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 ad6daba1a2ddd0a6b6740cc892f3deaf2dad6e28..9a4f823b171ea40d4637d9068fbaa340bcc807c3 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()->IsActivePersistentHandle(

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

I added IsActive(Weak)PersistentHandle to check if the handle is valid and is
not part of the free list.

+             reinterpret_cast<Dart_PersistentHandle>(handle)) ||
+         isolate->api_state()->IsActiveWeakPersistentHandle(
+             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();