[Bug: 21.4.19] starttls doesn't work in smtpmail

[Stephen J. Turnbull]

Doug Orleans writes:

 > revision 1.24: it uses the macro with-no-warnings, which I believe
 > only exists in GNU Emacs, not XEmacs, and this causes the check for
 > the tls executable to silently fail (because it's inside a
 > condition-case).  When I redefined smtpmail-open-stream without the
 > with-no-warnings macro, it works fine.  I don't know if there's some
 > equivalent in XEmacs, or if there's any need for it.

Nice catch, Doug!

The idiom in XEmacs is

    (let ((display-warning-minimum-level 'emergency)) ...)

This means that warnings will still be logged to the *Warnings*
buffer.  Theoretically, you *could* get a warning of an emergency
here, but there's only one instance of a warning at that level, in
alloc.c:

  warn_when_safe
    (Qmemory, Qemergency,
     "%s\n"
     "Killing some buffers may delay running out of memory.\n"
     "However, certainly by the time you receive the 95%% warning,\n"
     "you should clean up, kill this Emacs, and start a new one.",
     str);

which is something you probably do want to know about....  Gotta love
that abuse of condition-case, too.  :-)

Simon, I think that the best thing would be to just get rid of the
with-no-warnings call (unless you know of bogus warnings that will
definitely be issued), and we probably ought to change the
condition-case to catch 'io-error, which will catch all exceptions due
to expectable process failures.