Array Data Address Reference Issue

[uuur86]

Description

When I try to create a new record inside a RecursiveArrayIterator Object using offsetSet method, the previously specified address reference is cancelled and I lose the connection with the object.

The following code:

<?php
use Iterator;
use Traversable;
use RecursiveArrayIterator;
use JsonSerializable;

use RecursiveIterator;

interface DataInterface extends JsonSerializable, RecursiveIterator, Iterator
{
    /**
     * @param mixed $data
     *
     * @return DataInterface
     */
    public static function init(Traversable $data): DataInterface;
}


class A extends RecursiveArrayIterator implements DataInterface
{
    public function __construct($data)
    {
        parent::__construct($data);
    }
    
    public static function init($data): DataInterface
    {
        return new static($data);
    }
    
    public function getCols(string $colname): array
    {
        return array_column($this->getArrayCopy(), $colname);
    }
    
    public function bugySetMethod($key, $value)
    {
        $data = &$this;

        while ($data->hasChildren()) {
            $data = $data->getChildren();
        }
        
        $data->offsetSet($key, $value);
    }
    
    public function jsonSerialize()
    {
        return $this;
    }
}

$example = A::init([
    'test' => [
        'a' => (object)[2 => '',3 => '',4 => ''],
    ]
]);

$example->bugySetMethod(5, 'in here');
var_dump(json_encode($example));

// result
// string(51) "{"test":{"a":{"2":"","3":"","4":"","5":"in here"}}}"

$example = A::init([
    'test' => [
        'b' => [2 => '',3 => '',4 => ''],
    ]
]);

$example->bugySetMethod(5, 'must be here');
var_dump(json_encode($example));

// result
// string(37) "{"test":{"b":{"2":"","3":"","4":""}}}"

Resulted in this output:

string(37) "{"test":{"b":{"2":"","3":"","4":""}}}"

But I expected this output instead:

string(37) "{"test":{"b":{"2":"","3":"","4":"","5":"must be here"}}}"

PHP Version

Operating System

[Girgias]

I think I've figured out the issue:

The default behaviour of RecursiveArrayIterator::getChildren()

php-src/ext/spl/spl_array.c

Lines 1487 to 1498 in c8ec2ed

	ZVAL_DEREF(entry);
	if (Z_TYPE_P(entry) == IS_OBJECT) {
	if ((intern->ar_flags & SPL_ARRAY_CHILD_ARRAYS_ONLY) != 0) {
	RETURN_NULL();
	}
	if (instanceof_function(Z_OBJCE_P(entry), Z_OBJCE_P(ZEND_THIS))) {
	RETURN_OBJ_COPY(Z_OBJ_P(entry));
	}
	}
	ZVAL_LONG(&flags, intern->ar_flags);
	spl_instantiate_arg_ex2(Z_OBJCE_P(ZEND_THIS), return_value, entry, &flags);

is to return a new object for arrays.

Not sure exactly how to fix this but replacing the array entry with an instance of ArrayIterator might be sensible? @cmb69 what's your opinion?