Horizontal scroll issues in QPlainTextEdit with right-aligned text and no line wrap

If you have a QPlainTextEdit with right-aligned text (set via default text option on its document) and no line wrap, then horizontal scrolling misbehaves. All the scroll space is added to the right as a margin and the text is cropped by the left. See attached screenshots to understand it better.

I have attached a basic example code that allows to reproduce the problem.

I have reproduced the problem with the cited Qt versions but I would bet it is reproducible also with newer versions.