fix(breakout-rooms): Fix polls usage.

doc/debian/jitsi-meet-prosody/prosody.cfg.lua-jvb.example

@@ -124,4 +124,5 @@ Component "lobby.jitmeet.example.com" "muc"
     muc_room_default_public_jids = true
     modules_enabled = {
         "muc_rate_limit";
+        "polls";
     }

react/features/polls/actionTypes.js

@@ -10,6 +10,15 @@
  */
 export const CHANGE_VOTE = 'CHANGE_VOTE';
 
+/**
+ * The type of the action which signals that we need to clear all polls from the state.
+ * For example we are moving to another conference.
+ *
+ * {
+ *     type: CLEAR_POLLS
+ * }
+ */
+export const CLEAR_POLLS = 'CLEAR_POLLS';
 
 /**
  * The type of the action which signals that a new Poll was received.

react/features/polls/actions.js

@@ -2,6 +2,7 @@
 
 import {
     CHANGE_VOTE,
+    CLEAR_POLLS,
     RESET_NB_UNREAD_POLLS,
     RECEIVE_ANSWER,
     RECEIVE_POLL,
@@ -10,6 +11,17 @@ import {
 } from './actionTypes';
 import type { Answer, Poll } from './types';
 
+/**
+ * Action to signal that existing polls needs to be cleared from state.
+ *
+ * @returns {{
+ *     type: CLEAR_POLLS
+ * }}
+ */
+export const clearPolls = () => {
+    return { type: CLEAR_POLLS };
+};
+
 /**
  * Action to signal that a poll's vote will be changed.
  *

react/features/polls/reducer.js

@@ -4,6 +4,7 @@ import { ReducerRegistry } from '../base/redux';
 
 import {
     CHANGE_VOTE,
+    CLEAR_POLLS,
     RECEIVE_POLL,
     RECEIVE_ANSWER,
     REGISTER_VOTE,
@@ -38,6 +39,13 @@ ReducerRegistry.register('features/polls', (state = INITIAL_STATE, action) => {
         };
     }
 
+    case CLEAR_POLLS: {
+        return {
+            ...state,
+            ...INITIAL_STATE
+        };
+    }
+
     // Reducer triggered when a poll is received
     case RECEIVE_POLL: {
         const newState = {

react/features/polls/subscriber.js

@@ -9,7 +9,7 @@ import {
     showNotification
 } from '../notifications';
 
-import { receiveAnswer, receivePoll } from './actions';
+import { clearPolls, receiveAnswer, receivePoll } from './actions';
 import { COMMAND_NEW_POLL, COMMAND_ANSWER_POLL, COMMAND_OLD_POLLS } from './constants';
 import type { Answer, Poll } from './types';
 
@@ -122,6 +122,9 @@ StateListenerRegistry.register(
 
             conference.on(JitsiConferenceEvents.ENDPOINT_MESSAGE_RECEIVED, receiveMessage);
             conference.on(JitsiConferenceEvents.NON_PARTICIPANT_MESSAGE_RECEIVED, receiveMessage);
+
+            // clean old polls
+            store.dispatch(clearPolls());
         }
     }
 );