config, gitignore: failure to access with ENOTDIR is ok

The access_or_warn() function is used to check for optional
configuration files like .gitconfig and .gitignore and warn when they
are not accessible due to a configuration issue (e.g., bad
permissions).  It is not supposed to complain when a file is simply
missing.

Noticed on a system where ~/.config/git was a file --- when the new
XDG_CONFIG_HOME support looks for ~/.config/git/config it should
ignore ~/.config/git instead of printing irritating warnings:

 $ git status -s
 warning: unable to access '/home/jrn/.config/git/config': Not a directory
 warning: unable to access '/home/jrn/.config/git/config': Not a directory
 warning: unable to access '/home/jrn/.config/git/config': Not a directory
 warning: unable to access '/home/jrn/.config/git/config': Not a directory

Compare v1.7.12.1~2^2 (attr:failure to open a .gitattributes file
is OK with ENOTDIR, 2012-09-13).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-compat-util.h

@@ -604,7 +604,10 @@ 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);
 
 /* Warn on an inaccessible file that ought to be accessible */

wrapper.c

@@ -411,7 +411,7 @@ 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;
 }