Magento 2 Wishlist product add not working when user should in before login

Question

I am facing issue adding product in wishlist (magento version 2.2.3).

Here is scenario,

Step 1 :- Make sure customer not logged in.

Step 2 :- Go to product list page and click "Add to wishlist"

Step 3 :- it will redirected to login page.

Step 4 :- Now after login you can check product not added in wishlist.

Answer 1

Generate new FormKey and replace for oldRequestParams Wishlist

1. vendor\magento\module-wishlist\Helper\Data.php
   just added below code in this file...

use Magento\Framework\App\ObjectManager;
use Magento\Framework\Data\Form\FormKey;
use Magento\Framework\App\PageCache\FormKey as PageCacheFormKey;
use Magento\Framework\Session\Config\ConfigInterface;
use Magento\Framework\Stdlib\Cookie\CookieMetadataFactory;

    public function refreshFormKey()
    {
         $beforeWishlistRequest = $this->_customerSession->getBeforeWishlistRequest();


    if ($beforeWishlistRequest !== null) {

        $formKeyData = ObjectManager::getInstance()->get(FormKey::class);

        //form_key is already empty
        $formKey = $formKeyData->getFormKey();

        $sessionConfig = ObjectManager::getInstance()->get(ConfigInterface::class);
        $cookieMetadata = ObjectManager::getInstance()->get(CookieMetadataFactory::class)->createPublicCookieMetadata();
        $cookieMetadata->setDomain($sessionConfig->getCookieDomain());
        $cookieMetadata->setPath($sessionConfig->getCookiePath());
        $cookieMetadata->setDuration($sessionConfig->getCookieLifetime());

        ObjectManager::getInstance()->get(PageCacheFormKey::class)->set(
            $formKey,
            $cookieMetadata
        );

        $beforeWishlistRequest['form_key'] = $formKey;
        $this->_customerSession->setBeforeWishlistRequest($beforeWishlistRequest);
        $this->_customerSession->setBeforeRequestParams($beforeWishlistRequest);
        $this->_customerSession->setBeforeModuleName('wishlist');
        $this->_customerSession->setBeforeControllerName('index');
        $this->_customerSession->setBeforeAction('add');
    }

    return $this;
}

2. vendor\magento\module-wishlist\Observer\CustomerLogin.php

public function execute(Observer $observer)
    {
        $this->wishlistData->refreshFormKey(); // add this line only
        $this->wishlistData->calculate();
    }