Fix un-reblogged status being at wrong position in the home timeline (#5418)

We've changed un-reblogging behavior when we implement Snowflake, to insert un-reblogged status at the position reblogging status existed.

However, our API expects home timeline is ordered by status ids, and max_id/since_id filters by zset score. Due to this, un-reblogged status appears as a last item of result set, and timeline expansion may skips many statuses.

So this reverts that change...reblogged status inserted at corresponding position to its id.

1 files changed, 5 insertions, 4 deletions

diff --git a/app/lib/feed_manager.rb b/app/lib/feed_manager.rb
index 89aeaadcd..dfd11a23b 100644
--- a/app/lib/feed_manager.rb
+++ b/app/lib/feed_manager.rb
@@ -198,10 +198,11 @@ class FeedManager
       # 2. Remove the reblogged status from the `:reblogs` zset.
       redis.zrem(reblog_key, status.reblog_of_id)
 
-      # 3. Add the reblogged status to the feed using the reblogging
-      # status' ID as its score, and the reblogged status' ID as its
-      # value.
-      redis.zadd(timeline_key, status.id, status.reblog_of_id)
+      # 3. Add the reblogged status to the feed.
+      # Note that we can't use old score in here
+      # and it must be an ID of corresponding status
+      # because we need to filter timeline by status ID.
+      redis.zadd(timeline_key, status.reblog_of_id, status.reblog_of_id)
 
       # 4. Remove the reblogging status from the feed (as normal)
     end