From 44aa582ceb79876f67ddc3ff0bbd454dc6e73f19 Mon Sep 17 00:00:00 2001
From: Michael Schneider <maicki@users.noreply.github.com>
Date: Sun, 13 Nov 2016 17:15:11 -0800
Subject: [PATCH] Fix crash if batch update blocks are nil although method
 declaration allows nullable (#2599)

---
 AsyncDisplayKit/ASCollectionView.mm           |  4 +++-
 AsyncDisplayKit/ASTableNode.mm                |  4 +++-
 AsyncDisplayKitTests/ASCollectionViewTests.mm | 10 ++++++++++
 AsyncDisplayKitTests/ASTableViewTests.m       |  9 +++++++++
 4 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/AsyncDisplayKit/ASCollectionView.mm b/AsyncDisplayKit/ASCollectionView.mm
index 9196567863..f80f476c2c 100644
--- a/AsyncDisplayKit/ASCollectionView.mm
+++ b/AsyncDisplayKit/ASCollectionView.mm
@@ -653,7 +653,9 @@ static NSString * const kCellReuseIdentifier = @"_ASCollectionViewCell";
   ASDisplayNodeAssertMainThread();
   
   [_dataController beginUpdates];
-  updates();
+  if (updates) {
+    updates();
+  }
   [_dataController endUpdatesAnimated:animated completion:completion];
 }
 
diff --git a/AsyncDisplayKit/ASTableNode.mm b/AsyncDisplayKit/ASTableNode.mm
index 3ffe388e1b..48c62cbe9c 100644
--- a/AsyncDisplayKit/ASTableNode.mm
+++ b/AsyncDisplayKit/ASTableNode.mm
@@ -521,7 +521,9 @@ ASEnvironmentCollectionTableSetEnvironmentState(_environmentStateLock)
 - (void)performBatchAnimated:(BOOL)animated updates:(void (^)())updates completion:(void (^)(BOOL))completion
 {
   [self.view beginUpdates];
-  updates();
+  if (updates) {
+    updates();
+  }
   [self.view endUpdatesAnimated:animated completion:completion];
 }
 
diff --git a/AsyncDisplayKitTests/ASCollectionViewTests.mm b/AsyncDisplayKitTests/ASCollectionViewTests.mm
index f0f509195e..51a4804777 100644
--- a/AsyncDisplayKitTests/ASCollectionViewTests.mm
+++ b/AsyncDisplayKitTests/ASCollectionViewTests.mm
@@ -798,4 +798,14 @@
   XCTAssertNotEqualObjects(oldHeader, newHeader);
 }
 
+- (void)testThatNilBatchUpdatesCanBeSubmitted
+{
+  __block ASCollectionViewTestController *testController = [[ASCollectionViewTestController alloc] initWithNibName:nil bundle:nil];
+  __block ASCollectionNode *cn = testController.collectionNode;
+  
+  // Passing nil blocks should not crash
+  [cn performBatchUpdates:nil completion:nil];
+  [cn performBatchAnimated:NO updates:nil completion:nil];
+}
+
 @end
diff --git a/AsyncDisplayKitTests/ASTableViewTests.m b/AsyncDisplayKitTests/ASTableViewTests.m
index 510306547b..8091e7c2af 100644
--- a/AsyncDisplayKitTests/ASTableViewTests.m
+++ b/AsyncDisplayKitTests/ASTableViewTests.m
@@ -705,6 +705,15 @@
   }
 }
 
+- (void)testThatNilBatchUpdatesCanBeSubmitted
+{
+  ASTableNode *node = [[ASTableNode alloc] initWithStyle:UITableViewStylePlain];
+  
+  // Passing nil blocks should not crash
+  [node performBatchUpdates:nil completion:nil];
+  [node performBatchAnimated:NO updates:nil completion:nil];
+}
+
 @end
 
 @implementation UITableView (Testing)