Bug: When using empty 'regions' in s3 storage and upgrading, you'll run into issues

[twhiting9275]

Randomly ran into this one today when updating a dev site so I thought I'd open this up in here as well as a bug report

In v8, the 'region' field is not required when s3 storage is used as it shouldn't be. Not all s3 providers require, or supply it.. I upgraded a v8 dev install from v8 to v9 today, went to do a template cleanup (inside WHMCS) and got this:

InvalidArgumentException: Missing required client configuration options:
region: (string)
A "region" configuration value is required for the "s3" service
(e.g., "us-west-2"). A list of available public regions and endpoints can be
found at http://docs.aws.amazon.com/general/latest/gr/rande.html. in /home/user/public_html/vendor/aws/aws-sdk-php/src/ClientResolver.php:1280

Did some digging into ClientResolver.php, and it seems that this can no longer handle empty regions properly. In v8 this works fine, but the upgrades to v9 make this not so much

My own digging and testing came up with the following solution which works:

In ClientResolver.php, around line 1260, replace _apply_region with this code

    public static function _apply_region($value, array &$args)
    {
        if (empty($value)) {
        $value  = 'auto';
//            self::_missing_region($args);
        }
        $args['region'] = $value;
    }

Keep in mind that this is going to be very specific, so get your provider's default region if you want and replace 'auto' with that. This works with CF storage though, very well.