From dec12a898e2ba6b82b0f4926849d39e232944074 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Damir=20Jeli=C4=87?= <poljar@termina.org.uk>
Date: Fri, 13 Jul 2018 16:05:18 +0200
Subject: [PATCH] rooms: Return an error event instead of None upon decryption
 failure.

---
 matrix/buffer.py | 15 ++++++++++++++-
 matrix/rooms.py  | 20 +++++++++++++++++++-
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/matrix/buffer.py b/matrix/buffer.py
index 4b4270a..44245c0 100644
--- a/matrix/buffer.py
+++ b/matrix/buffer.py
@@ -46,7 +46,8 @@ from .rooms import (
     RoomRedactionEvent,
     RoomRedactedMessageEvent,
     RoomEncryptionEvent,
-    RoomPowerLevels
+    RoomPowerLevels,
+    UndecryptedEvent
 )
 
 
@@ -953,6 +954,18 @@ class RoomBuffer(object):
         elif isinstance(event, RoomPowerLevels):
             self._handle_power_level(event)
 
+        elif isinstance(event, UndecryptedEvent):
+            nick = self.find_nick(event.sender)
+            date = server_ts_to_weechat(event.timestamp)
+            data = ("Error decrypting event session "
+                    "id: {}".format(event.session_id))
+            self.weechat_buffer.message(
+                nick,
+                data,
+                date,
+                self.get_event_tags(event)
+            )
+
         else:
             W.prnt("", "Unhandled event of type {}.".format(
                 type(event).__name__))
diff --git a/matrix/rooms.py b/matrix/rooms.py
index 7bc33e0..67fc643 100644
--- a/matrix/rooms.py
+++ b/matrix/rooms.py
@@ -262,7 +262,7 @@ class RoomInfo():
         )
 
         if not plaintext:
-            return None
+            return UndecryptedEvent.from_dict(event_dict)
 
         parsed_plaintext = json.loads(plaintext, encoding="utf-8")
 
@@ -328,6 +328,24 @@ class RoomEvent(object):
         self.timestamp = timestamp
 
 
+class UndecryptedEvent(RoomEvent):
+    def __init__(self, event_id, sender, timestamp, session_id):
+        self.session_id = session_id
+        RoomEvent.__init__(self, event_id, sender, timestamp)
+
+    @classmethod
+    def from_dict(cls, event):
+        event_id = (sanitize_id(event["event_id"])
+                    if "event_id" in event else None)
+        sender = (sanitize_id(event["sender"])
+                  if "sender" in event else None)
+        timestamp = (sanitize_ts(event["origin_server_ts"])
+                     if "origin_server_ts" in event else None)
+        session_id = event["content"]["session_id"]
+
+        return cls(event_id, sender, timestamp, session_id)
+
+
 class BadEvent(RoomEvent):
     def __init__(self, event_id, sender, timestamp, source):
         RoomEvent.__init__(self, event_id, sender, timestamp)