Issue #3502753 by balazswmann: Call to undefined method ::isSyncing() during...

Issue #3502753 by balazswmann: Call to undefined method ::isSyncing() during push on certain entities

modules/salesforce_push/salesforce_push.module

@@ -6,6 +6,7 @@
  */
 
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\SynchronizableInterface;
 use Drupal\salesforce\Event\SalesforceErrorEvent;
 use Drupal\salesforce\Event\SalesforceEvents;
 use Drupal\salesforce_mapping\Entity\MappedObject;
@@ -47,9 +48,11 @@ function salesforce_push_entity_delete(EntityInterface $entity) {
  */
 function salesforce_push_entity_crud(EntityInterface $entity, $op) {
   // Don't allow mapped objects or mappings to be pushed!
-  if ($entity->isSyncing()
-  || $entity instanceof MappedObjectInterface
-  || $entity instanceof SalesforceMappingInterface) {
+  if ($entity instanceof MappedObjectInterface || $entity instanceof SalesforceMappingInterface) {
+    return;
+  }
+  // Do not push entities which are synchronizing currently.
+  if ($entity instanceof SynchronizableInterface && $entity->isSyncing()) {
     return;
   }