How to redirect customer to cart page after login?

Question

/app/code/core/Mage/Customer/controllers/AccountController.php

protected function _loginPostRedirect() { $session = $this->_getSession();

    if (!$session->getBeforeAuthUrl() || $session->getBeforeAuthUrl() == Mage::getBaseUrl()) {
        // Set default URL to redirect customer to
        $session->setBeforeAuthUrl($this->_getHelper('customer')->getAccountUrl());
        // Redirect customer to the last page visited after logging in
        if ($session->isLoggedIn()) {
            if (!Mage::getStoreConfigFlag(
                Mage_Customer_Helper_Data::XML_PATH_CUSTOMER_STARTUP_REDIRECT_TO_DASHBOARD
            )) {
                $referer = $this->getRequest()->getParam(Mage_Customer_Helper_Data::REFERER_QUERY_PARAM_NAME);
                if ($referer) {
                    // Rebuild referer URL to handle the case when SID was changed
                    $referer = $this->_getModel('core/url')
                        ->getRebuiltUrl( $this->_getHelper('core')->urlDecodeAndEscape($referer));
                    if ($this->_isUrlInternal($referer)) {
                        $session->setBeforeAuthUrl($referer);
                    }
                }
            } else if ($session->getAfterAuthUrl()) {
                $session->setBeforeAuthUrl($session->getAfterAuthUrl(true));
            }
        } else {
            $session->setBeforeAuthUrl( $this->_getHelper('customer')->getLoginUrl());
        }
    } else if ($session->getBeforeAuthUrl() ==  $this->_getHelper('customer')->getLogoutUrl()) {
        $session->setBeforeAuthUrl( $this->_getHelper('customer')->getDashboardUrl());
    } else {
        if (!$session->getAfterAuthUrl()) {
            $session->setAfterAuthUrl($se**strong text**ssion->getBeforeAuthUrl());
        }
        if ($session->isLoggedIn()) {
            $session->setBeforeAuthUrl($session->getAfterAuthUrl(true));
        }
    }
    $this->_redirectUrl($session->getBeforeAuthUrl(true));
}

Answer 1

PLEASE DONT CHANGE CORE FILE. YOU NEED TO OVERRIDE CONTROLLER. ITS THE BEST PRACTICE.

You need to add single line for redirect user to cart page after login:

Mage::getSingleton('customer/session')->setBeforeAuthUrl(Mage::helper('checkout/cart')->getCartUrl());

So your actual function will look like below:

protected function _loginPostRedirect()
{
    $session = $this->_getSession();

    if (!$session->getBeforeAuthUrl() || $session->getBeforeAuthUrl() == Mage::getBaseUrl()) {
        // Set default URL to redirect customer to
        $session->setBeforeAuthUrl($this->_getHelper('customer')->getAccountUrl());
        // Redirect customer to the last page visited after logging in
        if ($session->isLoggedIn()) {
            if (!Mage::getStoreConfigFlag(
                Mage_Customer_Helper_Data::XML_PATH_CUSTOMER_STARTUP_REDIRECT_TO_DASHBOARD
            )) {
                $referer = $this->getRequest()->getParam(Mage_Customer_Helper_Data::REFERER_QUERY_PARAM_NAME);
                if ($referer) {
                    // Rebuild referer URL to handle the case when SID was changed
                    $referer = $this->_getModel('core/url')
                        ->getRebuiltUrl( $this->_getHelper('core')->urlDecodeAndEscape($referer));
                    if ($this->_isUrlInternal($referer)) {
                        $session->setBeforeAuthUrl($referer);
                    }
                }
            } else if ($session->getAfterAuthUrl()) {
                $session->setBeforeAuthUrl($session->getAfterAuthUrl(true));
            }
        } else {
            $session->setBeforeAuthUrl( $this->_getHelper('customer')->getLoginUrl());
        }
    } else if ($session->getBeforeAuthUrl() ==  $this->_getHelper('customer')->getLogoutUrl()) {
        $session->setBeforeAuthUrl( $this->_getHelper('customer')->getDashboardUrl());
    } else {
        if (!$session->getAfterAuthUrl()) {
            $session->setAfterAuthUrl($session->getBeforeAuthUrl());
        }
        if ($session->isLoggedIn()) {
            $session->setBeforeAuthUrl($session->getAfterAuthUrl(true));
        }
    }
    Mage::getSingleton('customer/session')->setBeforeAuthUrl(Mage::helper('checkout/cart')->getCartUrl());
    $this->_redirectUrl($session->getBeforeAuthUrl(true));
}