From 29a82d744dc53232a2552d5a40cd873c00cc82a9 Mon Sep 17 00:00:00 2001
From: Michelle Deng <mdeng@instagram.com>
Date: Fri, 2 Feb 2018 07:04:25 -0800
Subject: [PATCH] Revert D6871289: [IGListKit][PR] Removed unnecessary nil
 check on transitionDelegate

Summary:
This reverts commit 7ccf5a286ab4ee63bf72273142857496ce62b6f4

bypass-lint

An infra SEV is better than not reverting this diff.
If you copy this password, see you in SEV Review!
cause_a_sev_many_files

Differential Revision:
D6871289

Original commit changeset: 7ccf5a286ab4

fbshipit-source-id: e75cc7bd4a378e1092f4a01be3104fddb336759a
---
 CHANGELOG.md                                  |  2 ++
 .../Internal/IGListAdapter+UICollectionView.m | 22 ++++++++++++-------
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 84b9d906..766c7071 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,8 @@ The changelog for `IGListKit`. Also see the [releases](https://github.com/instag
 
 - Reordered position of intercepted selector in `IGListAdapterProxy`'s `isInterceptedSelector` method to reduce overall consumption of compare. [zhongwuzw](https://github.com/zhongwu) [(#1055)](https://github.com/Instagram/IGListKit/pull/1055)
 
+- Made IGListTransitionDelegate inherited from NSObject. [Igor Vasilenko](https://github.com/vasilenkoigor) [(#1075)](https://github.com/Instagram/IGListKit/pull/1075)
+
 ### Fixes
 
 - Duplicate objects for initial data source setup filtered out. [Mikhail Vashlyaev](https://github.com/yemodin) [(#993](https://github.com/Instagram/IGListKit/pull/993)
diff --git a/Source/Internal/IGListAdapter+UICollectionView.m b/Source/Internal/IGListAdapter+UICollectionView.m
index 2ff1d47a..5cfa3df0 100644
--- a/Source/Internal/IGListAdapter+UICollectionView.m
+++ b/Source/Internal/IGListAdapter+UICollectionView.m
@@ -218,10 +218,13 @@
                    customizedInitialLayoutAttributes:(UICollectionViewLayoutAttributes *)attributes
                                          atIndexPath:(NSIndexPath *)indexPath {
     IGListSectionController *sectionController = [self sectionControllerForSection:indexPath.section];
-    return [sectionController.transitionDelegate listAdapter:self
-                           customizedInitialLayoutAttributes:attributes
-                                           sectionController:sectionController
-                                                     atIndex:indexPath.item];
+    if (sectionController.transitionDelegate) {
+        return [sectionController.transitionDelegate listAdapter:self
+                               customizedInitialLayoutAttributes:attributes
+                                               sectionController:sectionController
+                                                         atIndex:indexPath.item];
+    }
+    return attributes;
 }
 
 - (UICollectionViewLayoutAttributes *)collectionView:(UICollectionView *)collectionView
@@ -229,10 +232,13 @@
                      customizedFinalLayoutAttributes:(UICollectionViewLayoutAttributes *)attributes
                                          atIndexPath:(NSIndexPath *)indexPath {
     IGListSectionController *sectionController = [self sectionControllerForSection:indexPath.section];
-    return [sectionController.transitionDelegate listAdapter:self
-                             customizedFinalLayoutAttributes:attributes
-                                           sectionController:sectionController
-                                                     atIndex:indexPath.item];
+    if (sectionController.transitionDelegate) {
+        return [sectionController.transitionDelegate listAdapter:self
+                                 customizedFinalLayoutAttributes:attributes
+                                               sectionController:sectionController
+                                                         atIndex:indexPath.item];
+    }
+    return attributes;
 }
 
 @end