What to do about libidn?

[Joseph Myers]

On Tue, 8 Nov 2016, Florian Weimer wrote:

> This has several problems:

8. Updating libidn would be problematic for license reasons (it's 
non-FSF-assigned and upsteam is now LGPLv3).

> Should we remove our internal copy and try to dlopen libidn2?  Maybe falling
> back to libidn if libdn2 is unavailable?  Bundle libidn2?  Write our own
> implementation?

Given that glibc's libidn add-on is not itself a public ABI or API, 
dlopening an external library would seem a reasonable way of implementing 
that getaddrinfo functionality.

Suppose we remove libidn (with or without keeping the libidn functionality 
through dlopen of another library).  Then we have no in-tree uses of the 
add-ons mechanism.  Do we have any use for keeping that mechanism for 
out-of-tree add-ons, or should it be removed?

-- 
Joseph S. Myers
joseph@codesourcery.com