mailchimp extension error, php 7.1, civi 5.10.4, drupal 7.x

Question

with civi 5.10.4, Drupal 7.x and php 7.1 there is a warning that in some cases turns into a fatal error that will prevent the webhooks from working

Declaration of CRM_Mailchimp_Permission::check($permissions) should be compatible with CRM_Core_Permission::check($permissions, $contactId = NULL) in /path/to/uk.co.vedaconsulting.mailchimp-2.0.1/CRM/Mailchimp/Permission.php

CiviVolunteer had a similar issue, following the example in that fix I was able to get mailchimp extension working. https://github.com/civicrm/org.civicrm.volunteer/pull/477/files

I'll submit a pull request soon but in the meantime if anyone is having the same issue the fix is

remove: class CRM_Mailchimp_Permission extends CRM_Core_Permission {

add: class CRM_Mailchimp_Permission {

and

remove: return parent::check($permissions);

add: return CRM_Core_Permission::check($permissions,NULL);

if interested, issue in the extension's github is https://github.com/veda-consulting/uk.co.vedaconsulting.mailchimp/issues/319

Answer 1

patch:

index 5b82f65e..76c816dc 100644
--- a/uk.co.vedaconsulting.mailchimp-2.0.1/CRM/Mailchimp/Permission.php
+++ b/uk.co.vedaconsulting.mailchimp-2.0.1/CRM/Mailchimp/Permission.php
@@ -1,6 +1,6 @@
 <?php

-class CRM_Mailchimp_Permission extends CRM_Core_Permission {
+class CRM_Mailchimp_Permission {

   /**
    * Returns an array of permissions defined by this extension. Modeled off of
@@ -35,6 +35,6 @@ class CRM_Mailchimp_Permission extends CRM_Core_Permission {
         }
       });
     }
-    return parent::check($permissions);
+    return CRM_Core_Permission::check($permissions,NULL);
   }
 }