Merge pull request #7535 from RocketChat/fix-preview-channel

[FIX] Fix Join Channel Without Preview Room Permission

packages/rocketchat-ui/client/lib/RoomHistoryManager.js

@@ -51,11 +51,12 @@ export const RoomHistoryManager = new class {
 			typeName = (curRoomDoc != null ? curRoomDoc.t : undefined) + (curRoomDoc != null ? curRoomDoc.name : undefined);
 		}
 
-		return Meteor.call('loadHistory', rid, ts, limit, ls, function(err, result) {
+		Meteor.call('loadHistory', rid, ts, limit, ls, function(err, result) {
 			if (err) {
 				return;
 			}
 			let previousHeight;
+			const {messages = []} = result;
 			room.unreadNotLoaded.set(result.unreadNotLoaded);
 			room.firstUnread.set(result.firstUnread);
 
@@ -64,7 +65,7 @@ export const RoomHistoryManager = new class {
 				previousHeight = wrapper.scrollHeight;
 			}
 
-			result.messages.forEach(item => {
+			messages.forEach(item => {
 				if (item.t !== 'command') {
 					const roles = [
 						(item.u && item.u._id && UserRoles.findOne(item.u._id, { fields: { roles: 1 }})) || {},
@@ -87,8 +88,8 @@ export const RoomHistoryManager = new class {
 
 			room.isLoading.set(false);
 			if (room.loaded == null) { room.loaded = 0; }
-			room.loaded += result.messages.length;
-			if (result.messages.length < limit) {
+			room.loaded += messages.length;
+			if (messages.length < limit) {
 				return room.hasMore.set(false);
 			}
 		});