From 326eb2242a9c6a3cbcecb590dc086c99f762f00f Mon Sep 17 00:00:00 2001
From: Joram Wilander <jwawilander@gmail.com>
Date: Mon, 14 Jun 2021 08:25:44 -0400
Subject: [PATCH] Change Post.IsFollowing to a pointer and set to nil for
 responses to updates to Posts (#17774)

---
 app/post.go                   | 5 +++++
 app/post_test.go              | 2 +-
 model/post.go                 | 6 ++++--
 store/sqlstore/post_store.go  | 6 ++++--
 store/storetest/post_store.go | 2 +-
 5 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/app/post.go b/app/post.go
index cfcf2f05d3..54f25061c5 100644
--- a/app/post.go
+++ b/app/post.go
@@ -649,6 +649,11 @@ func (a *App) UpdatePost(c *request.Context, post *model.Post, safeUpdate bool)
 
 	rpost = a.PreparePostForClient(rpost, false, true)
 
+	// Ensure IsFollowing is nil since this updated post will be broadcast to all users
+	// and we don't want to have to populate it for every single user and broadcast to each
+	// individually.
+	rpost.IsFollowing = nil
+
 	message := model.NewWebSocketEvent(model.WEBSOCKET_EVENT_POST_EDITED, "", rpost.ChannelId, "", nil)
 	message.Add("post", rpost.ToJson())
 	a.Publish(message)
diff --git a/app/post_test.go b/app/post_test.go
index 9bdc17d162..70f93aef14 100644
--- a/app/post_test.go
+++ b/app/post_test.go
@@ -2080,7 +2080,7 @@ func TestCollapsedThreadFetch(t *testing.T) {
 		require.EqualValues(t, []string{user1.Id}, []string{l.Posts[postRoot.Id].Participants[0].Id})
 		require.Empty(t, l.Posts[postRoot.Id].Participants[0].Email)
 		require.NotZero(t, l.Posts[postRoot.Id].LastReplyAt)
-		require.True(t, l.Posts[postRoot.Id].IsFollowing)
+		require.True(t, *l.Posts[postRoot.Id].IsFollowing)
 
 		// try extended fetch
 		l, err = th.App.GetPostsForChannelAroundLastUnread(channel.Id, user1.Id, 10, 10, true, true, true)
diff --git a/model/post.go b/model/post.go
index ff5795cb4a..dd66d69166 100644
--- a/model/post.go
+++ b/model/post.go
@@ -102,7 +102,7 @@ type Post struct {
 	ReplyCount   int64         `json:"reply_count" db:"-"`
 	LastReplyAt  int64         `json:"last_reply_at" db:"-"`
 	Participants []*User       `json:"participants" db:"-"`
-	IsFollowing  bool          `json:"is_following" db:"-"` // for root posts in collapsed thread mode indicates if the current user is following this thread
+	IsFollowing  *bool         `json:"is_following,omitempty" db:"-"` // for root posts in collapsed thread mode indicates if the current user is following this thread
 	Metadata     *PostMetadata `json:"metadata,omitempty" db:"-"`
 }
 
@@ -207,7 +207,9 @@ func (o *Post) ShallowCopy(dst *Post) error {
 	dst.Participants = o.Participants
 	dst.LastReplyAt = o.LastReplyAt
 	dst.Metadata = o.Metadata
-	dst.IsFollowing = o.IsFollowing
+	if o.IsFollowing != nil {
+		dst.IsFollowing = NewBool(*o.IsFollowing)
+	}
 	dst.RemoteId = o.RemoteId
 	return nil
 }
diff --git a/store/sqlstore/post_store.go b/store/sqlstore/post_store.go
index 5e9440cfa1..bb675c6e89 100644
--- a/store/sqlstore/post_store.go
+++ b/store/sqlstore/post_store.go
@@ -34,7 +34,7 @@ type SqlPostStore struct {
 
 type postWithExtra struct {
 	ThreadReplyCount   int64
-	IsFollowing        bool
+	IsFollowing        *bool
 	ThreadParticipants model.StringArray
 	model.Post
 }
@@ -739,7 +739,9 @@ func (s *SqlPostStore) prepareThreadedResponse(posts []*postWithExtra, extended,
 	}
 	processPost := func(p *postWithExtra) error {
 		p.Post.ReplyCount = p.ThreadReplyCount
-		p.Post.IsFollowing = p.IsFollowing
+		if p.IsFollowing != nil {
+			p.Post.IsFollowing = model.NewBool(*p.IsFollowing)
+		}
 		for _, th := range p.ThreadParticipants {
 			var participant *model.User
 			for _, u := range users {
diff --git a/store/storetest/post_store.go b/store/storetest/post_store.go
index ea547802e0..1ee3eb90e1 100644
--- a/store/storetest/post_store.go
+++ b/store/storetest/post_store.go
@@ -451,7 +451,7 @@ func testPostStoreGetForThread(t *testing.T, ss store.Store) {
 	r1, err := ss.Post().Get(context.Background(), o1.Id, false, true, false, o1.UserId)
 	require.NoError(t, err)
 	require.Equal(t, r1.Posts[o1.Id].CreateAt, o1.CreateAt, "invalid returned post")
-	require.True(t, r1.Posts[o1.Id].IsFollowing)
+	require.True(t, *r1.Posts[o1.Id].IsFollowing)
 }
 
 func testPostStoreGetSingle(t *testing.T, ss store.Store) {