Issue #3512551 by mrconnerton: prepareRow can't delete item from queue

src/Plugin/migrate/source/Queue.php

@@ -84,6 +84,11 @@ class Queue extends SourcePluginBase implements ContainerFactoryPluginInterface
     // Determine if the row needs processing.
     $processRow = parent::prepareRow($row);
 
+    // Restore the non-field values to the source.
+    foreach ($nonFieldNames as $nonDataKey) {
+      $row->setSourceProperty($nonDataKey, $nonFieldValues[$nonDataKey]);
+    }
+
     // If processing is not necessary, delete the item from the queue.
     if ($processRow === FALSE || !$this->needsProcessing($row)) {
       $queue = $this->queueFactory->get($row->get('queue_name'));
@@ -91,11 +96,6 @@ class Queue extends SourcePluginBase implements ContainerFactoryPluginInterface
       $queue->deleteItem($item);
     }
 
-    // Restore the non-field values to the source.
-    foreach ($nonFieldNames as $nonDataKey) {
-      $row->setSourceProperty($nonDataKey, $nonFieldValues[$nonDataKey]);
-    }
-
     return $processRow;
   }