Description:
------------
What this code should do, is to take the $lines array and delete the 2B value, but it doesn’t work like that, and is because it get crash when you use the $items variable in the second foreach and you already used it as a referece variable, even if you clean the $items variable with an empty array as you see in the code.

Just if you change the name or the $items variable in the second foreach it works fine.

Test script:
---------------
$lines = array(
	'1' => array(
		'1A'
	),
	'2' => array(
		'2A',
		'2B',
		'2C'
	)
);

foreach($lines as &$items){
	foreach($items as $key => $value){
		if($value=='2B') unset($items[$key]);
	}
}

$items = array();
foreach($lines as $key => $items){
	print_r($items);
}

Expected result:
----------------
array(
		'1A'
)
array(
		'2A',
		'2C'
	)


Actual result:
--------------
array(
		'1A'
)
array(
		'1A'
)