[Chrome/Safari] The selection moves to the beginning of the editor after collapsing it in read only mode

[Mgsy]

Steps to reproduce

1. Create the Header 1 and the paragraph.
2. Enter read only mode.
3. Select part of the paragraph.
4. Click on the selection to collapse it.

Current result

The selection moves to the beginning of the editor (you can see that dropdown points to the Header 1).

GIF

Other information

OS: Windows 10, MacOS X
Browser: Chrome, Safari, Opera
Release: 1.0.0-Alpha1

[Reinmar]

IMO, this is "fine" or at least – not harmful :) Unless we see how this could cause any problems to anyone.

[scofalik]

This incorrect behavior is causing bugs in comments in read-only mode.

[scofalik]

Sorry, I didn't read the issue just looked at the gif :D.

The problem, in overall, is caused by the fact that in the read only mode, the selection is always converted, no matter if it ends up in the editable or outside or is removed at all (like in the case above). This is caused by an incorrect condition in selection observer.

So, when the incorrect DOM selection is mapped to view, there are no ranges in the view that can be mapped with DOM selection ranges. So an empty view selection is upcasted, which causes the bug.