Properly finalize type with malformed type argument.

runtime/vm/class_finalizer.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/class_finalizer.h"
 
 #include "vm/flags.h"
 #include "vm/heap.h"
 #include "vm/isolate.h"
 #include "vm/longjump.h"
@@ skipping 661 matching lines @@
     ResolveInterfaces(type_class, &visited_interfaces);
     FinalizeTypeParameters(type_class);
   }
 
   // Finalize the current type arguments of the type, which are still the
   // parsed type arguments.
   AbstractTypeArguments& arguments =
       AbstractTypeArguments::Handle(parameterized_type.arguments());
   if (!arguments.IsNull()) {
     intptr_t num_arguments = arguments.Length();
+    AbstractType& type_argument = AbstractType::Handle();
     for (intptr_t i = 0; i < num_arguments; i++) {
-      AbstractType& type_argument = AbstractType::Handle(arguments.TypeAt(i));
+      type_argument = arguments.TypeAt(i);
       type_argument = FinalizeType(cls, type_argument, finalization);
+      if (type_argument.IsMalformed()) {
+        // In production mode, malformed type arguments are mapped to Dynamic.
+        // In checked mode, a type with malformed type arguments is malformed.
+        if (FLAG_enable_type_checks) {
+          const Error& error = Error::Handle(type_argument.malformed_error());
+          const String& type_name = String::Handle(parameterized_type.Name());
+          FinalizeMalformedType(error, cls, parameterized_type, finalization,
+                                "type '%s' has malformed type argument",
+                                type_name.ToCString());
+          return parameterized_type.raw();
+        } else {
+          type_argument = Type::DynamicType();
+        }
+      }
       arguments.SetTypeAt(i, type_argument);
     }
   }
 
   // The finalized type argument vector needs num_type_arguments types.
   const intptr_t num_type_arguments = type_class.NumTypeArguments();
   // The type class has num_type_parameters type parameters.
   const intptr_t num_type_parameters = type_class.NumTypeParameters();
 
   // Initialize the type argument vector.
@@ skipping 791 matching lines @@
 void ClassFinalizer::ReportError(const char* format, ...) {
   va_list args;
   va_start(args, format);
   const Error& error = Error::Handle(
       Parser::FormatError(Script::Handle(), -1, "Error", format, args));
   va_end(args);
   ReportError(error);
 }
 
 }  // namespace dart