Bug in cmbsy*.mf source files

[Enrico Gregorio]

> On 26 Nov 2020, at 15:47 , barbara beeton <bnb at tug.org> wrote:
> 
> 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);

It’s indeed very unfortunate. On the other hand,
the fact that it produces _utterly wrong_ output
should be taken into consideration.

Regenerating the fonts with the correct parameters
(that is, introducing /36 where missing) produces
exactly the same metrics (except for the wrong
italic correction) and changes very slightly the
shape of \amalg in sizes 8 and below: instead of
corners where the upper serif meet the vertical
strokes (on the outer side) there will be a curve
that will really go unnoticed if one doesn’t know
where to look.

I hope that the AMS will fix the errors: this
_might_ affect older documents, though. On the
other hand, the fact that it has gone unnoticed
for more than 20 years seems a clear sign that
nobody had noticed the bug.

Ciao
Enrico