bug#16253: 24.3.50; Irrelevant warnings from gnutls

[Ted Zlatanov <tzz@lifelogs.com>]

On Mon, 20 Jan 2014 12:19:52 -0800 Lars Ingebrigtsen <larsi@gnus.org> wrote: 

LI> Ted Zlatanov <tzz@lifelogs.com> writes:
>> The URL library can't trap these.  GnuTLS considers them highest
>> priority, so blocking them out would block most useful log information.

LI> Useful to whom?  It's probably useful when developing applications that
LI> talk TLS, but it's not useful to the user who's just trying to read a
LI> web page.

LI> If you're reading a page, and you're loading a picture that fails, Emacs
LI> should display a "failed download" image, not spew TLS-level errors to
LI> the user.  The user isn't interested.

LI> So I think that, basically, no TLS errors should be displayed to the
LI> user.  At least I haven't seen one yet that's been useful to me as a
LI> user.

OK.  I will log them to a special " *TLS errors*" buffer.  That's a good
balance.

Doing that from C is not obvious, compared to the standard `message'
function.  Any hints?  Should I just call `Fget-buffer-create' and
call functions to append to the returned buffer Lisp_Object, or is there
a magical equivalent?

Also, I think we should add that buffer, plus the version of GnuTLS and
the priority string, to bug reports.  WDYT?

Thanks
Ted