Description:
------------
When creating a symlink in Windows to an absolute path with a lower case drive letter, PHP will not resolve the canonicalized absolute pathname (realpath) correctly. 

This is obvious when you have nested symlinks.

When you run realpath of a nested symlink it returns the next symlink it links to, rather than the top absolute pathname.

On Linux it works correctly.

One work around that can be used is:

$link = 'f:\link3';
do {
    $link = realpath($link);
} while (realpath($link) !== false && $link !== realpath($link));

Test script:
---------------
Windows test:
F:\>mkdir target
F:\>mklink /D link1 f:\target
F:\>mklink /D link2 f:\link1
F:\>mklink /D link3 f:\link2
F:\>php -r "var_dump(realpath('link3'));"

Linux test:
$ mkdir target
$ ln -s target link1
$ ln -s link1 link2
$ ln -s link2 link3
$ php -r "var_dump(realpath('link3'));"


Expected result:
----------------
Windows test:
string(9) "F:\target"

Linux test:
string(12) "/root/target"

Actual result:
--------------
Windows test:
string(9) "f:\\link2"

Linux test:
string(12) "/root/target"