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

[Stefan Monnier <monnier@iro.umontreal.ca>]

> I'm surprised that such a function doesn't (yet) exist in Emacs...

It's largely a reflection about the fact that such a need is not very
frequent, and that most people who bump into it prefer hacking their way
around the problem rather than fix it for good.

> 1. Adding expand-file-name will work for any file name that
>    cygwin-mount is designed to address (this is by definition)

"By definition" of cygwin-mount, not of expand-file-name, sadly.

> 2. Similarly, adding expand-file-name will likely work for any other
>    Magic File handler that works similar to cygwin-mount in terms of

I don't know of any other that works this way.

> Basically, this version does 2 things:
> 1. Pre-expands the file name *if* there is a Magic File handler for that
>    file path (this will do nothing if there is no handler for that path)
> 2. Tests file-exists-p with all Magic File handlers shut off which
>    tests to make sure that the OS primitives will work on the actual
>    file path that will be passed

It's a cleaner workaround, but I'd rather we come up with an actual fix.
Do you think you can try to make a patch that adds (in files.el) a new
function meant to turn an Elisp file name into an OS file name or return
nil if the file can't be accessed by OS primitives?  This function would
just delegate its work to the file-name-handler if any, and otherwise
just return its argument unchanged.


        Stefan