bug#69517: [PATCH] Make gnus cache work with group names having '/'

[James Thomas]

Eric Abrahamsen wrote:

> The real problem (well, one of the real problems) is that we should just
> have two central routines for reading and writing active files, so that
> there are only two places to keep in sync. Instead we have those two
> places, and then a smattering of other functions in other places that do
> something similar, and also have to be kept in sync, and I haven't done
> that. At the very least I'll need to apply your patch from 65467.
>
> The other real problem is that gnus-cache is confused about whether it
> wants to be a select method, or a modified version of article saving.
> The presence of `gnus-use-long-file-name' indicates the latter, but the
> manual's instructions about the nnml select method indicates the former.
>
> I think it should be a select method, which means that the group
> directory should be created in "News/cache" the same way it is created
> at the top level: with the "/" replaced by "_", and everything else
> using the proper "left/right" group name. Perhaps "long file names" can
> still play a role, but if so that should be via
> `nnmail-use-long-file-names', and gnus-cache in general should behave
> like a nnmail backend.

Well, I have sort of, an approach based on my earlier patch:

0001-Make-gnus-cache-work-with-group-names-having.patch
Description: Text Data

James Thomas wrote:

> +     (if (not nnmail-use-long-file-names)
> +            (nnheader-replace-chars-in-string group ?. ?/)
> +       group))

Since directory names cannot have '/' they used to be replaced by '_' in
group names before conversion. But this makes it impossible, when
generating (non-existent) active files to know whether a '_' in the
directory name was _ or / originally.

The above patch tries a possible solution inspired from [1] but would
break existing users of the cache or agent (xref-find-references
"nnmail-group-pathname") who have groups with % or / in their names.

Seems to work in my limited testing. WDYT?

Regards,
James

1:
https://stackoverflow.com/questions/9847288/is-it-possible-to-use-in-a-filename#answer-9847319