Re: Thunderbird, ligatures, and "fixed-width" fonts

On 1/14/24 10:36, George Mitchell wrote:
> I read mail with Thunderbird and for my fixed-width font I used Noto
> Mono.  Since by design Noto has glyphs for all Unicode characters,
> that means it contains glyphs for ligatures (those character pairs
> beloved of typographers that condense certain combinations such as
> "fi" and "ffl" into single glyphs.  At some level between the text of
> the mail I'm reading or composing, which does not use those Unicode
> ligature code points, and the pixels that appear on my screen, my
> fixed-width text is no longer rendered with fixed width glyphs.
> [...]

With help from Bertrand Petit and Stephen Hurd, I found out that this
is a feature of the font system itself, or at least fontconfig.  The
fix is to create a new file, ~/.config/fontconfig/fonts.conf, and put
the contents of:
https://bugs.freebsd.org/bugzilla/attachment.cgi?id=247050
in it.

To my mind, the idea that the font system itself would do this sort of
manipulation to the text it's rendering is a severe violation of the
Principle of Least Astonishment.  Who thought this would be a good idea?
-- George