Patch by milokment to fix charset configuration and allow to change oci session mode.

lib/Doctrine/DBAL/Driver/OCI8/Driver.php

@@ -36,7 +36,9 @@ class Driver implements \Doctrine\DBAL\Driver
         return new OCI8Connection(
             $username,
             $password,
-            $this->_constructDsn($params)
+            $this->_constructDsn($params),
+            isset($params['charset']) ? $params['charset'] : null,
+            isset($params['sessionMode']) ? $params['sessionMode'] : OCI_DEFAULT
         );
     }
 
@@ -67,10 +69,6 @@ class Driver implements \Doctrine\DBAL\Driver
             $dsn .= $params['dbname'];
         }
 
-        if (isset($params['charset'])) {
-            $dsn .= ';charset=' . $params['charset'];
-        }
-
         return $dsn;
     }
 

lib/Doctrine/DBAL/Driver/OCI8/OCI8Connection.php

@@ -37,13 +37,13 @@ class OCI8Connection implements \Doctrine\DBAL\Driver\Connection
      * @param string $password
      * @param string $db
      */
-    public function __construct($username, $password, $db)
+    public function __construct($username, $password, $db, $charset = null, $sessionMode = OCI_DEFAULT)
     {
         if (!defined('OCI_NO_AUTO_COMMIT')) {
             define('OCI_NO_AUTO_COMMIT', 0);
         }
 
-        $this->_dbh = @oci_connect($username, $password, $db);
+        $this->_dbh = @oci_connect($username, $password, $db, $charset, $sessionMode);
         if (!$this->_dbh) {
             throw OCI8Exception::fromErrorInfo(oci_error());
         }