Event Registration: initialize array

[mlutfy]

Overview

Minor code nitpick to avoid a PHP fatal on PHP 8.0 in certain unusual circumstances.

Before

Viewing Event Registration page as an organization results in fatal PHP error.

After

Viewing Event Registration page as an organization displays the form, although in a not-very-supported way.

Technical Details

Under PHP 8.0, this throws a fatal error. Previously it only throw a warning:

php -r "array_intersect_key(NULL, []);"

Comments

Sure, it's not a supported use-case, and I stumbled on it by accident, but initializing variables is usually not a bad thing.

[civibot]

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[mlutfy]

jenkins, test this please

[totten]

Oof, that code has a lot of different branches for initializing $fields. But there does appear to be a gap when $contactID is trueish, $id is not an array, filterUFGroups() is falseish.

Agree this shouldn't change the current behavior - it should just make the outcome on php80 match outcome on php7x.

Tests passing. Merging.