Add a new imap_is_open() function to check that a connection object is still valid

[Girgias]

Fixes #10051

As I can't test this locally, I've just YOLOed the implementation and hopefully CI will tell me if I did something wrong.

I'm wondering if it makes sense to backport to PHP 8.1 and 8.2 as this seems necessary and is really self-contained.
8.1 RMs: @ramsey @patrickallaert, 8.2 RMs: @adoy @saundefined

[cmb69]

Thank you! The patch is fine (also checked locally).

Regarding the branch to target: in my opinion, PHP-8.2 should be a no-brainer; if we commit soon, it will make it into php-8.2.1RC1. Targeting PHP-8.1 is up to debate, but I'm not against that either.

[adoy]

Looks good to me for 8.2
I did not packaged 8.2.1 yet. I will probably do it at the end of the day (Eastern time) so if you can merge it before.

Thanks :)

[Girgias]

Merged it as 52a891a for PHP-8.2.

Should we still wait for 8.1 RMs before closing?

[cmb69]

Should we still wait for 8.1 RMs before closing?

Good question. We still could ship this with PHP 8.1.15, but finally that's an RM decision. @ramsey, @patrickallaert, what do you think?

[ramsey]

Seems very self-contained, so I don't mind it being in PHP 8.1. @patrickallaert ?

[Girgias]

Closing this, can always re-open if it should end up in 8.1

[jabcreations]

For those encountering the error that leads your searching here I would like to point out that if you have your loops to iterate email messages written correctly you will not encounter the error and thus the need for the imap_is_open() function. I'm still happy to have it though I'm much happier to have realized that I don't need it.