Handle initial connection if network is down correctly

telethon/network/connection/connection.py

@@ -44,9 +44,14 @@ class Connection(abc.ABC):
         Disconnects from the server.
         """
         self._disconnected.set()
-        self._send_task.cancel()
-        self._recv_task.cancel()
-        self._writer.close()
+        if self._send_task:
+            self._send_task.cancel()
+
+        if self._recv_task:
+            self._recv_task.cancel()
+
+        if self._writer:
+            self._writer.close()
 
     @property
     def disconnected(self):

telethon/network/mtprotosender.py

@@ -126,41 +126,6 @@ class MTProtoSender:
 
         await self._disconnect()
 
-    # TODO Move this out of the "Public API" section
-    async def _disconnect(self, error=None):
-        __log__.info('Disconnecting from %s...', self._connection)
-        self._user_connected = False
-        try:
-            __log__.debug('Closing current connection...')
-            self._connection.disconnect()
-        finally:
-            __log__.debug('Cancelling {} pending message(s)...'
-                          .format(len(self._pending_state)))
-            for state in self._pending_state.values():
-                if error and not state.future.done():
-                    state.future.set_exception(error)
-                else:
-                    state.future.cancel()
-
-            self._pending_state.clear()
-            self._pending_ack.clear()
-            self._last_ack = None
-
-            if self._send_loop_handle:
-                __log__.debug('Cancelling the send loop...')
-                self._send_loop_handle.cancel()
-
-            if self._recv_loop_handle:
-                __log__.debug('Cancelling the receive loop...')
-                self._recv_loop_handle.cancel()
-
-        __log__.info('Disconnection from %s complete!', self._connection)
-        if self._disconnected and not self._disconnected.done():
-            if error:
-                self._disconnected.set_exception(error)
-            else:
-                self._disconnected.set_result(None)
-
     def send(self, request, ordered=False):
         """
         This method enqueues the given request to be sent. Its send
@@ -224,12 +189,14 @@ class MTProtoSender:
         authorization key if necessary, and starting the send and
         receive loops.
         """
+        # TODO With ``asyncio.open_connection``, no timeout occurs
+        # However, these are probably desirable in some circumstances.
         __log__.info('Connecting to %s...', self._connection)
         for retry in range(1, self._retries + 1):
             try:
                 __log__.debug('Connection attempt {}...'.format(retry))
                 await self._connection.connect()
-            except (asyncio.TimeoutError, OSError) as e:
+            except OSError as e:
                 __log__.warning('Attempt {} at connecting failed: {}: {}'
                                 .format(retry, type(e).__name__, e))
             else:
@@ -274,6 +241,40 @@ class MTProtoSender:
             self._disconnected = self._loop.create_future()
         __log__.info('Connection to %s complete!', self._connection)
 
+    async def _disconnect(self, error=None):
+        __log__.info('Disconnecting from %s...', self._connection)
+        self._user_connected = False
+        try:
+            __log__.debug('Closing current connection...')
+            self._connection.disconnect()
+        finally:
+            __log__.debug('Cancelling {} pending message(s)...'
+                          .format(len(self._pending_state)))
+            for state in self._pending_state.values():
+                if error and not state.future.done():
+                    state.future.set_exception(error)
+                else:
+                    state.future.cancel()
+
+            self._pending_state.clear()
+            self._pending_ack.clear()
+            self._last_ack = None
+
+            if self._send_loop_handle:
+                __log__.debug('Cancelling the send loop...')
+                self._send_loop_handle.cancel()
+
+            if self._recv_loop_handle:
+                __log__.debug('Cancelling the receive loop...')
+                self._recv_loop_handle.cancel()
+
+        __log__.info('Disconnection from %s complete!', self._connection)
+        if self._disconnected and not self._disconnected.done():
+            if error:
+                self._disconnected.set_exception(error)
+            else:
+                self._disconnected.set_result(None)
+
     async def _reconnect(self):
         """
         Cleanly disconnects and then reconnects.
@@ -340,7 +341,7 @@ class MTProtoSender:
 
             # TODO Debug logs to notify which messages are being sent
             # TODO Try sending them while no future was cancelled?
-            # TODO Handle timeout, cancelled, arbitrary errors
+            # TODO Handle cancelled?, arbitrary errors
             await self._connection.send(state_list)
             for state in state_list:
                 if not isinstance(state, list):
@@ -411,10 +412,6 @@ class MTProtoSender:
             if not state.future.cancelled():
                 state.future.set_exception(error)
         else:
-            # TODO Would be nice to avoid accessing a per-obj read_result
-            # Instead have a variable that indicated how the result should
-            # be read (an enum) and dispatch to read the result, mostly
-            # always it's just a normal TLObject.
             with BinaryReader(rpc_result.body) as reader:
                 result = state.request.read_result(reader)