adds conference to lookup of dial in numbers (#3859)

react/features/invite/actions.js

         const { room } = state['features/base/conference'];
 
         Promise.all([
-            getDialInNumbers(dialInNumbersUrl),
+            getDialInNumbers(dialInNumbersUrl, room, mucURL),
             getDialInConferenceID(dialInConfCodeUrl, room, mucURL)
         ])
             .then(([ dialInNumbers, { conference, id, message } ]) => {

react/features/invite/components/dial-in-summary/DialInSummary.web.js

      * @returns {Promise}
      */
     _getNumbers() {
-        const { dialInNumbersUrl } = config;
+        const { room } = this.props;
+        const { dialInNumbersUrl, hosts } = config;
+        const mucURL = hosts && hosts.muc;
+        let URLSuffix = '';
 
         if (!dialInNumbersUrl) {
             return Promise.reject(this.props.t('info.dialInNotSupported'));
         }
 
-        return fetch(dialInNumbersUrl)
+        // when room and mucURL are available
+        // provide conference when looking up dial in numbers
+
+        if (room && mucURL) {
+            URLSuffix = `?conference=${room}@${mucURL}`;
+        }
+        const conferenceIDURL
+        = `${dialInNumbersUrl}${URLSuffix}`;
+
+        return fetch(conferenceIDURL)
             .then(response => response.json())
             .catch(() => Promise.reject(this.props.t('info.genericError')));
     }

react/features/invite/functions.js

  * Sends a GET request for phone numbers used to dial into a conference.
  *
  * @param {string} url - The service that returns confernce dial-in numbers.
+ * @param {string} roomName - The conference name to find the associated
+ * conference ID.
+ * @param {string} mucURL - In which MUC the conference exists.
  * @returns {Promise} - The promise created by the request. The returned numbers
  * may be an array of numbers or an object with countries as keys and arrays of
  * phone number strings.
  */
-export function getDialInNumbers(url: string): Promise<*> {
-    return doGetJSON(url);
+export function getDialInNumbers(
+        url: string,
+        roomName: string,
+        mucURL: string
+): Promise<*> {
+
+    const fullUrl = `${url}?conference=${roomName}@${mucURL}`;
+
+    return doGetJSON(fullUrl);
 }
 
 /**
             }
 
             numbersPromise = Promise.all([
-                getDialInNumbers(dialInNumbersUrl),
+                getDialInNumbers(dialInNumbersUrl, room, mucURL),
                 getDialInConferenceID(dialInConfCodeUrl, room, mucURL)
             ]).then(([ { defaultCountry, numbers }, {
                 conference, id, message } ]) => {