Possible problem with empty carts in Woocommerce 10.1

Hi, I’m also experiencing the same issue described by Denis.

If you still have the cart data available in the persistent cart, you can use the following snippet to restore it and move the lines back into the session cart:

add_filter('woocommerce_persistent_cart_enabled', '__return_true');

add_action('woocommerce_cart_loaded_from_session', function($cart) {
    if ( ! is_user_logged_in() || ! function_exists('WC') ) {
        return;
    }

    $user_id = get_current_user_id();

    // If the session cart already has items, do nothing.
    if ( ! $cart->is_empty() ) {
        return;
    }

    $key   = '_woocommerce_persistent_cart_' . get_current_blog_id();
    $saved = get_user_meta($user_id, $key, true);

    if ( empty($saved) || empty($saved['cart']) || ! is_array($saved['cart']) ) {
        return;
    }

    WC()->cart->empty_cart(true);

    foreach ( $saved['cart'] as $item ) {
        $product_id     = isset($item['product_id'])   ? (int) $item['product_id']   : 0;
        $variation_id   = isset($item['variation_id']) ? (int) $item['variation_id'] : 0;
        $quantity       = isset($item['quantity'])     ? (int) $item['quantity']     : 1;
        $variation      = isset($item['variation'])    ? (array) $item['variation']  : [];

        $cart_item_data = $item;
        unset($cart_item_data['product_id'], $cart_item_data['variation_id'], $cart_item_data['quantity'], $cart_item_data['variation'], $cart_item_data['data_hash']);

        if ( $product_id > 0 && $quantity > 0 ) {
            WC()->cart->add_to_cart($product_id, $quantity, $variation_id, $variation, $cart_item_data);
        }
    }

    WC()->cart->calculate_totals();
}, 20);

After adding the snippet, you need to switch to the user account that lost the cart, and the cart data should be restored.

Once you’ve recovered the data, I recommend removing this snippet and also disabling the “Switch To” plugin until a proper fix for this issue is released — or alternatively, avoid switching to another user in the meantime.

For reference, here’s a link to the latest changes related to cart handling on GitHub:

https://github.com/woocommerce/woocommerce/pull/57961

• This reply was modified 10 months ago by Joan.

I’m having the same problem here. WooCommerce now handles orders/sessions differently. A shopping cart created with the Switch User plugin is no longer permanently saved to the user (as it used to be). I think it will stay this way. WooCommerce won’t change this.

Hi @johnbillion

Steps to reproduce the issue

• In an incognito window, log in with a customer role account, browse the shop, add items to the cart, and then log out.

• Check the session_key record for the same customer (user_id) in the wp_woocommerce_sessions table. Inside the session_value, you will see the data structure containing the items you added to the cart.

• Now log in with your administrator account and use the “Switch To” function to switch into the same customer account.

• At this point, the cart appears empty. If you check the session_value again, you’ll notice that the cart item data has disappeared.

If you don’t use “Switch To” and simply log in as the customer directly, the cart data is preserved (until the session naturally expires).

I was able to solve the problem by changing the forget_woocommerce_session which is hooked to both switch_to_user and switch_back_user actions. This method originally deletes the WooCommerce session for the user being switched to, resulting in the cart being cleared.

The fix prevents WooCommerce from clearing the session when switching users. Instead of deleting the session, it transfers the WooCommerce session data from the old user to the new user during the switch. This way, the cart and other session data will persist across user switches.

	/**
	 * Preserves WooCommerce session data (cart, etc.) when switching users.
	 * Instead of deleting the session, transfer it to the new user.
	 */
	public function forget_woocommerce_session(): void {
		if ( ! function_exists( 'WC' ) || ! WC()->session ) {
			return;
		}

		$session_handler = WC()->session;
		// Get current session data
		if ( method_exists( $session_handler, 'get_session_data' ) ) {
			$session_data = $session_handler->get_session_data();
		} else {
			$session_data = [];
		}

		// Store session data in a temporary cookie for transfer
		if ( ! empty( $session_data ) ) {
			setcookie( 'user_switching_wc_session', wp_json_encode( $session_data ), time() + 60, COOKIEPATH, COOKIE_DOMAIN, is_ssl(), true );
		}

		// On switch, restore session data if available
		if ( isset( $_COOKIE['user_switching_wc_session'] ) ) {
			$restored_data = json_decode( stripslashes( $_COOKIE['user_switching_wc_session'] ), true );
			if ( is_array( $restored_data ) ) {
				foreach ( $restored_data as $key => $value ) {
					$session_handler->set( $key, $value );
				}
			}
			// Remove the cookie after restoring
			setcookie( 'user_switching_wc_session', '', time() - 3600, COOKIEPATH, COOKIE_DOMAIN, is_ssl(), true );
		}
	}