fix(prejoin): Fix join without audio

react/features/base/config/actionTypes.js

  * and the passed object.
  *
  * {
- *     type: _UPDATE_CONFIG,
+ *     type: UPDATE_CONFIG,
  *     config: Object
  * }
  */
-export const _UPDATE_CONFIG = '_UPDATE_CONFIG';
+export const UPDATE_CONFIG = 'UPDATE_CONFIG';

react/features/base/config/actions.js

 import { addKnownDomains } from '../known-domains';
 import { parseURIString } from '../util';
 
-import { CONFIG_WILL_LOAD, LOAD_CONFIG_ERROR, SET_CONFIG } from './actionTypes';
+import { CONFIG_WILL_LOAD, LOAD_CONFIG_ERROR, SET_CONFIG, UPDATE_CONFIG } from './actionTypes';
 import { _CONFIG_STORE_PREFIX } from './constants';
 import { setConfigFromURLParams } from './functions';
 
+
+/**
+ * Updates the config with new options.
+ *
+ * @param {Object} config - The new options (to add).
+ * @returns {Function}
+ */
+export function updateConfig(config: Object) {
+    return {
+        type: UPDATE_CONFIG,
+        config
+    };
+}
+
 /**
  * Signals that the configuration (commonly known in Jitsi Meet as config.js)
  * for a specific locationURL will be loaded now.

react/features/base/config/middleware.js

 import { MiddlewareRegistry } from '../redux';
 import { parseURIString } from '../util';
 
-import { _UPDATE_CONFIG, SET_CONFIG } from './actionTypes';
+import { SET_CONFIG } from './actionTypes';
+import { updateConfig } from './actions';
 import { _CONFIG_STORE_PREFIX } from './constants';
 
 /**
         config.resolution = resolutionFlag;
     }
 
-    dispatch({
-        type: _UPDATE_CONFIG,
-        config
-    });
+    dispatch(updateConfig(config));
 
     // FIXME On Web we rely on the global 'config' variable which gets altered
     // multiple times, before it makes it to the reducer. At some point it may

react/features/base/config/reducer.js

 
 import { equals, ReducerRegistry, set } from '../redux';
 
-import { _UPDATE_CONFIG, CONFIG_WILL_LOAD, LOAD_CONFIG_ERROR, SET_CONFIG } from './actionTypes';
+import { UPDATE_CONFIG, CONFIG_WILL_LOAD, LOAD_CONFIG_ERROR, SET_CONFIG } from './actionTypes';
 import { _cleanupConfig } from './functions';
 
 /**
 
 ReducerRegistry.register('features/base/config', (state = _getInitialState(), action) => {
     switch (action.type) {
-    case _UPDATE_CONFIG:
+    case UPDATE_CONFIG:
         return _updateConfig(state, action);
 
     case CONFIG_WILL_LOAD:

react/features/prejoin/actions.js

 /**
  * Action used to start the conference.
  *
+ * @param {Object} options - The config options that override the default ones (if any).
  * @returns {Function}
  */
-export function joinConference() {
+export function joinConference(options?: Object) {
     return {
-        type: PREJOIN_START_CONFERENCE
+        type: PREJOIN_START_CONFERENCE,
+        options
     };
 }
 
         if (audioTrack) {
             await dispatch(replaceLocalTrack(audioTrack, null));
         }
-        dispatch(joinConference());
+
+        dispatch(joinConference({
+            startSilent: true
+        }));
     };
 }
 

react/features/prejoin/middleware.js

 // @flow
 
+import { updateConfig } from '../base/config';
 import { SET_AUDIO_MUTED, SET_VIDEO_MUTED } from '../base/media';
 import { MiddlewareRegistry } from '../base/redux';
 import { updateSettings } from '../base/settings';
         const state = getState();
         const { userSelectedSkipPrejoin } = state['features/prejoin'];
         const localVideoTrack = getLocalVideoTrack(state['features/base/tracks']);
+        const { options } = action;
+
+        options && store.dispatch(updateConfig(options));
 
         userSelectedSkipPrejoin && dispatch(updateSettings({
             userSelectedSkipPrejoin