Attempt at making layer migrations more smooth (#158)

telethon/network/mtproto_sender.py

@@ -281,9 +281,14 @@ class MtProtoSender:
 
             # Note that this code is IMPORTANT for skipping RPC results of
             # lost requests (i.e., ones from the previous connection session)
-            if not self._process_msg(
-                    inner_msg_id, sequence, reader, updates):
+            try:
+                if not self._process_msg(
+                        inner_msg_id, sequence, reader, updates):
+                    reader.set_position(begin_position + inner_length)
+            except:
+                # If any error is raised, something went wrong; skip the packet
                 reader.set_position(begin_position + inner_length)
+                raise
 
         return True
 

telethon/telegram_bare_client.py

@@ -5,7 +5,9 @@ from os import path
 
 # Import some externalized utilities to work with the Telegram types and more
 from . import helpers as utils
-from .errors import RPCError, FloodWaitError, FileMigrateError
+from .errors import (
+    RPCError, FloodWaitError, FileMigrateError, TypeNotFoundError
+)
 from .network import authenticator, MtProtoSender, TcpTransport
 from .utils import get_appropriated_part_size
 
@@ -140,6 +142,12 @@ class TelegramBareClient:
             self.dc_options = result.dc_options
             return True
 
+        except TypeNotFoundError as e:
+            # This is fine, probably layer migration
+            self._logger.debug('Found invalid item, probably migrating', e)
+            self.disconnect()
+            self.connect(exported_auth=exported_auth)
+
         except (RPCError, ConnectionError) as error:
             # Probably errors from the previous session, ignore them
             self.disconnect()