Description:
------------
According to the documentation for sort(), you must use i18n_loc_set_default() for sort() with SORT_LOCALE_STRING to work in PHP6. However, i18n_loc_set_default() is an undefined function. The documentation instead refers to locale_set_default(). When setting the locale to "sv_SE" (correct) the function returns false, but when setting it to "sv_PHP" (incorrect) the function returns true which is the wrong behavior. The example from locale_set_default() uses "pt_PT" which can be set, but when sorting the result turns out the wrong way. When using locale_get_default() it returns what was set with locale_set_default() even if that function turned it down by returning false.
When later using sort() or asort() (or any other sort) with SORT_LOCALE_STRING the result is the same as a normal sort.

Reproduce code:
---------------
<?php
//Code from the documentation for locale_set_default()

// the list of the strings to sort
$array = array(
    'caramelo',
    'cacto',
    'ca?ada'
);

// set our locale (Portuguese, in this case)
locale_set_default('pt_PT');

// sort using the locale we previously set
sort($array, SORT_LOCALE_STRING);

print_r($array);
?>

Expected result:
----------------
Array
(
    [0] => ca?ada
    [1] => cacto
    [2] => caramelo
)

Actual result:
--------------
Array
(
    [0] => cacto
    [1] => caramelo
    [2] => ca?ada
)