Await it!

runtime/vm/scopes.cc

Index: runtime/vm/scopes.cc
diff --git a/runtime/vm/scopes.cc b/runtime/vm/scopes.cc
index d9f2df16e615c53eff63ef0c68a131f57344ed50..bab5afbaeeef7446f18464e443e0dce2b12dca8f 100644
--- a/runtime/vm/scopes.cc
+++ b/runtime/vm/scopes.cc
@@ -602,6 +602,27 @@ LocalScope* LocalScope::RestoreOuterScope(const ContextScope& context_scope) {
 }
 
 
+void LocalScope::RecursivelyCaptureAllVariables() {
+  bool found = false;
+  for (intptr_t i = 0; i < num_variables(); i++) {
+    if ((VariableAt(i)->name().raw() == Symbols::StackTraceVar().raw()) ||
+        (VariableAt(i)->name().raw() == Symbols::ExceptionVar().raw())) {
+      // Don't capture those variables as their scope of use can not be
+      // interrupted by await. In other words: There is no way to reach an await
+      // in between assigning them a value and reading the value, as these are
+      // just internals to pass along exception states.
+      continue;
+    }
+    found = CaptureVariable(VariableAt(i)->name());
+    VariableAt(i)->set_is_captured();
+    ASSERT(found);
+  }
+  if (sibling() != NULL) { sibling()->RecursivelyCaptureAllVariables(); }
+  if (child() != NULL) { child()->RecursivelyCaptureAllVariables(); }
+}
+
+
+
 RawContextScope* LocalScope::CreateImplicitClosureScope(const Function& func) {
   static const intptr_t kNumCapturedVars = 1;