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 25a2013890c7e07b4621fa9b18342e7f35363049.

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

This reverts commit 8a91235fb3cdc8d094dbc2eaa0d7baa447132b3c.

3 files changed, 2 insertions, 62 deletions

diff --git a/store/sql_post_store.go b/store/sql_post_store.go
index c66e44274..e89b5e042 100644
--- a/store/sql_post_store.go
+++ b/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
-}
diff --git a/store/sql_post_store_test.go b/store/sql_post_store_test.go
index 761e0dcdf..27e816996 100644
--- a/store/sql_post_store_test.go
+++ b/store/sql_post_store_test.go
@@ -1661,37 +1661,3 @@ func TestPostStoreGetPostsBatchForIndexing(t *testing.T) {
 		}
 	}
 }
-
-func TestGetLastPostForChannel(t *testing.T) {
-	Setup()
-
-	o1 := &model.Post{}
-	o1.ChannelId = model.NewId()
-	o1.UserId = model.NewId()
-	o1.Message = ""
-	o1.Type = model.POST_JOIN_CHANNEL
-
-	o1 = (<-store.Post().Save(o1)).Data.(*model.Post)
-
-	if r1 := <-store.Post().GetLastPostForChannel(o1.ChannelId); r1.Err != nil {
-		t.Fatal(r1.Err)
-	} else {
-		if r1.Data.(*model.Post).Id != o1.Id {
-			t.Fatal("invalid returned post")
-		}
-	}
-
-	o2 := &model.Post{}
-	o2.ChannelId = o1.ChannelId
-	o2.UserId = model.NewId()
-	o2.Message = ""
-
-	o2 = (<-store.Post().Save(o2)).Data.(*model.Post)
-	if r2 := <-store.Post().GetLastPostForChannel(o2.ChannelId); r2.Err != nil {
-		t.Fatal(r2.Err)
-	} else {
-		if r2.Data.(*model.Post).Id != o2.Id {
-			t.Fatal("invalid returned post")
-		}
-	}
-}
diff --git a/store/store.go b/store/store.go
index 9824ec213..d883ea5a2 100644
--- a/store/store.go
+++ b/store/store.go
@@ -170,7 +170,6 @@ type PostStore interface {
 	Overwrite(post *model.Post) StoreChannel
 	GetPostsByIds(postIds []string) StoreChannel
 	GetPostsBatchForIndexing(startTime int64, limit int) StoreChannel
-	GetLastPostForChannel(channelId string) StoreChannel
 }
 
 type UserStore interface {