Fixes #960 - Do a retry if exc has errno but errno is None. Python3 s…

…upport.

Since py 3, there are new "OS-exception" including RemoteDisconnected.

Sadly, these exception are oserror and are supposed to have an errno
field, but if they are raised by some parts of cpython will not have any
value for errno.

That is the case for RemoteDisconnected raised by httlib instead of
BadStatusLine previously.

S3/S3.py

@@ -1272,9 +1272,15 @@ def send_request(self, request, retries = _max_retries):
             ConnMan.put(conn)
         except (IOError, Exception) as e:
             debug("Response:\n" + pprint.pformat(response))
-            if ((hasattr(e, 'errno') and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
-               or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)) and not isinstance(e, SocketTimeoutException):
+            if ((hasattr(e, 'errno') and e.errno
+                 and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
+                or "[Errno 104]" in str(e)
+                or "[Errno 32]" in str(e)
+               ) and not isinstance(e, SocketTimeoutException):
                 raise
+            # When the connection is broken, BadStatusLine is raised with py2
+            # and RemoteDisconnected is raised by py3 with a trap:
+            # RemoteDisconnected has an errno field with a None value.
             if conn:
                 # close the connection and re-establish
                 conn.counter = ConnMan.conn_max_counter
@@ -1474,8 +1480,10 @@ def send_file(self, request, stream, labels, buffer = '', throttle = 0,
                 progress.done("failed")
             if retries:
                 known_error = False
-                if ((hasattr(e, 'errno') and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
-                   or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)) and not isinstance(e, SocketTimeoutException):
+                if ((hasattr(e, 'errno') and e.errno
+                     and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
+                    or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)
+                   ) and not isinstance(e, SocketTimeoutException):
                     # We have to detect these errors by looking at the error string
                     # Connection reset by peer and Broken pipe
                     # The server broke the connection early with an error like
@@ -1659,8 +1667,10 @@ def recv_file(self, request, stream, labels, start_position = 0, retries = _max_
         except (IOError, Exception) as e:
             if self.config.progress_meter:
                 progress.done("failed")
-            if ((hasattr(e, 'errno') and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
-               or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)) and not isinstance(e, SocketTimeoutException):
+            if ((hasattr(e, 'errno') and e.errno and
+                 e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
+                or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)
+               ) and not isinstance(e, SocketTimeoutException):
                 raise
             if conn:
                 # close the connection and re-establish
@@ -1753,8 +1763,10 @@ def recv_file(self, request, stream, labels, start_position = 0, retries = _max_
         except (IOError, Exception) as e:
             if self.config.progress_meter:
                 progress.done("failed")
-            if ((hasattr(e, 'errno') and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
-               or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)) and not isinstance(e, SocketTimeoutException):
+            if ((hasattr(e, 'errno') and e.errno
+                 and e.errno not in (errno.EPIPE, errno.ECONNRESET, errno.ETIMEDOUT))
+                or "[Errno 104]" in str(e) or "[Errno 32]" in str(e)
+               ) and not isinstance(e, SocketTimeoutException):
                 raise
             # close the connection and re-establish
             conn.counter = ConnMan.conn_max_counter