Merge pull request artsy#2016 from artsy/ashfurrow-lot-list-perf

Removes old subscriptions to improve lot list scrolling performance

Artsy/View_Controllers/Live_Auctions/LiveAuctionLotListViewController.swift

@@ -44,6 +44,8 @@ class LiveAuctionLotListViewController: UICollectionViewController {
                 return sSelf.stickyCollectionViewLayout.setActiveIndex(nil)
             }
 
+            sSelf.unsubscribeCurrentLotState()
+
             // A lot can be the _current_ lot without being _opened_ yet. We check the current lot state to make sure that the activeIndex of the layout corresponds to the lotState that the cells are using to render themselves.
             sSelf.currentLotStateSubscription = lot.lotStateSignal.subscribe { lotState in
                 let activeIndex: Int? = (lotState == .LiveLot ? sSelf.salesPerson.indexForViewModel(lot) : nil)
@@ -58,7 +60,6 @@ class LiveAuctionLotListViewController: UICollectionViewController {
     }
 
     deinit {
-        currentLotStateSubscription?.unsubscribe()
         unsubscribeCurrentLotState()
     }
 

CHANGELOG.yml

@@ -9,6 +9,8 @@ upcoming:
       - Fixes tableview crasher in onboarding - sarah + maxim
       - Fixes email retrieval from Facebook SDK and removes email confirmation screen - maxim
       - Fixes crasher in onboarding tableview when no selection was made - alloy
+      - Fixes performance issues on the live auctions lot list - ash
+
       - Fixes bug in GeneVC where fetching was starting on page 2 - sarah
       - Update home view artworks rails order - maxim
       - Fix artist link to auction results - alloy