Re: [RFC PATCH 1/2] fetch-prune: optimize dangling-ref reporting

Jeff King [off-list ref] writes：

...we are ultimately relying on refs_warn_dangling_symrefs(), so we'd
have to update its interface. And we also reuse the list (here, after
your patch, but already in remote.c) to pass to refs_delete_refs(). So
probably not worth it.

This patch only adds sorting code to prune_refs(), and as far as I can tell,
prune_refs() is only called once during git fetch. So I was just wondering,
would it be problematic if we moved the string_list_sort() into
refs_warn_dangling_symref() instead? And if it turns out to be safe, could
we perhaps even use strset in refs_warn_dangling_symref()?