From 665baeb949c30e974ab45683b6f688a19ca6339c Mon Sep 17 00:00:00 2001
From: Denis Chenu <courriel@shnoulle.net>
Date: Thu, 8 Nov 2018 14:59:49 +0100
Subject: [PATCH] Fixed issue #14227: Some token with existing reponse can send
 PHP Warning about seed

Dev: set a seed if empty
---
 application/libraries/MersenneTwister.php | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/application/libraries/MersenneTwister.php b/application/libraries/MersenneTwister.php
index 6889311ec8d..63ac7db939c 100644
--- a/application/libraries/MersenneTwister.php
+++ b/application/libraries/MersenneTwister.php
@@ -15,6 +15,12 @@ function setSeed($surveyid)
     if (isset($_SESSION['survey_'.$surveyid]['srid'])) {
         $oResponse = \Response::model($surveyid)->findByPk($_SESSION['survey_'.$surveyid]['srid']);
         $seed = $oResponse->seed;
+        /* fix empty seed, this allow broken seed (not number) */
+        if(empty($seed)) {
+            $seed = mt_rand();
+            $oResponse->seed = $seed;
+            $oResponse->save();
+        }
     } else {
         $seed = mt_rand();