new DateTimeZone('Etc/GMT+9') fails with fatal error since 8.1.14

[nicolas-grekas]

Description

The following code (see https://3v4l.org/lfalF):

var_dump(date_default_timezone_set('Etc/GMT+9'));

$d = new DateTime();

var_dump($d->getTimeZone());

new DateTimeZone('Etc/GMT+9');

Resulted in this output:

Fatal error: Uncaught Exception: DateTimeZone::__construct(): Unknown or bad timezone (Etc/GMT+9)

But I expected this output instead:

no error

As highlighted by the code sample, it's possible to create such a DateTimeZone object via DateTime::getTimeZone.

PHP Version

PHP 8.1.14+

Operating System

No response

[derickr]

Duplicate of #10218, which I fixed yesterday.

Please do note that using these Etc/GMT+7 style time zones should be avoid, as the +7 really means UTC-7, and they're also listed on the "avoid these please" in the manual: https://www.php.net/manual/en/timezones.others.php — you should make sure that users also can't easily select these.