bug#2667: Still seeing inconsistent fonts

[Chong Yidong]

> I also noticed recently that my fonts are inconsistent: when writing
> math symbols (mostly greek letters), I notice that they do not use my
> misc-fixed font but "DejaVu Sans" instead.
>
>   > xrdb -remove; rm ~/.Xdefaults
>   > emacs -Q ~/re/papers/comp-deptypes/main.tex
>   M-: (setq font-log nil) RET
>   M-: (set-face-font 'default
>   > "-misc-fixed-medium-r-semicondensed--13-*-*-*-*-*-*-*")
>
> And now all my latin text uses my beloved misc-fixed
> but all the math symbols use "DejaVu Sans"

I can't reproduce this.  Could you provide a self-contained testcase?