Revert to system font if specified font not found on system

[droark]

In certain instances, if certain calls are given a font not found on the system, Armory attempts to revert to the system font. The call for the system font is incorrect. Patch fixes this problem.

[achow101]

This also fixes the problem I was having with the address book.

[droark]

Actually, it looks like there's a deeper problem. self.font is never getting set. It goes back to this commit from 2012. The code seems to assume that self.font is set somewhere. This isn't the case, and it looks like QDialog doesn't seem to have it. Same for ArmoryDialog. So, an error is always going to be raised. Maybe self.font was set at one point but got nuked in a bad merge or something?

[goatpig]

Actually self.font() is a method defined in QWidget, which QDialog inherits. I would say it's bad form to just reassign the name to a member variable instead.

The reason none of this crashes too hard is because self.font was indeed defined (even though it was never defined explicitly in ArmoryDialog), all due to Python's weak type semantics.

The solution is stop using self.font, use a different name and replace it whole sale across the code base.

[droark]

The solution is stop using self.font, use a different name and replace it whole sale across the code base.

I seem to be missing something, as there's only the one instance of self.font that I can see.

[droark]

Pushed a one-line change and squashed it.

[goatpig]

I seem to be missing something, as there's only the one instance of self.font that I can see.

That would explain why the issue was limited. The symptoms would have been much more visible if the mistake was wide spread.