From df257686c1a80a9050fd899a107bc452c666f808 Mon Sep 17 00:00:00 2001
From: Robbie Averill <robbie@silverstripe.com>
Date: Wed, 20 Jun 2018 10:41:36 +1200
Subject: [PATCH] Restore check for zero or negative transaction nesting

---
 src/ORM/Connect/MySQLDatabase.php | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/ORM/Connect/MySQLDatabase.php b/src/ORM/Connect/MySQLDatabase.php
index 0477591de..49f6dd62d 100644
--- a/src/ORM/Connect/MySQLDatabase.php
+++ b/src/ORM/Connect/MySQLDatabase.php
@@ -360,7 +360,10 @@ class MySQLDatabase extends Database
             return false;
         }
         --$this->transactionNesting;
-        $this->query('COMMIT AND ' . ($chain ? '' : 'NO ') . 'CHAIN');
+        if ($this->transactionNesting <= 0) {
+            $this->transactionNesting = 0;
+            $this->query('COMMIT AND ' . ($chain ? '' : 'NO ') . 'CHAIN');
+        }
         return true;
     }