Font gets smaller for each rendered page

Every time the page in the attached document is re-rendered, the font gets smaller.
First rendering:

Second rendering:

Reloading the complete document resets the font size.

This is probably caused in TTFGlyph2D.getPathForGID

The problematic text rendering uses scaling,
so the path gotten in the line

GeneralPath glyph = vectorFont.getPath(code);

is rescaled in

                if (hasScaling)
                {
                    AffineTransform atScale = AffineTransform.getScaleInstance(scale, scale);
                    glyphPath.transform(atScale);
                }

This should probably be done on a cloned path.