When writing a new email i want that it is automatically saved so that when i close the app (by accident) i don't lose the data and i can continue writing.

AC

• Changes to the content should be saved
• Text changes should be cached locally, and less frequently saved to the server.
• When the draft gets saved on the server attachments and content should be stored.
• If the app was closed and the latest local draft revision was not uploaded yet the draft should be displayed as a minimized editor when the app is opened again. This draft should be uploaded to the server.

Task

• Adjust DraftService not to patch MailDetailsDraft and update it instead (if necessary)
• Extend ConfigurationDatabase to hold the latest edited draft
• Open the unfinished minimized draft on login
• Add remote draft autosave

Estimated: 24h
Time taken: 23h

Original bug report

Bug in mobile app

Describe the bug

Changing app whilst composing an email causes the current email contents to be discarded.

To Reproduce

Steps to reproduce the behavior:

1. Compose email.
2. Switch app e.g. camera to take photo attachment.
3. Switch back to Tutanota app.
4. App logs in again and email draft has been discarded.

(PS is it GitHub or iOS that is trying to add new numbered lines items every time I press return. Annoying as heck.)

Expected behavior

Tutanota should at the very least save the email to Drafts.

Smartphone (please complete the following information):

• Device: iPhone XR
• OS: iOS 15.5
• Version 3.98.12