Issue Summary

When updating a page that has UNPUBLISHED CHANGES, the changes will be merged, but the flag will be gone from the page.

This is reproducible on Data Center: (yes)

Steps to Reproduce

1. Create a page and publish text "A" on it.
2. Edit page again change it to "AB" and save changes (do not publish it).
3. In view mode you will see "A" with the "unpublished changes" flag on top of the page and in draft "AB".
4. Now update the same page with REST API and change it to "AC"

Expected Results

1. In view mode, you will see "AC" flag of "unpublished changes" is visible, and in edit mode, we will see "ACB". That way you can discard any changes.

Actual Results

1. In view mode, you will see "AC" flag of "unpublished changes" is not visible anymore, and in edit mode, we will see "ACB". You are unaware of "B" and you might publish it without intention.

Workaround

A potential workaround can be to discard any drafts after making change to a page with a DELETE call on this page:

<base_url>/rest/synchrony/1.0/content/<page_id>/changes/unpublished

An alternative option can be to prevent users from editing a page that has been updated by REST API.