Originally I reported bug 114618 in QtWebKit stating that monospace fonts were rendered as non-monospace, but it seems that the issue is deeper, so I was redirected here.
prints “Courier New” on my Ubuntu system, but I don’t have this font installed.
When I replace QFont::Monospace with QFont::TypeWriter, it prints just “Courier”, which also doesn’t exist.
The default fontconfig monospace font on my system is “DejaVu Sans Mono”:
Because of this bug QtWebKit renders all font-family: monospace blocks using non-monospace font, so it is quite a critical issue.