Description:
------------
I was under the impression that \w matches any word character, as in a-z, A-Z, 0-9 and _ characters (documentation also says "some character codes greater than 128 are used for accented letters, and these are matched by \w" if a specific code page is used but it's not the case here, it's a default PHP installation).

However, I have noticed the following issue and I'm not sure if it's a bug in PHP or an error in the way I've written the regular expression in the code below. As I understood regular expressions work, the code below should not return any match but it does.



Reproduce code:
---------------
$text = 'start://abcd'.chr(255).chr(255).'efgh';

$results = preg_match_all('/(start:\/\/|finish:\/\/){1}([\w\x3A - \x40]*)$/is',$text,$matches,PREG_OFFSET_CAPTURE);
var_dump($results,$matches);

Expected result:
----------------
The could above should return no matches. If the $ at the end is omitted, I think it should return "start://abcd". Replacing \w with 0-9a-zA-Z_ produces the correct output.

Actual result:
--------------
Output of the above code:

int(1)
array(3) {
  [0]=>
  array(1) {
    [0]=>
    array(2) {
      [0]=>
      string(18) "start://abcd��efgh"
      [1]=>
      int(0)
    }
  }
  [1]=>
  array(1) {
    [0]=>
    array(2) {
      [0]=>
      string(8) "start://"
      [1]=>
      int(0)
    }
  }
  [2]=>
  array(1) {
    [0]=>
    array(2) {
      [0]=>
      string(10) "abcd��efgh"
      [1]=>
      int(8)
    }
  }
}