Porting procmail to C99

Is procmail still widely used? It has its own non-autoconf build configuration system, and it's not easily fixed because it assumes that implicit function declarations are supported: sources with multiple functions are compiled (but not linked), and those functions that produce diagnostics are flagged as unsupported (or so I assume).

I'm inclined towards building procmail in C89 mode for Fedora.

Thanks,
Florian

Florian Weimer asked:

According to [1], I'd say yes: currently, ca. 6300 Debian users use it regularly.

Bruno

[1] https://qa.debian.org/popcon.php?package=procmail

Cc a maintainer.
(Stephen, this mailing list discusses modernizing C code (see https://lwn.net/Articles/913505/))

(Looking at the issue tracker, items like https://github.com/BuGlessRB/procmail/issues/1 are tracked.)

(I used Maildir and offlineimap long time ago, but nowadays it's too difficult to keep doing these stuff locally...)