Fixes RocketChat#280

Renaming a thread is now possible without losing the capability to navigate.
The navigation from thread to parent only survives the renaming half: The updated name is shown after a refresh, but the link is not clickable.
Considered good enough for the moment

packages/assistify-help-request/server/methods/createRequestFromRoomId.js

@@ -15,9 +15,7 @@ export class CreateRequestFromRoomId extends CreateRequestBase {
 	}
 
 	_getMessageUrl(msgId) {
-		const message = RocketChat.models.Messages.findOneById(msgId);
-		const room = RocketChat.models.Rooms.findOneById(message.rid);
-		return FlowRouter.path(RocketChat.roomTypes.getRouteLink(room.t, room), '', {msg: msgId});
+		return FlowRouter.path('message', {id: msgId});
 	}
 
 	_linkMessages(roomCreated, parentRoom) {
@@ -48,8 +46,8 @@ export class CreateRequestFromRoomId extends CreateRequestBase {
 						name: Meteor.user().username // Use @Name field for navigation
 					}],
 					channels: [{
-						_id: parentRoom._id, // Parent Room ID
-						name: parentRoom.fname || parentRoom.name
+						_id: parentRoom._id // Parent Room ID
+						// name: parentRoom.fname || parentRoom.name
 					}]
 				});
 			// Re-post message in the new room

packages/rocketchat-lib/package.js

@@ -208,6 +208,9 @@ Package.onUse(function(api) {
 	api.addFiles('client/lib/userRoles.js', 'client');
 	api.addFiles('client/lib/Layout.js', 'client');
 
+	// COMMON ROUTES
+	api.addFiles('startup/routes.js');
+
 	// CLIENT METHODS
 	api.addFiles('client/methods/sendMessage.js', 'client');
 	api.addFiles('client/AdminBox.js', 'client');

packages/rocketchat-lib/startup/routes.js

@@ -0,0 +1,33 @@
+/* globals RocketChat */
+
+import {FlowRouter} from 'meteor/kadira:flow-router';
+
+/**
+ * in order to provide links to messages which are stable (e. g. survive renaming a room or changing its type)
+ * we introduce an explicit route. Since this needs to be executable on the client, we provide a method along with it
+ */
+FlowRouter.route('/message/:id', {
+	name: 'message',
+	action(params) {
+		Meteor.call('getCurrentRouteLink', params.id, (err, res) => {
+			if (!err && res) {
+				FlowRouter.go(res);
+			}
+		});
+	}
+});
+
+Meteor.methods({
+	getCurrentRouteLink(messageId) {
+		if (Meteor.isServer) {
+			const message = RocketChat.models.Messages.findOneById(messageId);
+
+			if (message && message.rid) {
+				const room = RocketChat.models.Rooms.findOneById(message.rid);
+				return FlowRouter.path(RocketChat.roomTypes.getRouteLink(room.t, room), '', {msg: message._id});
+			} else {
+				throw new Meteor.Error('invalid message');
+			}
+		}
+	}
+});