An example to demonstrate https://github.com/symphonycms/symphony-2/issues/2742

2742.php

<?php

/*
Some extension.
*/
function delegate(array $context)
{
    if (!isset($context['section_ids'])) {
        return;
    }
    if (!is_array($context['section_ids'])) {
        return;
    }

    /*
    Things an extension could do with the array...
    */
    unset($context['section_ids'][0]);

    $context['section_ids'][] = 5;
    $context['section_ids'][] = 42;
}

/*
Symphony core 2.7.0.
*/
$section_id  = 23;
$section_ids = [ $section_id ];

delegate([ 'section_ids' => &$section_ids ]);

foreach ($section_ids as $section_id) {
    echo $section_id . PHP_EOL;
}

echo PHP_EOL;

/*
Proposed patch.
*/
$section_id  = 23;

delegate([ 'section_ids' => [ &$section_id ] ]);

echo $section_id . PHP_EOL;