Re: Updated GnuTLS from MSYS2 and Emacs's `dynamic-library-alist'

[Andy Moreton <andrewjmoreton@gmail.com>]

On Thu 30 Apr 2015, Alexander Shukaev wrote:

> Hello Devs,
>
> Recently, the GnuTLS from MSYS2 has been updated to the 3.4 version. As a
> result, the name of corresponding DLL has changed. Currently to
> "libgnutls-30.dll", but maybe it's a mistake and we will change it to
> "libgnutls-34.dll". In any case, currently Emacs has the following GnuTLS
> setting in the `dynamic-library-alist':
>
>     (gnutls "libgnutls-28.dll" "libgnutls-26.dll")

The number in the DLL name is the ABI version of the library interface,
which does change with every release. 

gnutls-30.dll is already supported in emacs master - see term/w32-win.el
where it sets dynamic-library-alist. The interface for gnutls-30.dll has
come incompatible changes from previous versions, so which DLLs are
supported depend on which gnutls version was used to build emacs.


> What would be your recommendation to properly add new versions of GnuTLS?
> Upstream or should I create a custom MSYS2 patch? Note that aside from Git
> version, we also support release versions such as 24.5, and it seems like a
> patch is inevitable in this case right?

For emacs 25 (git master) this already works.

For emacs 24, the gnutls changes (commit dc79845a "Support GnuTLS v3.4
and later on MS-Windows") need to be backported to the emacs24 branch,
so somebody needs to do that work.

    AndyM