mail.py: don't try to use TLS if python doesn't have SSL support

This should hide the traceback from issue501.

mercurial/mail.py

@@ -1,68 +1,71 b''
 # mail.py - mail sending bits for mercurial
 #
 # Copyright 2006 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 from i18n import gettext as _
 from demandload import *
-demandload(globals(), "os re smtplib templater util")
+demandload(globals(), "os re smtplib templater util socket")
 
 def _smtp(ui):
     '''send mail using smtp.'''
 
     local_hostname = ui.config('smtp', 'local_hostname')
     s = smtplib.SMTP(local_hostname=local_hostname)
     mailhost = ui.config('smtp', 'host')
     if not mailhost:
         raise util.Abort(_('no [smtp]host in hgrc - cannot send mail'))
     mailport = int(ui.config('smtp', 'port', 25))
     ui.note(_('sending mail: smtp host %s, port %s\n') %
             (mailhost, mailport))
     s.connect(host=mailhost, port=mailport)
     if ui.configbool('smtp', 'tls'):
+        if not hasattr(socket, 'ssl'):
+            raise util.Abort(_("can't use TLS: Python SSL support "
+                               "not installed"))
         ui.note(_('(using tls)\n'))
         s.ehlo()
         s.starttls()
         s.ehlo()
     username = ui.config('smtp', 'username')
     password = ui.config('smtp', 'password')
     if username and password:
         ui.note(_('(authenticating to mail server as %s)\n') %
                   (username))
         s.login(username, password)
     return s
 
 class _sendmail(object):
     '''send mail using sendmail.'''
 
     def __init__(self, ui, program):
         self.ui = ui
         self.program = program
 
     def sendmail(self, sender, recipients, msg):
         cmdline = '%s -f %s %s' % (
             self.program, templater.email(sender),
             ' '.join(map(templater.email, recipients)))
         self.ui.note(_('sending mail: %s\n') % cmdline)
         fp = os.popen(cmdline, 'w')
         fp.write(msg)
         ret = fp.close()
         if ret:
             raise util.Abort('%s %s' % (
                 os.path.basename(self.program.split(None, 1)[0]),
                 util.explain_exit(ret)[0]))
 
 def connect(ui):
     '''make a mail connection. object returned has one method, sendmail.
     call as sendmail(sender, list-of-recipients, msg).'''
 
     method = ui.config('email', 'method', 'smtp')
     if method == 'smtp':
         return _smtp(ui)
 
     return _sendmail(ui, method)
 
 def sendmail(ui, sender, recipients, msg):
     return connect(ui).sendmail(sender, recipients, msg)