Error moving FCEs in DRAFT workspace

[supercaccia]

Reproduced in TYPO3 v8, v10 with flux master and flux development

Steps to reproduce:

1. In workspace create a page with an FCE (for example a grid) that contains elements and publish the page

2. For example move the FCE to another column of the page layout backend

3. Now moves the FCE back to the same column it was in before the move

At this point, the following errors appear:

1: Record cannot be versioned because it is a placeholder for a moving operation
1: Could not be edited in offline workspace in the branch where found (failure state: 'Online record was not in a workspace!'). Auto-creation of version failed!

Note: if you reload the page, the moving operation seems to have been successful anyway even if the error appeared!

I found the point in the code that causes the problem, if you comment on this part the problem is solved: