SCP: do $var === false vs !$var

phpseclib/Net/SCP.php

@@ -283,6 +283,13 @@ class Net_SCP
         $content = '';
         while ($size < $info['size']) {
             $data = $this->_receive();
+
+            // Terminate the loop in case the server repeatedly sends an empty response
+            if ($data === false) {
+                user_error('No data received from server', E_USER_NOTICE);
+                return false;
+            }
+
             // SCP usually seems to split stuff out into 16k chunks
             $size+= strlen($data);