Fix regression on the nil delegate #706

Author: Rui Peres

AsyncDisplayKit/ASCollectionView.mm

@@ -202,6 +202,12 @@ - (instancetype)initWithFrame:(CGRect)frame collectionViewLayout:(UICollectionVi
   // and should not trigger a relayout.
   _ignoreMaxSizeChange = CGSizeEqualToSize(_maxSizeForNodesConstrainedSize, CGSizeZero);
 
+  _proxyDelegate = [[_ASCollectionViewProxy alloc] initWithTarget:[NSNull null] interceptor:self];
+  super.delegate = (id<UICollectionViewDelegate>)_proxyDelegate;
+  
+  _proxyDataSource = [[_ASCollectionViewProxy alloc] initWithTarget:[NSNull null] interceptor:self];
+  super.dataSource = (id<UICollectionViewDataSource>)_proxyDataSource;
+  
   self.backgroundColor = [UIColor whiteColor];
 
   [self registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"_ASCollectionViewCell"];
@@ -253,10 +259,10 @@ - (void)setAsyncDataSource:(id<ASCollectionViewDataSource>)asyncDataSource
   // the (common) case of nilling the asyncDataSource in the ViewController's dealloc. In this case our _asyncDataSource
   // will return as nil (ARC magic) even though the _proxyDataSource still exists. It's really important to nil out
   // super.dataSource in this case because calls to _ASTableViewProxy will start failing and cause crashes.
+  _asyncDataSource = nil;
 
   if (asyncDataSource == nil) {
     super.dataSource = nil;
-    _asyncDataSource = nil;
     _proxyDataSource = nil;
     _asyncDataSourceImplementsConstrainedSizeForNode = NO;
   } else {
@@ -278,10 +284,11 @@ - (void)setAsyncDelegate:(id<ASCollectionViewDelegate>)asyncDelegate
   // will return as nil (ARC magic) even though the _proxyDelegate still exists. It's really important to nil out
   // super.delegate in this case because calls to _ASTableViewProxy will start failing and cause crashes.
 
+  // order is important here, the delegate must be callable while nilling super.delegate to avoid random crashes
+  // in UIScrollViewAccessibility.
+  super.delegate = nil;
+
   if (asyncDelegate == nil) {
-    // order is important here, the delegate must be callable while nilling super.delegate to avoid random crashes
-    // in UIScrollViewAccessibility.
-    super.delegate = nil;
     _asyncDelegate = nil;
     _proxyDelegate = nil;
     _asyncDelegateImplementsInsetSection = NO;

AsyncDisplayKit/ASTableView.mm

@@ -218,6 +218,12 @@ - (void)configureWithAsyncDataFetching:(BOOL)asyncDataFetchingEnabled
   // If the initial size is 0, expect a size change very soon which is part of the initial configuration
   // and should not trigger a relayout.
   _ignoreMaxWidthChange = (_maxWidthForNodesConstrainedSize == 0);
+  
+  _proxyDelegate = [[_ASTableViewProxy alloc] initWithTarget:[NSNull null] interceptor:self];
+  super.delegate = (id<UITableViewDelegate>)_proxyDelegate;
+  
+  _proxyDataSource = [[_ASTableViewProxy alloc] initWithTarget:[NSNull null] interceptor:self];
+  super.dataSource = (id<UITableViewDataSource>)_proxyDataSource;
 }
 
 - (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style
@@ -279,8 +285,9 @@ - (void)setAsyncDataSource:(id<ASTableViewDataSource>)asyncDataSource
   // will return as nil (ARC magic) even though the _proxyDataSource still exists. It's really important to nil out
   // super.dataSource in this case because calls to _ASTableViewProxy will start failing and cause crashes.
 
+  super.dataSource = nil;
+
   if (asyncDataSource == nil) {
-    super.dataSource = nil;
     _asyncDataSource = nil;
     _proxyDataSource = nil;
   } else {
@@ -297,12 +304,13 @@ - (void)setAsyncDelegate:(id<ASTableViewDelegate>)asyncDelegate
   // will return as nil (ARC magic) even though the _proxyDelegate still exists. It's really important to nil out
   // super.delegate in this case because calls to _ASTableViewProxy will start failing and cause crashes.
 
+  // order is important here, the delegate must be callable while nilling super.delegate to avoid random crashes
+  // in UIScrollViewAccessibility.
+  super.delegate = nil;
+
   if (asyncDelegate == nil) {
-    // order is important here, the delegate must be callable while nilling super.delegate to avoid random crashes
-    // in UIScrollViewAccessibility.
-    super.delegate = nil;
     _asyncDelegate = nil;
-    _proxyDelegate = nil; 
+    _proxyDelegate = nil;
   } else {
     _asyncDelegate = asyncDelegate;
     _proxyDelegate = [[_ASTableViewProxy alloc] initWithTarget:asyncDelegate interceptor:self];