &&
-	    !access_or_die(worktree_config, R_OK, 0)) {
-			ret += git_config_from_file_with_options(fn, worktree_config, data,
-								 CONFIG_SCOPE_WORKTREE,
-								 NULL);
-	}
+	    !access_or_die(worktree_config, R_OK, 0))
+		attempt_git_config_from_file_with_options(fn, worktree_config, data,
+							  CONFIG_SCOPE_WORKTREE,
+							  NULL, &success_count, &ret);
 
 	if (!opts->ignore_cmdline && git_config_from_parameters(fn, data) < 0)
 		die(_("unable to parse command-line config"));
@@ -1609,6 +1628,10 @@ static int do_git_config_sequence(const struct config_options *opts,
 	free(user_config);
 	free(repo_config);
 	free(worktree_config);
+
+	if (require_successful_config && !success_count && !ret)
+		ret = -1;
+
 	return ret;
 }
 
@@ -1644,7 +1667,7 @@ 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) {
diff --git a/t/t1300-config.sh b/t/t1300-config.sh
index 329407a73d..2ce85b76ff 100755
--- a/t/t1300-config.sh
+++ b/t/t1300-config.sh
@@ -2457,6 +2457,18 @@ test_expect_success '--show-scope with --default' '
 	test_cmp expect actual
 '
 
+test_expect_success 'list with nonexistent global config gracefully exits' '
+	rm -f "$HOME"/.gitconfig "$HOME"/.config/git/config &&
+	git config ${mode_prefix}list &&
+	git config ${mode_prefix}list --show-scope
+'
+
+test_expect_success 'list --global with nonexistent global config fails' '
+	rm -f "$HOME"/.gitconfig "$HOME"/.config/git/config &&
+	test_must_fail git config ${mode_prefix}list --global &&
+	test_must_fail git config ${mode_prefix}list --global --show-scope
+'
+
 test_expect_success 'override global and system config' '
 	test_when_finished rm -f \"\$HOME\"/.gitconfig &&
 	cat >"$HOME"/.gitconfig <<-EOF &&

-- 
2.54.0