Filed as a follow-up per @Pppery comment - https://phabricator.wikimedia.org/T370981#10083439
The issue is present on testwiki wmf.9
Steps:
- On betalabs wiki, as an admin go to Special:ManageMentors.
- Click on the Edit button to edit settings for a mentor with a custom introduction message.
- On Special:ManageMentors/edit-mentor/ [mentor userid] click the check box for Is away? status.
- Do not modify the custom introduction message of the mentor
- In the Away until field select any of the available days - click on Submit
What happened:
- the notice "Your edit was ignored because no change was made to the text." appears
- the selected date is saved
- the Away status is actually set.
What should have happened:
- no notice appears
- The form is replaced with a basic message saying "Mentorship-related options for mentor XYZ were changed."
- (We make should that message nicer. Codex success message styles?)


