Bug in cmbsy*.mf source files

[Enrico Gregorio]

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

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