Fix updating last message when showing deleted status

Closes #9332

packages/rocketchat-lib/server/functions/deleteMessage.js

@@ -31,8 +31,11 @@ RocketChat.deleteMessage = function(message, user) {
 
 	// update last message
 	if (RocketChat.settings.get('Store_Last_Message')) {
-		const lastMessage = RocketChat.models.Messages.getLastMessageSentWithNoTypeByRoomId(message.rid);
-		RocketChat.models.Rooms.setLastMessageById(message.rid, lastMessage);
+		const room = RocketChat.models.Rooms.findOneById(message.rid, { fields: { lastMessage: 1 } });
+		if (!room.lastMessage || room.lastMessage._id === message._id) {
+			const lastMessage = RocketChat.models.Messages.getLastVisibleMessageSentWithNoTypeByRoomId(message.rid, message._id);
+			RocketChat.models.Rooms.setLastMessageById(message.rid, lastMessage);
+		}
 	}
 
 	if (showDeletedStatus) {

packages/rocketchat-lib/server/models/Messages.js

@@ -284,12 +284,17 @@ RocketChat.models.Messages = new class extends RocketChat.models._Base {
 		return this.findOne(query);
 	}
 
-	getLastMessageSentWithNoTypeByRoomId(rid) {
+	getLastVisibleMessageSentWithNoTypeByRoomId(rid, messageId) {
 		const query = {
 			rid,
+			_hidden: { $ne: true },
 			t: { $exists: false }
 		};
 
+		if (messageId) {
+			query._id = { $ne: messageId };
+		}
+
 		const options = {
 			sort: {
 				ts: -1