Credit memo email template file: fixing incorrect object type error

[JosephMaxwell]

Description

When creating a credit memo and checking the "Email" checkbox, you would get an error like:

Fatal error: Uncaught TypeError: Argument 1 passed to Magento\Sales\Block\Order\Email\Items\Order\DefaultOrder::getItemPrice() must be an instance of Magento\Sales\Model\Order\Item, instance of Magento\Sales\Model\Order\Creditmemo\Item given, called in /var/www/sites/magento/vendor/magento/module-sales/view/frontend/templates/email/items/creditmemo/default.phtml on line 34 and defined in /var/www/sites/magento/vendor/magento/module-sales/Block/Order/Email/Items/Order/DefaultOrder.php on line 99

Adding ->getOrderItem() sends the correct type and the error is resolved. Reference.

Manual testing scenarios

1. Create an order
2. Invoice the order
3. Create a credit memo for the order, and check "Send email".
4. You should receive an email with the credit memo instead of an error.

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[magento-engcom-team]

Hi @JosephMaxwell. Thank you for your contribution
Here is some useful tips how you can test your changes using Magento test environment.
Add the comment under your pull request to deploy test or vanilla Magento instance:

• @magento-engcom-team give me test instance - deploy test instance based on PR changes
• @magento-engcom-team give me {$VERSION} instance - deploy vanilla Magento instance

For more details, please, review the Magento Contributor Assistant documentation

[magento-engcom-team]

Hi @orlangur, thank you for the review.
ENGCOM-2148 has been created to process this Pull Request

[magento-engcom-team]

Hi @JosephMaxwell. Thank you for your contribution.
We will aim to release these changes as part of 2.2.6.
Please check the release notes for final confirmation.

Please, consider to port this solution to 2.3 release line.
You may use Porting tool to port commits automatically.