From 1f860eb1bbbc7c7a14906db73c71061ad8c3b73e Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Thu, 1 Oct 2020 11:45:34 +0300
Subject: [PATCH] Change raise_last to a client-wide switch

---
 telethon/client/telegrambaseclient.py |  9 +++++++++
 telethon/client/users.py              | 10 +++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/telethon/client/telegrambaseclient.py b/telethon/client/telegrambaseclient.py
index ce80211b..444a4181 100644
--- a/telethon/client/telegrambaseclient.py
+++ b/telethon/client/telegrambaseclient.py
@@ -160,6 +160,12 @@ class TelegramBaseClient(abc.ABC):
             was for 21s, it would ``raise FloodWaitError`` instead. Values
             larger than a day (like ``float('inf')``) will be changed to a day.
 
+        raise_last_call_error (`bool`, optional):
+            When API calls fail in a way that causes Telethon to retry
+            automatically, should the RPC error of the last attempt be raised
+            instead of a generic ValueError. This is mostly useful for
+            detecting when Telegram has internal issues.
+
         device_model (`str`, optional):
             "Device model" to be sent when creating the initial connection.
             Defaults to 'PC (n)bit' derived from ``platform.uname().machine``, or its direct value if unknown.
@@ -216,6 +222,7 @@ class TelegramBaseClient(abc.ABC):
             auto_reconnect: bool = True,
             sequential_updates: bool = False,
             flood_sleep_threshold: int = 60,
+            raise_last_call_error: bool = False,
             device_model: str = None,
             system_version: str = None,
             app_version: str = None,
@@ -306,6 +313,8 @@ class TelegramBaseClient(abc.ABC):
                 )
             )
 
+        self._raise_last_call_error = raise_last_call_error
+
         self._request_retries = request_retries
         self._connection_retries = connection_retries
         self._retry_delay = retry_delay or 0
diff --git a/telethon/client/users.py b/telethon/client/users.py
index 0d9b357a..345fb339 100644
--- a/telethon/client/users.py
+++ b/telethon/client/users.py
@@ -26,10 +26,10 @@ def _fmt_flood(delay, request, *, early=False, td=datetime.timedelta):
 
 
 class UserMethods:
-    async def __call__(self: 'TelegramClient', request, ordered=False, raise_last=False):
-        return await self._call(self._sender, request, ordered=ordered, raise_last=raise_last)
+    async def __call__(self: 'TelegramClient', request, ordered=False):
+        return await self._call(self._sender, request, ordered=ordered)
 
-    async def _call(self: 'TelegramClient', sender, request, ordered=False, raise_last=False):
+    async def _call(self: 'TelegramClient', sender, request, ordered=False):
         requests = (request if utils.is_list_like(request) else (request,))
         for r in requests:
             if not isinstance(r, TLRequest):
@@ -52,7 +52,7 @@ class UserMethods:
         request_index = 0
         last_error = None
         self._last_request = time.time()
-        
+
         for attempt in retry_range(self._request_retries):
             try:
                 future = sender.send(request, ordered=ordered)
@@ -118,7 +118,7 @@ class UserMethods:
                     raise
                 await self._switch_dc(e.new_dc)
 
-        if raise_last and last_error is not None:
+        if self._raise_last_call_error and last_error is not None:
             raise last_error
         raise ValueError('Request was unsuccessful {} time(s)'
                          .format(attempt))