Fix for ConversionException throw when the value is empty

lib/Doctrine/DBAL/Types/ArrayType.php

@@ -38,10 +38,11 @@ class ArrayType extends Type
 
     public function convertToPHPValue($value, \Doctrine\DBAL\Platforms\AbstractPlatform $platform)
     {
-        if ($value === null) {
-            return null;
+        if (empty($value)) {
+            return array();
         }
 
+
         $value = (is_resource($value)) ? stream_get_contents($value) : $value;
         $val = unserialize($value);
         if ($val === false && $value != 'b:0;') {