PHP Deprecated: trim(): Passing null to parameter #1 ($string) of type string is deprecated

[peti123x]

Problem description

Using the latest PHP8.2 image and the latest version of phpmailer (6.8.1), I'm getting a deprecation warning pointing to https://github.com/PHPMailer/PHPMailer/blob/master/src/PHPMailer.php#L1574 (the trim() function gets a null value).

Code to reproduce

Not sure what in the system is actually making the deprecation warning emit, but nevertheless the fact that the warning appears means the trimmed value can be null.

Debug output

[Synchro]

This is a little mysterious because all of From, Sender, and ConfirmReadingTo are initialised to empty strings, and nowhere are any of them set to null. However, they are public properties that can be set to null by calling code, which I assume is what's happening for you. I'm not too concerned about that, but I'll accept a PR if you want to catch that scenario.

[Synchro]

This is fixed in the main branch and will be in the next release