Description:
------------
While I was writing tests to improve test coverage I've found an error with UConverter::setDestinationEncoding ( http://php.net/manual/fr/uconverter.setdestinationencoding.php ).

setDestinationEncoding() changes the source encoding instead of the destination encoding.

Test script:
---------------
<?php

$utf8 = UConverter::getAliases('utf-8')[0];
$utf16 = UConverter::getAliases('utf-16')[0];
$utf32 = UConverter::getAliases('utf-32')[0];
$latin1 = UConverter::getAliases('latin1')[0];

function printResult($actual, $expected) {
    var_dump($actual === $expected ? true : "expected: $expected, actual: $actual");
}

// test default values
$c = new UConverter();
printResult($c->getDestinationEncoding(), $utf8);
printResult($c->getSourceEncoding(), $utf8);

// test constructor args
$c = new UConverter('utf-16', 'latin1');
printResult($c->getDestinationEncoding(), $utf16);
printResult($c->getSourceEncoding(), $latin1);

// test setters
var_dump($c->setDestinationEncoding('utf-8'));
var_dump($c->setSourceEncoding('utf-32'));
printResult($c->getDestinationEncoding(), $utf8);
printResult($c->getSourceEncoding(), $utf32);

// test invalid inputs dont change values
var_dump($c->setDestinationEncoding('foobar') === false);
var_dump($c->setSourceEncoding('foobar') === false);
printResult($c->getDestinationEncoding(), $utf8);
printResult($c->getSourceEncoding(), $utf32);

Expected result:
----------------
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)

Actual result:
--------------
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
bool(true)
string(31) "expected: UTF-8, actual: UTF-16"
bool(true)
bool(true)
bool(true)
string(31) "expected: UTF-8, actual: UTF-16"
bool(true)