Bug in cmbsy*.mf source files

[barbara beeton]

On Thu, 26 Nov 2020, Enrico Gregorio wrote:

> Due to apparent typos, the METAFONT driver files for
> the cmbsy fonts provided by the AMS have wrong setting to
> the crisp parameter.

Too bad this wasn't reported 20 years ago.  AMS stated a policy
nearly that long ago that no changes were to be made to the amsfonts.
This question can be taken up through tech-support at ams.org (cc'ed);
I no longer have any influence on or input to any decision.
 						-- bb

> cmbsy10.mf
>
> crisp#:=13/36pt#; % diameter of serif corners
>
> cmbsy9.mf
>
> crisp#:=13/36pt#; % diameter of serif corners
>
> cmbsy8.mf
>
> crisp#:=12pt#; % diameter of serif corners
>
> cmbsy7.mf
>
> crisp#:=11pt#; % diameter of serif corners
>
> cmbsy6.mf
>
> crisp#:=10pt#; % diameter of serif corners
>
> cmbsy5.mf
>
> crisp#:=9pt#; % diameter of serif corners
>
> The /36 is missing from size 8 down and it has two consequences:
>
> 1. the serifs in \amalg don’t have rounded corners
> 2. the \uparrow character gets a _huge_ italic correction
>
> I checked the generated tfm file for cmbsy7 after doing the fix
> and the metrics are exactly the same, except for the italic
> correction that’s not present if 11/36pt# is used.
>
> Regenerating the Type1 fonts doesn’t seem a feasible path,
> but at least fixing the tfm files should be done.
>
> Source: https://tex.stackexchange.com/q/572446/4427
>
> The example in the question clearly shows the problem.
>
> There is a math-font-discuss mailing list, but it has
> been silent for almost eight years, so I thought it better
> to open discussion here.
>
> Ciao
> Enrico
>