Set platform instance if passed in connection params and remove it from there.

lib/Doctrine/DBAL/Connection.php

@@ -211,6 +211,15 @@ class Connection implements DriverConnection
             unset($this->_params['pdo']);
         }
 
+        if (isset($params["platform"])) {
+            if ( ! $params['platform'] instanceof Platforms\AbstractPlatform) {
+                throw DBALException::invalidPlatformSpecified();
+            }
+
+            $this->platform = $params["platform"];
+            unset($this->_params["platform"]);
+        }
+
         // Create default config and event manager if none given
         if ( ! $config) {
             $config = new Configuration();
@@ -384,7 +393,6 @@ class Connection implements DriverConnection
      */
     private function detectDatabasePlatform()
     {
-        if ( ! isset($this->_params['platform'])) {
         $version = $this->getDatabasePlatformVersion();
 
         if (null !== $version) {
@@ -392,11 +400,6 @@ class Connection implements DriverConnection
         } else {
             $this->platform = $this->_driver->getDatabasePlatform();
         }
-        } elseif ($this->_params['platform'] instanceof Platforms\AbstractPlatform) {
-            $this->platform = $this->_params['platform'];
-        } else {
-            throw DBALException::invalidPlatformSpecified();
-        }
 
         $this->platform->setEventManager($this->_eventManager);
     }