Creating a draft of a child page without both a title and a page body will not display it in the page tree

Issue Summary

When creating a draft of a child page without both a title and a page body, the page tree doesn't display it even though the draft itself is created successfully.

Steps to Reproduce

1. Click the [+] button on the left of the title of the parent page in the page tree
2. After the editor appears, click the [close] button without adding the texts in the title and the body of the page

Expected Results

The draft page appears undet the parent page in the page tree like below:

▽ Parent page
    * Untitled [Draft] 

Actual Results

We can expand the tree, but the draft page does not appear under the parent page in the page tree like below:

▽ Parent page

Based on the DB, the draft itself is created successfully.

Workaround

If you realize that you inadvertently clicked the plus sign "+", when the new page opens you can go to the three dots "..." menu at the top right and select Delete unpublished page and no blank draft will be created.
If you click Close on the page the draft will be created and currently there is no known workaround for this behavior. A workaround will be added here when available.
The empty drafts are scheduled to be auto-deleted every 60 days.