Revert " #4755 Combining consecutive user join/leave system messages to single message and few other changes." (#7072)

* Revert "PLT-6603: Don't return all posts on invalid query. (#7061)"

This reverts commit 25a2013890.

* Revert " #4755 Combining consecutive user join/leave system messages to single message and few other changes. (#5945)"

This reverts commit 8a91235fb3.

store/sql_post_store.go

@@ -97,7 +97,8 @@ func (s SqlPostStore) Save(post *model.Post) StoreChannel {
 		} else {
 			time := post.UpdateAt
 
-			if !post.IsUserActivitySystemMessage() {
+			if post.Type != model.POST_JOIN_LEAVE && post.Type != model.POST_JOIN_CHANNEL && post.Type != model.POST_LEAVE_CHANNEL &&
+				post.Type != model.POST_ADD_REMOVE && post.Type != model.POST_ADD_TO_CHANNEL && post.Type != model.POST_REMOVE_FROM_CHANNEL {
 				s.GetMaster().Exec("UPDATE Channels SET LastPostAt = :LastPostAt, TotalMsgCount = TotalMsgCount + 1 WHERE Id = :ChannelId", map[string]interface{}{"LastPostAt": time, "ChannelId": post.ChannelId})
 			} else {
 				// don't update TotalMsgCount for unimportant messages so that the channel isn't marked as unread
@@ -1354,29 +1355,3 @@ func (s SqlPostStore) GetPostsBatchForIndexing(startTime int64, limit int) Store
 
 	return storeChannel
 }
-
-func (s SqlPostStore) GetLastPostForChannel(channelId string) StoreChannel {
-	storeChannel := make(StoreChannel, 1)
-
-	go func() {
-		result := StoreResult{}
-
-		var post model.Post
-		query := `
-			SELECT * FROM Posts 
-			WHERE ChannelId = :channelId AND DeleteAt = 0
-			ORDER BY CreateAt DESC
-			LIMIT 1
-		`
-
-		if err := s.GetReplica().SelectOne(&post, query, map[string]interface{}{"channelId": channelId}); err != nil {
-			l4g.Error(err)
-		}
-
-		result.Data = &post
-		storeChannel <- result
-		close(storeChannel)
-	}()
-
-	return storeChannel
-}