bug#75305: 31.0.50; gnus-refer-thread-use-search isn't exact enough about how the current group is searched

["Björn Bidar via Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Björn Bidar <bjorn.bidar@thaodan.de>
>> Cc: 75305@debbugs.gnu.org
>> Date: Sat, 04 Jan 2025 23:34:10 +0200
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > Thanks, but the patch seems to include unrelated changes in the code?
>> > I thought we were talking only about fixing the manual?  Or what did I
>> > miss?
>> >
>> 
>> I look at the situation further and noticed that adding the current
>> group does not work without the user writing a custom hook to add it.
>> I already wrote a hook to change gnus-refer-thread-use-search for
>> another reason, to add the current gnus-message-archive-group to 
>> gnus-refer-thread-use-search.
>> To just add the current group writing a hook would be to clumsy.
>> Using the current symbol similar as in gnus-refer-article-method is much
>> simpler, makes the setting easier to understand and customize for new 
>> users.
>> 
>> The customization changes are there to use better custom types which
>> makes it easier to customize and harder to put false values into the
>> option when using custom.
>
> Then we'll need to wait for our Gnus expert (CC'ed) to review your
> code changes.  I have some comments to the documentation part below:

OK great. 

>> * lisp/gnus/gnus-sum.el (gnus-refer-thread-use-search):
>> Make it easier to customize the variable by adding predefine choices
>> as well as descriptions to each choice. Add option to add the value
>> `current' to the list of servers and groups to add the current group.
>> E.g. to add another group and the current group.
>> * lisp/gnus/gnus-search.el (gnus-refer-thread-maybe-add-current-group,
>> gnus-search-thread): Add helper function to determine if the option
>> contains the value current. Use helper function.
>> * lisp/gnus/nnselect.el (nnselect-request-thread): Use helper function
>> to check if the value current is in gnus-refer-thread-use-search.
>> * doc/misc/gnus.texi (gnus-refer-thread-use-search):
>> Include the current value in the section. Format the section a little
>> better to have a paragraph for each possible value that the option
>> may contain. Explain the option to have a list of servers more detailed
>> , i.e. similarly to the custom description. Highlight that the current
>> group is not searched unless specified. Explain that unless the articles
>> of that thread are contained in the searched groups not adding the
>> current group might not be the desired effect.
>
> Some of the lines in the log message are too long.  Please be sure to
> wrap lines at column 64 if possible, and in any case before column 70.
>

I did so but it does make the message harder to read when long function
or variable names come into play.

The grammar errors you noticed are fixed. I also applied the suggested
changes to the docstring of the new function.