From 764650fb94933f45f75ec3a509973e5c08eea8f8 Mon Sep 17 00:00:00 2001
From: Nadine Salter <nadi@fb.com>
Date: Thu, 4 Dec 2014 16:28:04 -0800
Subject: [PATCH] _ASTableViewProxy & _ASCollectionViewProxy fixes.

These weren't correctly handling teardown:  nilling the `asyncDelegate`
created a new selector-forwarding NSProxy that crashed and burned
because there was nowhere to forward to.  Nil everything correctly.

Tentatively fixes #121.
---
 AsyncDisplayKit/ASCollectionView.m | 28 ++++++++++++++++++++--------
 AsyncDisplayKit/ASTableView.m      | 24 ++++++++++++++++++------
 2 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/AsyncDisplayKit/ASCollectionView.m b/AsyncDisplayKit/ASCollectionView.m
index 2ab06ff1..cfba0083 100644
--- a/AsyncDisplayKit/ASCollectionView.m
+++ b/AsyncDisplayKit/ASCollectionView.m
@@ -139,20 +139,32 @@ static BOOL _isInterceptedSelector(SEL sel)
 {
   if (_asyncDataSource == asyncDataSource)
     return;
-  
-  _asyncDataSource = asyncDataSource;
-  _proxyDataSource = [[_ASCollectionViewProxy alloc] initWithTarget:_asyncDataSource interceptor:self];
-  super.dataSource = (id<UICollectionViewDataSource>)_proxyDataSource;
+
+  if (asyncDataSource == nil) {
+    _asyncDataSource = nil;
+    _proxyDataSource = nil;
+    super.dataSource = nil;
+  } else {
+    _asyncDataSource = asyncDataSource;
+    _proxyDataSource = [[_ASCollectionViewProxy alloc] initWithTarget:_asyncDataSource interceptor:self];
+    super.dataSource = (id<UICollectionViewDataSource>)_proxyDataSource;
+  }
 }
 
 - (void)setAsyncDelegate:(id<ASCollectionViewDelegate>)asyncDelegate
 {
   if (_asyncDelegate == asyncDelegate)
     return;
-  
-  _asyncDelegate = asyncDelegate;
-  _proxyDelegate = [[_ASCollectionViewProxy alloc] initWithTarget:_asyncDelegate interceptor:self];
-  super.delegate = (id<UICollectionViewDelegate>)_proxyDelegate;
+
+  if (asyncDelegate == nil) {
+    _asyncDelegate = nil;
+    _proxyDelegate = nil;
+    super.delegate = nil;
+  } else {
+    _asyncDelegate = asyncDelegate;
+    _proxyDelegate = [[_ASCollectionViewProxy alloc] initWithTarget:_asyncDelegate interceptor:self];
+    super.delegate = (id<UICollectionViewDelegate>)_proxyDelegate;
+  }
 }
 
 - (ASRangeTuningParameters)rangeTuningParameters
diff --git a/AsyncDisplayKit/ASTableView.m b/AsyncDisplayKit/ASTableView.m
index ee819acd..22932fae 100644
--- a/AsyncDisplayKit/ASTableView.m
+++ b/AsyncDisplayKit/ASTableView.m
@@ -149,9 +149,15 @@ static BOOL _isInterceptedSelector(SEL sel)
   if (_asyncDataSource == asyncDataSource)
     return;
 
-  _asyncDataSource = asyncDataSource;
-  _proxyDataSource = [[_ASTableViewProxy alloc] initWithTarget:_asyncDataSource interceptor:self];
-  super.dataSource = (id<UITableViewDataSource>)_proxyDataSource;
+  if (asyncDataSource == nil) {
+    _asyncDataSource = nil;
+    _proxyDataSource = nil;
+    super.dataSource = nil;
+  } else {
+    _asyncDataSource = asyncDataSource;
+    _proxyDataSource = [[_ASTableViewProxy alloc] initWithTarget:_asyncDataSource interceptor:self];
+    super.dataSource = (id<UITableViewDataSource>)_proxyDataSource;
+  }
 }
 
 - (void)setAsyncDelegate:(id<ASTableViewDelegate>)asyncDelegate
@@ -159,9 +165,15 @@ static BOOL _isInterceptedSelector(SEL sel)
   if (_asyncDelegate == asyncDelegate)
     return;
 
-  _asyncDelegate = asyncDelegate;
-  _proxyDelegate = [[_ASTableViewProxy alloc] initWithTarget:_asyncDelegate interceptor:self];
-  super.delegate = (id<UITableViewDelegate>)_proxyDelegate;
+  if (asyncDelegate == nil) {
+    _asyncDelegate = nil;
+    _proxyDelegate = nil;
+    super.delegate = nil;
+  } else {
+    _asyncDelegate = asyncDelegate;
+    _proxyDelegate = [[_ASTableViewProxy alloc] initWithTarget:_asyncDelegate interceptor:self];
+    super.delegate = (id<UITableViewDelegate>)_proxyDelegate;
+  }
 }
 
 - (ASRangeTuningParameters)rangeTuningParameters