Bug in undo/redo with additional new lines

That little bug exists on Windows and Linux. In version 2.0.0 and 1.2.0.

First open a file with color emojis

Then writing fast and wild some "text".

Then Undo with Ctrl+Z or over the menu

And then redo with Ctrl+Y or over the menu

After the redo you have one or more new lines. Possible with one single letter, which was before part of the longer "word"