I'm using C++ and Qt on Windows to create a simple application which outputs some data to the screen using a QPlainTextEdit.
The problem is that there is a small internal margin between the QPlainTextEdit's border and the text as shown here:

The text in the QPlainTextEdit has been selected to highlight the gap.
I have tried using setContentsMargins(0, 0, 0, 0) and setStyleSheet("padding:0;"), and using a QTextEdit or a QTextBrowser instead, but I still get that small margin.
Googling it only turned up this unanswered question on qtcentre.org.