Re: Emacs choosing a font with no latin characters when passed a bogus -fn

[Jason Rumney <jasonr@gnu.org>]

Juanma Barranquero wrote:
> Until a few weeks ago, Emacs crashed when passed a non-existent
> font/fontset, like
> 
>   emacs -Q -fn "-*-nonexistent"
> 
> Now it does not crash, but I'm still getting a weird effect (as
> witnessed in the font log below, and the attached image).
> 
> AFAICS, Emacs is selecting fonts (Estrangelo Edessa, Gautami, Latha,
> Mangal, etc.) that do not have Latin characters.

In fact, it has filtered the list of fonts down to those that do not
contain support for any recognized Windows "charset", since the registry
you supplied in the xfld pattern was not mapped by
w32-charset-info-alist.  Fonts for languages with poor OS support tend
to be deliberately broken so they can be used with various kludge
solutions on older versions of Windows, so it is not surprising that
they map ASCII codepoints to one or more characters in other scripts
rather than returning the .notdef glyph or including a basic ASCII subset.

I added a script condition to the entry for iso10646-1 fonts for latin
characters in fontset.el, which should result in a random latin font
being selected instead of using these fonts.

> sort-by: -*-unspecified-unspecified-unspecified-*-428567-*-nonexistent

Where did the 428567 come from? This looks like a real bug, though it
does later get reverted to 16, so probably never noticeable.