That fix wouldn't require C++ knowledge at all. It involves changing some CSS. The issue is the effect it would have on sites that expect it to be styled the way that it is.
As for the original bug, this post: https://bugzilla.mozilla.org/show_bug.cgi?id=349259#c82 seems to suggest every browser but Firefox supports changing line-height. Wouldn't Firefox be going against the expected behavior?
As for the original bug, this post: https://bugzilla.mozilla.org/show_bug.cgi?id=349259#c82 seems to suggest every browser but Firefox supports changing line-height. Wouldn't Firefox be going against the expected behavior?