bpo-39259: smtp.SMTP/SMTP_SSL now reject timeout = 0 (GH-17958)

1 files changed, 8 insertions, 7 deletions

diff --git a/Lib/smtplib.py b/Lib/smtplib.py
index 6513842e..4d5cdb5 100755
--- a/Lib/smtplib.py
+++ b/Lib/smtplib.py
@@ -303,6 +303,8 @@ class SMTP:
     def _get_socket(self, host, port, timeout):
         # This makes it simpler for SMTP_SSL to use the SMTP connect code
         # and just alter the socket connection bit.
+        if timeout is not None and not timeout:
+            raise ValueError('Non-blocking socket (timeout=0) is not supported')
         if self.debuglevel > 0:
             self._print_debug('connect: to', (host, port), self.source_address)
         return socket.create_connection((host, port), timeout,
@@ -1030,13 +1032,12 @@ if _have_ssl:
                                                      keyfile=keyfile)
             self.context = context
             SMTP.__init__(self, host, port, local_hostname, timeout,
-                    source_address)
+                          source_address)
 
         def _get_socket(self, host, port, timeout):
             if self.debuglevel > 0:
                 self._print_debug('connect:', (host, port))
-            new_socket = socket.create_connection((host, port), timeout,
-                    self.source_address)
+            new_socket = super()._get_socket(host, port, timeout)
             new_socket = self.context.wrap_socket(new_socket,
                                                   server_hostname=self._host)
             return new_socket
@@ -1065,15 +1066,15 @@ class LMTP(SMTP):
     ehlo_msg = "lhlo"
 
     def __init__(self, host='', port=LMTP_PORT, local_hostname=None,
-            source_address=None):
+                 source_address=None):
         """Initialize a new instance."""
-        SMTP.__init__(self, host, port, local_hostname=local_hostname,
-                      source_address=source_address)
+        super().__init__(host, port, local_hostname=local_hostname,
+                         source_address=source_address)
 
     def connect(self, host='localhost', port=0, source_address=None):
         """Connect to the LMTP daemon, on either a Unix or a TCP socket."""
         if host[0] != '/':
-            return SMTP.connect(self, host, port, source_address=source_address)
+            return super().connect(host, port, source_address=source_address)
 
         # Handle Unix-domain sockets.
         try: