Linux: text rendering is incorrect in QGraphicsView with an OpenGL viewport

When rendering text in a QGraphicsView with an OpenGL viewport, the letters are often off by a few pixels, sometimes too close to the letter next to it, other times too high/low. The screenshots will demonstrate this better than I can explain it.

I'm also attaching an example that demonstrates the problem. Run "gl-text" for a non-GL viewport, and "gl-text gl" for an OpenGL viewport.

This seems to have something to do with font antialiasing – disabling it makes both GL and non-GL look the same.