Signal a file-error from directory-files on MS-Windows (Bug#19701)

src/dired.c (directory_files_internal) [WINDOWSNT]: If readdir
 returns NULL and errno is ENOTDIR, behave as if opendir failed to
 open the directory.
 src/w32.c (sys_readdir): If FindFirstFile fails because the
 directory doesn't exist, set errno to ENOTDIR.

src/ChangeLog

@@ -1,3 +1,12 @@
+2015-01-27  Eli Zaretskii  <eliz@gnu.org>
+
+	* dired.c (directory_files_internal) [WINDOWSNT]: If readdir
+	returns NULL and errno is ENOTDIR, behave as if opendir failed to
+	open the directory.  (Bug#19701)
+
+	* w32.c (sys_readdir): If FindFirstFile fails because the
+	directory doesn't exist, set errno to ENOTDIR.
+
 2015-01-24  Jan Djärv  <jan.h.d@swipnet.se>
 
 	* nsterm.m (drawRect:): Add block/unblock_input (Bug#19660).

src/dired.c

@@ -247,6 +247,19 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
 	      QUIT;
 	      continue;
 	    }
+#ifdef WINDOWSNT
+	  /* The MS-Windows implementation of 'opendir' doesn't
+	     actually open a directory until the first call to
+	     'readdir'.  If 'readdir' fails to open the directory, it
+	     sets errno to ENOTDIR; we convert it here to ENOENT so
+	     that the error message is similar to what happens on
+	     Posix hosts in such cases.  */
+	  if (errno == ENOTDIR)
+	    {
+	      errno = ENOENT;
+	      report_file_error ("Opening directory", directory);
+	    }
+#endif
 	  break;
 	}
 

src/w32.c

@@ -3432,7 +3432,22 @@ sys_readdir (DIR *dirp)
 	}
 
       if (dir_find_handle == INVALID_HANDLE_VALUE)
-	return NULL;
+	{
+	  switch (GetLastError ())
+	    {
+	    case ERROR_PATH_NOT_FOUND:
+	    case ERROR_ACCESS_DENIED:
+	    case ERROR_INVALID_DRIVE:
+	    case ERROR_BAD_NETPATH:
+	      /* This special value will be noticed by
+		 directory_files_internal, which see.  */
+	      errno = ENOTDIR;
+	      break;
+	    default:
+	      break;
+	    }
+	  return NULL;
+	}
     }
   else if (w32_unicode_filenames)
     {