Description:
------------
If I try to handle a file whose name is ISO-8859-1 (on a NTFS file system), and force some error, the error message is printed with some unexpected chars, besides those that are to be expected when we cross different character encodings.

I tested this on PHP5.5 and it worked ok. PHP 5.6, 32 bits or 64 bits, print the strange chars and crashed a few times. I can't test this on Linux for now.

Test script:
---------------
file_get_contents (utf8_decode ('Z:/Voláção'));
echo '<br />';
trigger_error(utf8_decode ('Z:/Voláção'), E_USER_WARNING);
trigger_error(utf8_decode ('Z:/Voláção'), E_USER_WARNING);

/**
 * Note: I repeated the trigger_error() solely to prove that the output
 * is not random.
 */

Expected result:
----------------
The script should emit three very similar error messages.

Actual result:
--------------
This is what I get on my system:

  Warning: <`d��� : failed to open stream: No such file or directory [...]
  Warning: Z:/Vol���o in D:\Apache\exp\web\exp.php on line 22
  Warning: Z:/Vol���o in D:\Apache\exp\web\exp.php on line 23


The «garbage» chars are quite different in the first message. I suspect this is due to some memory corruption bug. In fact, this simple script crashes once in a while (at least on my system).