Description:
------------
When the recursive subpattern is captured after it is referenced:

(?2)?::(?>((?1)(?>:(?1)){0,4}):)?

It works fine. But when the capture comes before the reference it doesn't:

((?1)(?>:(?1)){0,4})?::(?>(?2):)?

The problem is the final ":" as other characters work fine. Replacing it with "\:" 
or "[:]" does not help.

Test script:
---------------
// Test 1
preg_match('/^(?>([a-f0-9]{1,4})(?>:(?1)){5}:|(?!(?:.*[a-f0-9]:){6,})(?2)?::(?>((?1)(?>:(?1)){0,4}):)?)(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?3)){3}$/iD', '0:0:0:0::0:255.255.255.255');

// Test 2
preg_match('/^(?>([a-f0-9]{1,4})(?>:(?1)){5}:|(?!(?:.*[a-f0-9]:){6,})((?1)(?>:(?1)){0,4})?::(?>(?2):)?)(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?3)){3}$/iD', '0:0:0:0::0:255.255.255.255');

// Test 3
preg_match('/^(?>([a-f0-9]{1,4})(?>:(?1)){5}:|(?!(?:.*[a-f0-9]:){6,})((?1)(?>:(?1)){0,4})?::(?>(?2)!)?)(25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])(?>\.(?3)){3}$/iD', '0:0:0:0::0!255.255.255.255');

Expected result:
----------------
// Test 1
int(1)

// Test 2
int(1)

// Test 3
int(1)

Actual result:
--------------
// Test 1
int(1)

// Test 2
int(0)

// Test 3
int(1)