StyledText formatted text isn't rendered correctly with OpenGL graphicssystem

A text area with StyledText format, a color property and text like:
"some <font color=\"#112233\">colored</font> text"
shows the problem - the final work "text" will be rendered black, instead of the color according to the color property, when using the OpenGL graphics system.

This is because the pen of the Inert paint device specified in QDeclarativeTextLayout is a default (black) pen rather than an invalid pen.