Magento: Wrong redirect with store code in url when switching language

Change the following line in file /app/code/core/Mage/Core/Model/Url/Rewrite.php (line 252):

From

$targetUrl = $request->getBaseUrl(). '/' . $this->getRequestPath();

to

$targetUrl = $request->getBaseUrl(). '/' . $currentStore->getCode() . '/' . $this->getRequestPath();