fix issue #2944: asyncore doesn't handle connection refused correctly (patch...

fix issue #2944: asyncore doesn't handle connection refused correctly (patch by Alexander Shigin). Merged from 2.7 branch.

Lib/asyncore.py

@@ -435,8 +435,11 @@ class dispatcher:
             self.handle_read()
 
     def handle_connect_event(self):
-        self.connected = True
+        err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
+        if err != 0:
+            raise socket.error(err, _strerror(err))
         self.handle_connect()
+        self.connected = True
 
     def handle_write_event(self):
         if self.accepting:

Misc/ACKS

@@ -895,3 +895,4 @@ Siebren van der Zee
 Uwe Zessin
 Tarek Ziadé
 Peter Åstrand
+Alexander Shigin

Misc/NEWS

@@ -37,6 +37,8 @@ Extensions
 Library
 -------
 
+- Issue #2944: asyncore doesn't handle connection refused correctly.
+
 - Issue #4184: Private attributes on smtpd.SMTPChannel made public and
   deprecate the private attributes. Add tests for smtpd module.