Fix civicrm-core/#4553 getBillingEmail() function

CRM/Core/Payment/MJWTrait.php

@@ -47,24 +47,21 @@ trait CRM_Core_Payment_MJWTrait {
   /**
    * Get the billing email address
    *
-   * @param \Civi\Payment\PropertyBag|array $params
+   * @param \Civi\Payment\PropertyBag|array $propertyBag
    * @param int $contactID
    *
-   * @return string|NULL
+   * @return string
    */
-  public function getBillingEmail($propertyBag, $contactID = NULL) {
+  public function getBillingEmail($propertyBag, $contactID = NULL): string {
     // We want this function to take a single argument - propertyBag but for legacy compatibility
     //   we still accept an array and the second parameter contactID.
-    // Start: Hackery to convert this function to take propertyBag
     $propertyBag = PropertyBag::cast($propertyBag);
     if (empty($contactID) && $propertyBag->has('contactID')) {
       $contactID = $propertyBag->getContactID();
     }
-    $params = $this->getPropertyBagAsArray($propertyBag);
-    // End: Hackery to convert this function to take propertyBag
-
-    $billingLocationId = CRM_Core_BAO_LocationType::getBilling();
-    $emailAddress = $params["email-{$billingLocationId}"] ?? $params['email-Primary'] ?? $params['email'] ?? NULL;
+    if ($propertyBag->has('email')) {
+      $emailAddress = $propertyBag->getEmail();
+    }
 
     if (empty($emailAddress) && !empty($contactID)) {
       // Try and retrieve an email address from Contact ID
@@ -73,6 +70,7 @@ trait CRM_Core_Payment_MJWTrait {
         ->execute();
 
       $other_options = [];
+      $billingLocationId = CRM_Core_BAO_LocationType::getBilling();
       foreach ($emailAddresses as $row) {
         if ($row['location_type_id'] == $billingLocationId) {
           return $row['email'];
@@ -85,11 +83,10 @@ trait CRM_Core_Payment_MJWTrait {
         }
       }
       if ($other_options) {
-        return $other_options[0];
+        $emailAddress = $other_options[0];
       }
-      return NULL;
     }
-    return $emailAddress;
+    return $emailAddress ?? '';
   }
 
   /**