Re: A few Windows build fixes

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

>> >> We'd want it to have zero impact to the users who don't use cygwin
>> >> (and may not even have it installed), of course.
>> > They will never see such file names.
>> That can be argued (all file names starting with "/" are potential
>> Cygwin names).
> I was talking about /cygdrive/x/ file names that should be translated
> to x:/ and vice versa.  This must be on the C level, AFAIU.

For me, the convincing argument to add a "convert-external-file-name"
function to use on command-line args and such was specifically to be
able to handle *all* forms of Cygwin file names, including the ones that
are ambiguous (/home/foo was one motivating example, if I remember).
This was brought up in a feature-request for emacsclient arguments.

> The "mounted" file names, if we want or need to support them, will
> have to be looked up in the mount list taken from "mount -m".

FWIW, in that example, the mount point was "/some/where is mounted on /"
(and as it turns out the "mounted on /" is a case not handled by
cygwin-mount.el).  So /home/foo really meant /some/where/home/foo, but
to figure that out, we'd first have to decide whether to interpret
/home/foo as a Cygwin name or as a native name.

> I don't see how the fact that Cygwin is or isn't installed is related
> to implementing the translation, except that "mount -m" will fail if
[...]
> Loading the Cygwin DLL into a native w32 process is impossible, so
> that's not an option.

I see, so indeed, Cygwin's availability is irrelevant since we won't use
the Cygwin DLL anyway.

>> I thought we still had problems delivering signals to them.
> You are right, we don't support sending Posix signals to Cygwin
> programs.  But where is that a real problem?  Emacs does know how to
> interrupt a subprocess, and the way it does that should work with
> Cygwin programs as well, albeit with less flexibility.  After all,
> Cygwin programs are just specialized Windows applications.

It is a cause of problems for the SSL/TLS support (when we use
gnutls-cli rather than the gnutls DLL), for example.


        Stefan