Description:
------------
NT ACL Permissions can be modified in Windows by right clicking on the file, going to properties, and security. Clicking the Everyone user and hitting Deny Read, will prevent ANYTHING from reading, even if they have  READ permissions granted elsewhere. 

is_readable() doesn't seem to care and thinks that all these files are readable, when in fact they aren't. is_writeable() probably has the same problem. Previous Bugs Identified with this have been closed: 41519.



Reproduce code:
---------------
$some_file = 'C:\\path\to\file.txt';
if(is_readable($some_file))
{
   echo file_get_contents($some_file);
} else
{
   echo "This file isn't readable";
}




Expected result:
----------------
With NTFS ACL Permissions set to allow reading:

*Contents of File*

With NTFS ACL Permissions set to disallow reading:

"This file isn't readable";



Actual result:
--------------
With NTFS ACL Permissions set to allow reading:

*Contents of File*

With NTFS ACL Permissions set to disallow reading:

Warning: file_get_contents(C:\\path\to\file.txt) [function.file-get-contents]: failed to open stream: Permission denied in C:\\path\to\script.php on line 4