bug#34949: 27.0.50; Docstring of `vc-deduce-fileset' incomplete

[Juri Linkov]

>> > It also doesn't explain the meaning of the return values
>> > FILESET-ONLY-FILES, STATE, and CHECKOUT-MODEL.
>>
>> This is hard to explain because this is internal data, I even don't know
>> where to begin.  For example, here is some code from vc-next-action
>> that uses data returned from vc-deduce-fileset:
>>
>>   (not (eq model 'implicit)) (eq state 'up-to-date)
>>
>> Do you know what 'implicit' model means here and where to find all other
>> possible model values?  Also please help to find all possible states like
>> 'up-to-date' here.  I see more states used in vc-deduce-fileset like
>> 'missing', 'ignored', 'needs-update', but where is a complete list?
>
> Would it make sense to document these values as internal for now,
> similar to what we do with the 11th return value of
> parse-partial-sexp?

Maybe.  In this case the patch could be just:

diff --git a/lisp/vc/vc.el b/lisp/vc/vc.el
index 0fd36b7c56..5da6edbd0c 100644
--- a/lisp/vc/vc.el
+++ b/lisp/vc/vc.el
@@ -1027,8 +1027,8 @@ vc-deduce-fileset
 Otherwise, throw an error.
 
 STATE-MODEL-ONLY-FILES if non-nil, means that the caller needs
-the FILESET-ONLY-FILES STATE and MODEL info.  Otherwise, that
-part may be skipped.
+the FILESET-ONLY-FILES, STATE and MODEL internal information.
+Otherwise, that part may be skipped.
 
 BEWARE: this function may change the current buffer."
   (let (backend)