PHP crashes on preg_replace

I ran the following script using `php.exe`: ``` preg_replace('#(?:^[^\pL]*)|(?:[^\pL]*$)#u','',$string); ``` or its equivalent: ``` preg_replace('#(?:^[^\pL]*|[^\pL]*$)#u','',$string); ``` If `$string="S"` or `$string=" ذذ "` it works, if `string='ذ'` it yields `�` that is incorrect , and if `string='ذذ'` PHP crashes. But it works in 4.4.0 - 4.4.9, 5.0.5 - 5.1.6 versions. What is wrong ? See: http://3v4l.org/T3rpV ``` <?php $string='دد'; echo preg_replace('#(?:^[^\pL]*)|(?:[^\pL]*$)#u','',$string); ``` Output for 5.4.0 - 5.5.0alpha6 ``` Process exited with code 139. ``` Output for 5.2.0 - 5.3.22, 5.5.0beta1 Output for 4.4.0 - 4.4.9, 5.0.5 - 5.1.6 ``` دد ``` Output for 4.3.11, 5.0.0 - 5.0.4 ``` Warning: preg_replace(): Compilation failed: PCRE does not support \L, \l, \N, \P, \p, \U, \u, or \X at offset 7 in /in/T3rpV on line 3 ``` Output for 4.3.0 - 4.3.10 ``` Warning: Compilation failed: PCRE does not support \L, \l, \N, \P, \p, \U, \u, or \X at offset 7 in /in/T3rpV on line 3 ```