From 9ec77ab9d3bc5b525796e223c7b8f16cb58068e8 Mon Sep 17 00:00:00 2001
From: Will Rossiter <will@fullscreen.io>
Date: Wed, 25 Jul 2018 15:05:17 +1200
Subject: [PATCH] Check database has table before altering.

Work around to prevent several issues with silverstripe-framework#4451 and cwp#0031726.

Throws a LogicException if the table does not exist.
---
 src/ORM/Connect/MySQLSchemaManager.php | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/ORM/Connect/MySQLSchemaManager.php b/src/ORM/Connect/MySQLSchemaManager.php
index 81f661ae2..c75097c4a 100644
--- a/src/ORM/Connect/MySQLSchemaManager.php
+++ b/src/ORM/Connect/MySQLSchemaManager.php
@@ -4,6 +4,7 @@ namespace SilverStripe\ORM\Connect;
 
 use SilverStripe\Core\Config\Config;
 use SilverStripe\Core\Convert;
+use LogicException;
 
 /**
  * Represents schema management object for MySQL
@@ -139,9 +140,21 @@ class MySQLSchemaManager extends DBSchemaManager
         return $info && strtoupper($info['Table_type']) == 'VIEW';
     }
 
+    /**
+     * Renames a table
+     *
+     * @param string $oldTableName
+     * @param string $newTableName
+     * @throws LogicException
+     * @return Query
+     */
     public function renameTable($oldTableName, $newTableName)
     {
-        $this->query("ALTER TABLE \"$oldTableName\" RENAME \"$newTableName\"");
+        if (!$this->hasTable($oldTableName)) {
+            throw new LogicException('Table '. $oldTableName . ' does not exist.');
+        }
+
+        return $this->query("ALTER TABLE \"$oldTableName\" RENAME \"$newTableName\"");
     }
 
     public function checkAndRepairTable($tableName)