Description:
------------
When converting a stdClass object instanced by json_decode() to array, the array is aparently fine with keys properly set as seen with print_r(), but they do not work. Trying to fetch an element will result in Notice: Undefined offset.

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

    $data = [
        123 => (object)['name' => 'Example']
    ];

    print_r($data); // for reference, this shows the structure of the array $data
    echo $data[123]->name; // working as intented

    $data = json_encode($data); // serialize $data to {"123":{"name":"Example"}}

    echo "\n\n\n";

    $data = json_decode($data); // unserialize json
    $data = (array)$data; // even though it was originally an array, $data is an object because JavaScript does not support non-contiguous arrays, so we have to explicitly convert to array

    print_r($data); // this shows the structure of the array $data looks just like it was before, all should be fine, but then...

    echo $data[123]->name; // BOOM! Notice: Undefined offset: 123




Expected result:
----------------
Array
(
    [123] => stdClass Object
        (
            [name] => Example
        )

)
Example


Array
(
    [123] => stdClass Object
        (
            [name] => Example
        )

)
Example


Actual result:
--------------
Array
(
    [123] => stdClass Object
        (
            [name] => Example
        )

)
Example


Array
(
    [123] => stdClass Object
        (
            [name] => Example
        )

)
PHP Notice:  Undefined offset: 123 in test_script.php on line 19