Don't save mail as draft when closing unless changes have been made

[Pa7Hub]

With the new minimization of mails we also save a draft upon closing the editor. This helps when finishing a mail and saving changes that have been made, however can get annoying when every close triggers a draft save.

It would be better and more convenient that we only save a draft if changes have been made to the mail.

AC:

• If I do not change the body of the mail, pressing close should not trigger a draft save. Only when something has been changed (such as recipients, title, etc.) should we trigger a draft save.

Discussed with @johnbotris @Pa7Hub , should be discussed again with @bedhub

Test notes

• Create a new email without writing anything in it.
• Close the email. It should not save a draft.
• Create another new email, but this time change something in it (upload an attachment, etc.)
• Close the email. It should save a draft.
• the above works with forwarding and replies
• when a draft is saved with a recipient from the contacts, then opened (without changing it) and the contact gets edited (loses the mail address), the draft is saved on closing it.
• notification mails for calendar event participants still work

[vachan-maker]

Yep, this improvement would be nice.

[charlag]

We decided before with @bedhub that it will be more consistent to always save as there are some cases where you might expect it e.g. when it is a reply and you want to come back to it

[LewisMichaelHarold]

I have an android mobile device and my drafts are not saved when closing the app?

[Jlll1]

Maybe in case of empty messages we could just prompt the user if he wants to save it as draft? My Messaging app does that for empty messages.