Ihor Radchenko <yantar92@posteo.net> writes:

> What Samuel described is a sequence of M-x org-store-link followed by
> M-x org-insert-all-links. With such workflow, user can expect that the
> links are going to be stored in order. If we are instead shuffle the
> stored links, M-x org-insert-all-links may result in unexpected
> behaviour.
>
> Currently, when link to place is already stored, not error is thrown, a
> message is displayed, no link is stored, and the stored link list is not
> altered.

Attaching the patch.