From d68d70362b0bb2f99162d290c33ede6ab4c19db1 Mon Sep 17 00:00:00 2001
From: Lonami Exo <totufals@hotmail.com>
Date: Tue, 7 Jan 2020 12:13:42 +0100
Subject: [PATCH] Handle PeerIdInvalidError in delete_dialog

---
 telethon/client/dialogs.py   | 19 +++++++++++++++----
 telethon/tl/custom/dialog.py |  5 ++++-
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/telethon/client/dialogs.py b/telethon/client/dialogs.py
index 4ddc726d..4bb74c27 100644
--- a/telethon/client/dialogs.py
+++ b/telethon/client/dialogs.py
@@ -3,7 +3,7 @@ import inspect
 import itertools
 import typing
 
-from .. import helpers, utils, hints
+from .. import helpers, utils, hints, errors
 from ..requestiter import RequestIter
 from ..tl import types, functions, custom
 
@@ -435,14 +435,25 @@ class DialogMethods:
                 # Leaving a channel by username
                 await client.delete_dialog('username')
         """
+        # If we have enough information (`Dialog.delete` gives it to us),
+        # then we know we don't have to kick ourselves in deactivated chats.
+        if isinstance(entity, types.Chat):
+            deactivated = entity.deactivated
+        else:
+            deactivated = False
+
         entity = await self.get_input_entity(entity)
         ty = helpers._entity_type(entity)
         if ty == helpers._EntityType.CHANNEL:
             return await self(functions.channels.LeaveChannelRequest(entity))
 
-        if ty == helpers._EntityType.CHAT:
-            result = await self(functions.messages.DeleteChatUserRequest(
-                entity.chat_id, types.InputUserSelf()))
+        if ty == helpers._EntityType.CHAT and not deactivated:
+            try:
+                result = await self(functions.messages.DeleteChatUserRequest(
+                    entity.chat_id, types.InputUserSelf()))
+            except errors.PeerIdInvalidError:
+                # Happens if we didn't have the deactivated information
+                result = None
         else:
             result = None
 
diff --git a/telethon/tl/custom/dialog.py b/telethon/tl/custom/dialog.py
index b71b4c3f..79ef1131 100644
--- a/telethon/tl/custom/dialog.py
+++ b/telethon/tl/custom/dialog.py
@@ -112,7 +112,10 @@ class Dialog:
         Shorthand for `telethon.client.dialogs.DialogMethods.delete_dialog`
         with ``entity`` already set.
         """
-        await self._client.delete_dialog(self.input_entity, revoke=revoke)
+        # Pass the entire entity so the method can determine whether
+        # the `Chat` is deactivated (in which case we don't kick ourselves,
+        # or it would raise `PEER_ID_INVALID`).
+        await self._client.delete_dialog(self.entity, revoke=revoke)
 
     async def archive(self, folder=1):
         """