Adding a duplicate part to a message should not be permitted

[jamesshaw1987]

Bug Report

Q	A
Version(s)	2.9.0

Summary

The change to use a strict comparison in \Laminas\Mime\Message::addPart (if ($part === $row) {) means that the given $part can contain the exact same data as the existing $row, but an exception will only be throw if they're the same instance. It shouldn't be possible to add two parts containing identical data.

How to reproduce

$part1 = (new \Laminas\Mime\Part('DATA'))->setId('ID');
$part2 = (new \Laminas\Mime\Part('DATA'))->setId('ID');

$message = new \Laminas\Mime\Message();
$message->addPart($part1);
$message->addPart($part2); // should throw \Laminas\Mime\Exception\InvalidArgumentException with message 'Provided part ID already defined.'

Workaround

For now, this can easily be worked around by doing something like:

$message = new \Laminas\Mime\Message();
$message->addPart($part1);

if (in_array($part1, $message->getParts())) {
    return;
}

$message->addPart($part2); 

[laminas-bot]

This package is considered feature-complete, and is now in security-only maintenance mode, following a decision by the Technical Steering Committee.
If you have a security issue, please follow our security reporting guidelines.
If you wish to take on the role of maintainer, please nominate yourself

If you are looking for an actively maintained package alternative, we recommend:

• symfony/mime

[gsteel]

This library is being abandoned: https://github.com/laminas/technical-steering-committee/blob/main/meetings/minutes/2023-12-04-TSC-Minutes.md