3.6.6, 3.7.2, 3.8
MOODLE_36_STABLE, MOODLE_37_STABLE, MOODLE_38_STABLE
How to reproduce:
- Setup your Moodle site to use an SMTP server. You can use MailCatcher or MailHog to do so.
- As admin, go to "Site Administration > Server > HTTP" and disable "Use slash arguments".
- As admin, go to "Site administration > Messaging > Notification settings" and enable the Email processor.
- Create a course.
- Create a forum in the course and make it to have a forced subscription.
- Enrol a student and a teacher in the course.
- Login as the student, go to " Preferences > Notification preferences" and enable Email notifications for forum.
- Now login as the teacher and add a new topic in the forum. The topic must contain an embedded image. Make sure to enable "Send forum post notifications with no editing-time delay".
- Run the cron.
- Go to your mail and check that you received an email with the forum post.
- Open the mail. Check that the image isn't seen.
- Copy the image URL and open it in a new tab. You should see an error "Incorrect key".