Deus Max <deusmax@gmx.com> writes:

> Reading the manual
> (https://www.gnu.org/software/emacs/manual/html_node/elisp/Hash-Access.html#Hash-Access)
> on remhash, it says: "In Emacs Lisp, remhash always returns nil.", so I
> modified the calling function gnus-dup-unsuppress-article in gnus-dup.el, as follows:
>
> 157c157,159
> <       (remhash id gnus-dup-hashtb))))
> ---
>>       (if (hash-table-p gnus-dup-hashtb)
>>           (remhash id gnus-dup-hashtb)
>>         nil))))
>
> This patch seems to have fixed the problem and now
> gnus-summary-move-article works fine. !
> the value of gnus-dup-hashtb was nil, for the problem runs.

The return value of gnus-dup-unsuppress-article doesn't matter, only
that remhash not be passed a nil gnus-dup-hashtb.

In other words, gnus-dup-unsuppress-article should either not be called
or should handle the case when it is called before gnus-dup-open has
initialised gnus-dup-hashtb.

I attach a patch which follows the apparent gnus-sum.el convention of
guarding calls to gnus-dup.el functions based on the value of
gnus-suppress-duplicates.

This fixes the immediate issue at hand, but I think there may still be a
problem when gnus-suppress-duplicates is enabled at a later time.  I
think that deserves a separate bug report, though.

Thanks,

-- 
Basil