Related: fdo#58277 only DelRight after a successful GotoField

otherwise you're just deleting a char right after whereever
the cursor used to be.

It can be possible to not GotoField if the field in question
is in a redline-deleted portion and show changes is not on. i.e.
its actually already deleted

Change-Id: Ic4833d82c5c33e556f3e159e9732a6db071f5622