commit 59b8184b7b1ef00c8419314d8f38064881704ede
Author: beejeebus <justin.p.randell@gmail.com>
Date:   Sun Jan 6 21:29:47 2019 +0000

    Only copy or move, not move and copy.

diff --git a/core/modules/migrate/src/Plugin/migrate/process/FileCopy.php b/core/modules/migrate/src/Plugin/migrate/process/FileCopy.php
index d0d8d02054..33b3959ba2 100644
--- a/core/modules/migrate/src/Plugin/migrate/process/FileCopy.php
+++ b/core/modules/migrate/src/Plugin/migrate/process/FileCopy.php
@@ -182,7 +182,9 @@ protected function writeFile($source, $destination, $replace = FileSystemInterfa
       if ($this->configuration['move']) {
         $this->fileSystem->move($source, $destination, $replace);
       }
-      $this->fileSystem->copy($source, $destination, $replace);
+      else {
+        $this->fileSystem->copy($source, $destination, $replace);
+      }
       return $destination;
     }
     catch (FileException $e) {