Re: Help needed: nnmaildir and expire-group parameter.

[Eric Abrahamsen <eric@ericabrahamsen.net>]

Fernando de Morais <fernandodemorais.jf@gmail.com> writes:

> Hello Eric,
>
> Eric Abrahamsen <eric@ericabrahamsen.net> writes:
>
>> Look for the value of "pgname", and the 'expire-age parameter, and
>> later the 'expire-group parameter. Something in there should jump out
>> at you as "wrong".
>
> This was a very wise advice: in the end, `nnmaildir' was looking for the
> parameters of the group "inbox", not "nnmaildir:inbox".  That did the
> trick!  🎉

[...]

> Thank you very much!

Glad it wasn't any harder to resolve!

> *P.S.:* I imagine there must be a rationale behind this and it was
> defined a long time ago, but why doesn't `nnmaildir' make use of the
> `expiry-target' parameter like other backends do?

Apparently it's not using the same parameter names as everyone else,
because nnmaildir lets the user put arbitrary Lisp expressions in as
values -- it runs the values through `eval' at Gnus startup time. I
think the idea is that, because the parameter values are handled
differently, the parameter names should be different.

This doesn't particularly make sense, and the use of `eval' in regular
code is pretty heavily discouraged these days. This code seems to have
been in nnmaildir.el since The Dawn of Time, and I'm sure that at one
point someone depended heavily on being able to `eval' their parameter
values.

It would be relatively simple to fix: we could leave the existing
handling of nnmaildir's own parameters in place, but also start
retrieving the normal expiry parameters, using Gnus' regular
`gnus-group-parameter-*' functions.

Eric