Supports the purchaser entering the recipient address at checkout for a woocommerce-subscriptions-gifting (https://github.com/Prospress/woocommerce-subscriptions-gifting) gift.

reinstate-shipto-address.php

<?php

add_action( 'woocommerce_checkout_subscription_created', 'maybe_reinstate_gifting_address', 99, 3 );

/**
	 * Ugly hack to reinstate the ship to address, if it's been removed by the gifting plugin
	 * Don't remove if it's an existing user though
	 * @param  [type] $subscription   [description]
	 * @param  [type] $order          [description]
	 * @param  [type] $recurring_cart [description]
	 * @return [type]                 [description]
	 */
	function maybe_reinstate_gifting_address( $subscription, $order, $recurring_cart ) {

		 // only process immediate gift subscriptions
		 $cart_item = reset( $recurring_cart->cart_contents );

		 if ( ! empty( $cart_item['wcsg_gift_recipients_email'] ) ) {

			$recipient_user_id = email_exists( $cart_item['wcsg_gift_recipients_email'] );

			if ( 'true' === get_user_meta( $recipient_user_id, 'wcsg_update_account', true ) ) {

				$address = array(
				 'first_name' => $order->get_shipping_first_name(),
				 'last_name'  => $order->get_shipping_last_name(),
				 'country'    => $order->get_shipping_country(),
				 'company'    => $order->get_shipping_company(),
				 'address_1'  => $order->get_shipping_address_1(),
				 'address_2'  => $order->get_shipping_address_2(),
				 'city'       => $order->get_shipping_city(),
				 'state'      => $order->get_shipping_state(),
				 'postcode'   => $order->get_shipping_postcode(),
				);

				$subscription->set_address( $address, 'shipping' );

			}
		}
	}