From 47d9de98ed6b62d8017ac6ec3a94c1bd30883ffa Mon Sep 17 00:00:00 2001
From: Lonami Exo <totufals@hotmail.com>
Date: Wed, 13 Feb 2019 08:51:26 +0100
Subject: [PATCH] Raise ImportError and not ValueError when sqlite3 is missing

Excepting ValueError when creating the SQLiteSession could hide
other errors (e.g. using a newer session file on an older version
of the library). Instead, the original error is raised, as if
sqlite3 was being imported within its __init__ method.
---
 telethon/client/telegrambaseclient.py | 2 +-
 telethon/sessions/sqlite.py           | 6 ++++--
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/telethon/client/telegrambaseclient.py b/telethon/client/telegrambaseclient.py
index 02cb05e9..56e1926f 100644
--- a/telethon/client/telegrambaseclient.py
+++ b/telethon/client/telegrambaseclient.py
@@ -202,7 +202,7 @@ class TelegramBaseClient(abc.ABC):
         if isinstance(session, str) or session is None:
             try:
                 session = SQLiteSession(session)
-            except ValueError:
+            except ImportError:
                 import warnings
                 warnings.warn(
                     'The sqlite3 module is not available under this '
diff --git a/telethon/sessions/sqlite.py b/telethon/sessions/sqlite.py
index ebb773e3..f01843dc 100644
--- a/telethon/sessions/sqlite.py
+++ b/telethon/sessions/sqlite.py
@@ -14,8 +14,10 @@ from ..tl.types import (
 
 try:
     import sqlite3
-except ImportError:
+    sqlite3_err = None
+except ImportError as e:
     sqlite3 = None
+    sqlite3_err = type(e)
 
 EXTENSION = '.session'
 CURRENT_VERSION = 5  # database version
@@ -32,7 +34,7 @@ class SQLiteSession(MemorySession):
 
     def __init__(self, session_id=None):
         if sqlite3 is None:
-            raise ValueError('sqlite3 is not installed')
+            raise sqlite3_err
 
         super().__init__()
         self.filename = ':memory:'