bugfix (#4306)

Author: jobjen02

src/Files/Disk.php

@@ -68,6 +68,10 @@ public function copy(TemporaryFile $source, string $destination): bool
     {
         $readStream = $source->readStream();
 
+        if (!is_resource($readStream)) {
+            return false;
+        }
+
         if (realpath($destination)) {
             $tempStream = fopen($destination, 'rb+');
             $success    = stream_copy_to_stream($readStream, $tempStream) !== false;