Fix for use-after-free of reload context

runtime/vm/unit_test.cc

 // Copyright (c) 2012, 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/unit_test.h"
 
 #include <stdio.h>
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
@@ skipping 251 matching lines @@
   // Store the new script in TLS.
   OSThread::SetThreadLocal(script_reload_key, reinterpret_cast<uword>(script));
 }
 
 
 Dart_Handle TestCase::TriggerReload() {
   Isolate* isolate = Isolate::Current();
 
   {
     TransitionNativeToVM transition(Thread::Current());
-    isolate->ReloadSources(/* test_mode = */ true);
+    isolate->ReloadSources(/* dont_delete_reload_context = */ true);
   }
 
   return Dart_FinalizeLoading(false);
 }
 
 
 Dart_Handle TestCase::GetReloadErrorOrRootLibrary() {
   Isolate* isolate = Isolate::Current();
 
-  if (isolate->reload_context() != NULL) {
-    // We should only have a reload context hanging around if an error occurred.
-    ASSERT(isolate->reload_context()->has_error());
+  if (isolate->reload_context() != NULL &&
+      isolate->reload_context()->has_error()) {
     // Return a handle to the error.
     return Api::NewHandle(Thread::Current(),
                           isolate->reload_context()->error());
   }
   return Dart_RootLibrary();
 }
 
 
 Dart_Handle TestCase::ReloadTestScript(const char* script) {
   SetReloadTestScript(script);
 
   Dart_Handle result = TriggerReload();
   if (Dart_IsError(result)) {
     return result;
   }
 
-  return GetReloadErrorOrRootLibrary();
+  result = GetReloadErrorOrRootLibrary();
+
+  Isolate* isolate = Isolate::Current();
+  if (isolate->reload_context() != NULL) {
+    isolate->DeleteReloadContext();
+  }
+
+  return result;
 }
 
 
 #endif  // !PRODUCT
 
 
 Dart_Handle TestCase::LoadCoreTestScript(const char* script,
                                          Dart_NativeEntryResolver resolver) {
   return LoadTestScript(script, resolver, CORELIB_TEST_URI);
 }
@@ skipping 141 matching lines @@
   }
   // Copy the remainder of in to out.
   while (*in != '\0') {
     *out++ = *in++;
   }
   *out = '\0';
 }
 
 
 }  // namespace dart