Donation amount is not included in the checkout email

[ipokkel]

Describe the bug When a user checks out for a level that allows donations and opts to donate during checkout, the donation amount is not included in the checkout email received by the member.

The email template targeted by the pmprodon_pmpro_email_filter function now uses Order instead of Invoice in the email body and the replace statement in this function requires updating for cases where the !!donation!! email shortcode was not present in the template body. - https://github.com/strangerstudios/pmpro-donations/blob/f279084271d77891ed9b15844c6ad20d5bb6d094/includes/checkout.php#L380

To Reproduce Steps to reproduce the behavior:

1. Check out for a membership level that allows donation as well and enter a donation value at checkout.
2. Review checkout confirmation email received by the member to observe that the donation amount was not included in the email.

Expected behavior The donation amount to be included in the checkout email

Isolating the problem (mark completed items with an [x]):

• [x] I have deactivated other plugins and confirmed this bug occurs when only Paid Memberships Pro plugin is active.
• [x] This bug happens with a default WordPress theme active, or Memberlite.
• [x] I can reproduce this bug consistently using the steps above.

WordPress Environment

PMPro 3.1.3
PMPro Donations 1.2

[MaryOJob]

Another request: #601813 Moderators Only