It's PHP 5.2 vs PHP 5.3+ - 7 problem
Some Japanese characters collectively known as '5C' characters with 1byte coded as 5C are maltreated as backslashes by PHP, which result in failure of some important filing functions, such as file_exists, is_file, is_dir and so on...
If the path consists of these characters, all of these functions will fail under XAMPP(PHP) on Windows using Shift_JIS as the default code page for non-unicode programs (the default encoding for Jp Windows)
It's a mystery to me that how PHP 5.2 (XAMP 1.7.1) could handle these problems partially, but from 5.3? onward the problem exists in most versions of PHP.
What need to be tinkered to fix this?
Using addslash or mb_convert_encoding will NOT solve this problem. It seems to be require a more basic PHP configuration.
*partially means these functions works but some file operations could result in empty directory creations of a partial path of the original.