Bug in WPForms Integration – array_merge() TypeError in class-field.php

Hi,

I’m experiencing a fatal error when using the Mailchimp for WP and WPForms integration. The issue occurs in /wp-content/plugins/mailchimp-for-wp/integrations/wpforms/class-field.php on line 196 and seems to be caused by an array_merge() function trying to merge a null value.Error Message:

Fatal error: Uncaught TypeError: array_merge(): Argument #2 must be of type array, null given in /wp-content/plugins/mailchimp-for-wp/integrations/wpforms/class-field.php:196

It looks like $field_atts is sometimes null, which causes this issue in PHP 8+.

Suggested Fix:

To prevent this error, I updated the code on line 196 to ensure $field_atts is always treated as an array:

Original Code:

$field_atts = array_merge([
    'input_class' => [],
    'input_id' => [],
], $field_atts);

Fixed Code:

$field_atts = array_merge([
    'input_class' => [],
    'input_id' => [],
], is_array($field_atts) ? $field_atts : []);

This change ensures $field_atts is always an array, preventing the TypeError.

Could you confirm if this is a valid fix and whether an official update will include it? Let me know if you need any additional details.

Thanks!