Merge branch 'jn/warn-on-inaccessible-loosen' into maint

When attempting to read the XDG-style $HOME/.config/git/config and
finding that $HOME/.config/git is a file, we gave a wrong error
message, instead of treating the case as "a custom config file does
not exist there" and moving on.

* jn/warn-on-inaccessible-loosen:
  config: exit on error accessing any config file
  doc: advertise GIT_CONFIG_NOSYSTEM
  config: treat user and xdg config permission problems as errors
  config, gitignore: failure to access with ENOTDIR is ok

Documentation/git-config.txt

@@ -240,6 +240,10 @@ GIT_CONFIG::
 	Using the "--global" option forces this to ~/.gitconfig. Using the
 	"--system" option forces this to $(prefix)/etc/gitconfig.
 
+GIT_CONFIG_NOSYSTEM::
+	Whether to skip reading settings from the system-wide
+	$(prefix)/etc/gitconfig file. See linkgit:git[1] for details.
+
 See also <<FILES>>.
 
 

Documentation/git.txt

@@ -772,6 +772,14 @@ for further details.
 	and read the password from its STDOUT. See also the 'core.askpass'
 	option in linkgit:git-config[1].
 
+'GIT_CONFIG_NOSYSTEM'::
+	Whether to skip reading settings from the system-wide
+	`$(prefix)/etc/gitconfig` file.  This environment variable can
+	be used along with `$HOME` and `$XDG_CONFIG_HOME` to create a
+	predictable environment for a picky script, or you can set it
+	temporarily to avoid using a buggy `/etc/gitconfig` file while
+	waiting for someone with sufficient permissions to fix it.
+
 'GIT_FLUSH'::
 	If this environment variable is set to "1", then commands such
 	as 'git blame' (in incremental mode), 'git rev-list', 'git log',

config.c

@@ -58,7 +58,7 @@ static int handle_path_include(const char *path, struct config_include_data *inc
 		path = buf.buf;
 	}
 
-	if (!access_or_warn(path, R_OK)) {
+	if (!access_or_die(path, R_OK)) {
 		if (++inc->depth > MAX_INCLUDE_DEPTH)
 			die(include_depth_advice, MAX_INCLUDE_DEPTH, path,
 			    cf && cf->name ? cf->name : "the command line");
@@ -938,23 +938,23 @@ int git_config_early(config_fn_t fn, void *data, const char *repo_config)
 
 	home_config_paths(&user_config, &xdg_config, "config");
 
-	if (git_config_system() && !access_or_warn(git_etc_gitconfig(), R_OK)) {
+	if (git_config_system() && !access_or_die(git_etc_gitconfig(), R_OK)) {
 		ret += git_config_from_file(fn, git_etc_gitconfig(),
 					    data);
 		found += 1;
 	}
 
-	if (xdg_config && !access_or_warn(xdg_config, R_OK)) {
+	if (xdg_config && !access_or_die(xdg_config, R_OK)) {
 		ret += git_config_from_file(fn, xdg_config, data);
 		found += 1;
 	}
 
-	if (user_config && !access_or_warn(user_config, R_OK)) {
+	if (user_config && !access_or_die(user_config, R_OK)) {
 		ret += git_config_from_file(fn, user_config, data);
 		found += 1;
 	}
 
-	if (repo_config && !access_or_warn(repo_config, R_OK)) {
+	if (repo_config && !access_or_die(repo_config, R_OK)) {
 		ret += git_config_from_file(fn, repo_config, data);
 		found += 1;
 	}

git-compat-util.h

@@ -637,8 +637,12 @@ int rmdir_or_warn(const char *path);
  */
 int remove_or_warn(unsigned int mode, const char *path);
 
-/* Call access(2), but warn for any error besides ENOENT. */
+/*
+ * Call access(2), but warn for any error except "missing file"
+ * (ENOENT or ENOTDIR).
+ */
 int access_or_warn(const char *path, int mode);
+int access_or_die(const char *path, int mode);
 
 /* Warn on an inaccessible file that ought to be accessible */
 void warn_on_inaccessible(const char *path);

wrapper.c

@@ -411,11 +411,19 @@ void warn_on_inaccessible(const char *path)
 int access_or_warn(const char *path, int mode)
 {
 	int ret = access(path, mode);
-	if (ret && errno != ENOENT)
+	if (ret && errno != ENOENT && errno != ENOTDIR)
 		warn_on_inaccessible(path);
 	return ret;
 }
 
+int access_or_die(const char *path, int mode)
+{
+	int ret = access(path, mode);
+	if (ret && errno != ENOENT && errno != ENOTDIR)
+		die_errno(_("unable to access '%s'"), path);
+	return ret;
+}
+
 struct passwd *xgetpwuid_self(void)
 {
 	struct passwd *pw;