bug#15648: 24.2.50; gnutls SSL connection to IMAP server causes emacs to crash completely

[Ted Zlatanov <tzz@lifelogs.com>]

On Wed, 23 Oct 2013 19:45:48 -0400 <emacs@kosowsky.org> wrote: 

> The irony is that the patch to fix this is about as simple and natural
> as can be... simply use one reference to the primitive
> "expand-file-name". Conversely, without such a patch there is no other
> way of making file handlers work with gnutls!

> Either the bug is in including a Cygwin path or in not using a simple
> path expansion to make the Cygwin path work. You can't include a
> Cygwin path but write code in the very same library that by design
> won't support it's own feature!

Provide a backtrace, please.  I promise you we'll consider your proposal
and all the alternatives as soon as we know what's broken.

> Just one addendum...

> If the maintainers of gnutls.el for some presumably unstated by
> compelling reason do not want to support Magic File names (aka file
> handlers),

There's no need to be snarky.  Emacs has many contributors and I
maintain gnutls.el (but welcome contributions).  I will gladly make the
change to avoid a path like "/usr/ssl/whatever" that doesn't work in
Cygwin, but I don't want to make that change in order to hide an
underlying problem.  Eli has the best background to make sense of this
problem and diagnose it.

In other words, if a magic path can break Emacs because of some library
interaction beneath the ELisp code, the fix is *probably* not at the
ELisp level because there are so many potential trigger points for the
bad behavior.

> then the library code should:

> 1. Properly disable the use of file handlers so that modified
>    primitives (like file-exist-p) fail on cygwin paths.

>    One way would be to add the following line to the let* statement in
>    gnutls-negotiate:
> 		(file-name-handler-alist nil)

> 2. DOCUMENT that gnutls doesn't support Magic File names

Thank you, we'll take that under consideration as well.

Ted