Fix the reply count for pinned posts (#14744)

store/sqlstore/channel_store.go

@@ -733,7 +733,7 @@ func (s SqlChannelStore) GetPinnedPosts(channelId string) (*model.PostList, *mod
 	pl := model.NewPostList()
 
 	var posts []*model.Post
-	if _, err := s.GetReplica().Select(&posts, "SELECT * FROM Posts WHERE IsPinned = true AND ChannelId = :ChannelId AND DeleteAt = 0 ORDER BY CreateAt ASC", map[string]interface{}{"ChannelId": channelId}); err != nil {
+	if _, err := s.GetReplica().Select(&posts, "SELECT *, (SELECT count(Posts.Id) FROM Posts WHERE Posts.RootId = (CASE WHEN p.RootId = '' THEN p.Id ELSE p.RootId END) AND Posts.DeleteAt = 0) as ReplyCount  FROM Posts p WHERE IsPinned = true AND ChannelId = :ChannelId AND DeleteAt = 0 ORDER BY CreateAt ASC", map[string]interface{}{"ChannelId": channelId}); err != nil {
 		return nil, model.NewAppError("SqlPostStore.GetPinnedPosts", "store.sql_channel.pinned_posts.app_error", nil, err.Error(), http.StatusInternalServerError)
 	}
 	for _, post := range posts {

store/storetest/channel_store.go

@@ -5589,6 +5589,47 @@ func testChannelStoreGetPinnedPosts(t *testing.T, ss store.Store) {
 	pl, errGet = ss.Channel().GetPinnedPosts(o2.Id)
 	require.Nil(t, errGet, errGet)
 	require.Empty(t, pl.Posts, "wasn't supposed to return posts")
+
+	t.Run("with correct ReplyCount", func(t *testing.T) {
+		channelId := model.NewId()
+		userId := model.NewId()
+
+		post1, err := ss.Post().Save(&model.Post{
+			ChannelId: channelId,
+			UserId:    userId,
+			Message:   "message",
+			IsPinned:  true,
+		})
+		require.Nil(t, err)
+		time.Sleep(time.Millisecond)
+
+		post2, err := ss.Post().Save(&model.Post{
+			ChannelId: channelId,
+			UserId:    userId,
+			Message:   "message",
+			IsPinned:  true,
+		})
+		require.Nil(t, err)
+		time.Sleep(time.Millisecond)
+
+		post3, err := ss.Post().Save(&model.Post{
+			ChannelId: channelId,
+			UserId:    userId,
+			ParentId:  post1.Id,
+			RootId:    post1.Id,
+			Message:   "message",
+			IsPinned:  true,
+		})
+		require.Nil(t, err)
+		time.Sleep(time.Millisecond)
+
+		posts, err := ss.Channel().GetPinnedPosts(channelId)
+		require.Nil(t, err)
+		require.Len(t, posts.Posts, 3)
+		require.Equal(t, posts.Posts[post1.Id].ReplyCount, int64(1))
+		require.Equal(t, posts.Posts[post2.Id].ReplyCount, int64(0))
+		require.Equal(t, posts.Posts[post3.Id].ReplyCount, int64(1))
+	})
 }
 
 func testChannelStoreGetPinnedPostCount(t *testing.T, ss store.Store) {