Add a workaround for MUC reflections

with an option for broken muc implementions which change message ids on
the fly.

README.rst

@@ -53,6 +53,5 @@ information about autoloading plugins.
 TODO
 ----
 
-- MUC support. Needs support for handling MUC reflections in poezio first.
 - aesgcm
 - UI, various commands and indicators that messages are encrypted or not.

poezio_omemo/__init__.py

@@ -44,6 +44,8 @@ class Plugin(E2EEPlugin):
         (slixmpp_omemo.OMEMO_BASE_NS, 'encrypted'),
     ]
 
+    self_muc_messages: Dict[str, str] = {}
+
     # TODO: Look into blind trust stuff.
     # https://gist.github.com/mar-v-in/b683220a55bc65dcdafc809be9c5d0e4
     trust_states = {
@@ -57,6 +59,12 @@ class Plugin(E2EEPlugin):
     }
     supported_tab_types = (DynamicConversationTab, StaticConversationTab, MucTab)
 
+    default_config = {
+        # Some MUC services may not reflect the message ids properly, in which
+        # case it is better to set this option to false.
+        'enable_muc': True,
+    }
+
     def init(self) -> None:
         super().init()
 
@@ -102,7 +110,6 @@ class Plugin(E2EEPlugin):
         ]
 
     def decrypt(self, message: Message, jid: Optional[JID], tab: ChatTab) -> None:
-
         if jid is None:
             self.display_error('Unable to decrypt the message.')
             return None
@@ -120,9 +127,14 @@ class Plugin(E2EEPlugin):
         except (MissingOwnKey,):
             # The message is missing our own key, it was not encrypted for
             # us, and we can't decrypt it.
-            self.display_error(
+            if (message['type'] == 'groupchat' and
-                'I can\'t decrypt this message as it is not encrypted for me.'
+                    message['id'] in self.self_muc_messages):
-            )
+                body = self.self_muc_messages.pop(message['id'])
+            else:
+                self.display_error(
+                    'I can\'t decrypt this message as it '
+                    'is not encrypted for me.'
+                )
         except (NoAvailableSession,) as exn:
             # We received a message from that contained a session that we
             # don't know about (deleted session storage, etc.). We can't
@@ -152,6 +164,8 @@ class Plugin(E2EEPlugin):
             return None
 
         body = message['body']
+        if self.config.get('enable_muc', True) and message['type'] == 'groupchat':
+            self.self_muc_messages[message['id']] = body
         expect_problems = {}  # type: Dict[JID, List[int]]
 
         while True: