Resolution for issue #5092: Unit test handle checks consider dangling handles to be valid.

runtime/vm/dart_api_impl.cc

Index: runtime/vm/dart_api_impl.cc
diff --git a/runtime/vm/dart_api_impl.cc b/runtime/vm/dart_api_impl.cc
index 22e23911615cecd9d72dcd545b018d2983ff3b1b..e7017cfddfefce0e810db8140fb9521bb33f7486 100644
--- a/runtime/vm/dart_api_impl.cc
+++ b/runtime/vm/dart_api_impl.cc
@@ -534,6 +534,22 @@ Dart_Handle Api::AcquiredError(Isolate* isolate) {
 }
 
 
+bool Api::IsValid(Dart_Handle handle) {
+  Isolate* isolate = Isolate::Current();
+  CHECK_ISOLATE(isolate);
+
+  // Check against all of the handles in the current isolate as well as the
+  // read-only handles.
+  return isolate->thread_registry()->IsValidHandle(handle) ||
+         isolate->api_state()->IsValidPersistentHandle(
+             reinterpret_cast<Dart_PersistentHandle>(handle)) ||
+         isolate->api_state()->IsValidWeakPersistentHandle(
+             reinterpret_cast<Dart_WeakPersistentHandle>(handle)) ||
+         Dart::IsReadOnlyApiHandle(handle) ||
+         Dart::IsReadOnlyHandle(reinterpret_cast<uword>(handle));
+}
+
+
 ApiLocalScope* Api::TopScope(Thread* thread) {
   ASSERT(thread != NULL);
   ApiLocalScope* scope = thread->api_top_scope();
@@ -759,6 +775,11 @@ void FinalizablePersistentHandle::Finalize(
 
 // --- Handles ---
 
+DART_EXPORT bool Dart_IsValid(Dart_Handle handle) {
+  return Api::IsValid(handle);
+}

[siva, 2017/01/20 17:40:03]

Not needed as you have dropped it from the API.

[bkonyi, 2017/01/20 23:07:11]

Done.

+
+
 DART_EXPORT bool Dart_IsError(Dart_Handle handle) {
   return Api::IsError(handle);
 }