Fix for use-after-free of reload context

runtime/vm/isolate.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 1067 matching lines @@
 #else
   return false;
 #endif
 }
 
 
 #ifndef PRODUCT
 void Isolate::ReportReloadError(const Error& error) {
   ASSERT(IsReloading());
   reload_context_->AbortReload(error);
+}
+
+
+void Isolate::ReloadSources(bool dont_delete_reload_context) {
+  ASSERT(!IsReloading());
+  has_attempted_reload_ = true;
+  reload_context_ = new IsolateReloadContext(this);
+  reload_context_->StartReload();
+  if (dont_delete_reload_context) {
+    // Unit tests use the reload context later. Caller is responsible
+    // for deleting the context.
+    return;
+  }
+  DeleteReloadContext();
+}
+
+
+void Isolate::DeleteReloadContext() {
   delete reload_context_;
   reload_context_ = NULL;
 }
-
-
-void Isolate::ReloadSources(bool test_mode) {
-  ASSERT(!IsReloading());
-  has_attempted_reload_ = true;
-  reload_context_ = new IsolateReloadContext(this, test_mode);
-  reload_context_->StartReload();
-}
 #endif  // !PRODUCT
 
 
 void Isolate::DoneFinalizing() {
   NOT_IN_PRODUCT(
     if (IsReloading()) {
       reload_context_->FinishReload();
-      if (reload_context_->has_error() && reload_context_->test_mode()) {
-        // If the reload has an error and we are in test mode keep the reload
-        // context on the isolate so that it can be used by unit tests.
-        return;
-      }
       if (reload_context_->has_error()) {
         // Remember the reload error.
         sticky_reload_error_ = reload_context_->error();
-      }
-      if (!reload_context_->has_error()) {
+      } else {
         reload_context_->ReportSuccess();
       }
-      delete reload_context_;
-      reload_context_ = NULL;
     }
   )
 }
 
 
 
 bool Isolate::MakeRunnable() {
   ASSERT(Isolate::Current() == NULL);
 
   MutexLocker ml(mutex_);
@@ skipping 1744 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart