Fix a reference count race with forwarded delegates. (#888)

Author: brianquinlan

pkgs/cupertino_http/CHANGELOG.md

@@ -1,6 +1,7 @@
-## 0.1.2-dev
+## 0.1.2
 
 * Require Dart 2.19
+* Fix a [reference count race with forwarded delegates](https://github.com/dart-lang/http/issues/887).
 
 ## 0.1.1
 

pkgs/cupertino_http/lib/src/cupertino_api.dart

@@ -827,11 +827,9 @@ void _setupDelegation(
     final messageType = message[0];
     final dp = Pointer<ncb.ObjCObject>.fromAddress(message[1] as int);
 
-    final forwardedDelegate =
-        ncb.CUPHTTPForwardedDelegate.castFromPointer(helperLibs, dp,
-            // `CUPHTTPForwardedDelegate` was retained in the delegate so it
-            // only needs to be released.
-            release: true);
+    final forwardedDelegate = ncb.CUPHTTPForwardedDelegate.castFromPointer(
+        helperLibs, dp,
+        retain: true, release: true);
 
     switch (messageType) {
       case ncb.MessageType.RedirectMessage:

pkgs/cupertino_http/src/CUPHTTPClientDelegate.m

@@ -91,6 +91,7 @@ - (void)URLSession:(NSURLSession *)session
   [forwardedRedirect.lock lock];
 
   completionHandler(forwardedRedirect.redirectRequest);
+  [forwardedRedirect release];
 }
 
 - (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)task
@@ -124,8 +125,8 @@ - (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)task
   //
   // See the @interface description for CUPHTTPRedirect.
   [forwardedResponse.lock lock];
-  
   completionHandler(forwardedResponse.disposition);
+  [forwardedResponse release];
 }
 
 
@@ -156,6 +157,7 @@ - (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)task
   //
   // See the @interface description for CUPHTTPRedirect.
   [forwardedData.lock lock];
+  [forwardedData release];
 }
 
 - (void)URLSession:(NSURLSession *)session 
@@ -183,6 +185,7 @@ - (void)URLSession:(NSURLSession *)session
   NSAssert(success, @"Dart_PostCObject_DL failed.");
 
   [forwardedFinishedDownload.lock lock];
+  [forwardedFinishedDownload release];
 }
 
 - (void)URLSession:(NSURLSession *)session
@@ -213,6 +216,7 @@ - (void)URLSession:(NSURLSession *)session
   //
   // See the @interface description for CUPHTTPRedirect.
   [forwardedComplete.lock lock];
+  [forwardedComplete release];
 }
 
 @end