From 90088a386b2f1457e8579ff7197df85f90677fc4 Mon Sep 17 00:00:00 2001
From: Zichang Guo <zichangguo@google.com>
Date: Wed, 10 Jul 2019 14:43:43 +0000
Subject: [PATCH] [vm/kernel] Remove Function parameters from Local type
 parameters

When calling SetupFunctionParameters, Function type arguments were copied into local type parameters. Local type parameters = previous type parameter + function type parameters.
At BuildTypeParameterType(), local type parameters contains duplicated type parameter from function, which ends up with returning wrong type.

Bug: https://github.com/dart-lang/sdk/issues/37382
Change-Id: I8f486b0b9a9120845349fe1734bbfcc35f1126a1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/108501
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Commit-Queue: Zichang Guo <zichangguo@google.com>
---
 runtime/tests/vm/dart/regress_37382_test.dart      | 14 ++++++++++++++
 .../compiler/frontend/kernel_translation_helper.cc |  4 +---
 2 files changed, 15 insertions(+), 3 deletions(-)
 create mode 100644 runtime/tests/vm/dart/regress_37382_test.dart

diff --git a/runtime/tests/vm/dart/regress_37382_test.dart b/runtime/tests/vm/dart/regress_37382_test.dart
new file mode 100644
index 00000000000..e0d818cc74d
--- /dev/null
+++ b/runtime/tests/vm/dart/regress_37382_test.dart
@@ -0,0 +1,14 @@
+// Copyright (c) 2019, 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.
+
+import 'package:expect/expect.dart';
+
+class A<X, Y> {
+  R f<R>(R Function<S, T>(A<S, T>) t) => t<X, Y>(this);
+}
+
+main() {
+  A<num, num> a = A<int, int>();
+  Expect.equals(a.f.runtimeType.toString(), '<R>(<S, T>(A<S, T>) => R) => R');
+}
diff --git a/runtime/vm/compiler/frontend/kernel_translation_helper.cc b/runtime/vm/compiler/frontend/kernel_translation_helper.cc
index 938a22ac1af..ea6cf244105 100644
--- a/runtime/vm/compiler/frontend/kernel_translation_helper.cc
+++ b/runtime/vm/compiler/frontend/kernel_translation_helper.cc
@@ -3124,9 +3124,7 @@ void TypeTranslator::SetupFunctionParameters(
     function_node_helper->SetJustRead(FunctionNodeHelper::kTypeParameters);
   }
 
-  ActiveTypeParametersScope scope(
-      active_class_, &function,
-      TypeArguments::Handle(Z, function.type_parameters()), Z);
+  ActiveTypeParametersScope scope(active_class_, function, Z);
 
   function_node_helper->ReadUntilExcluding(
       FunctionNodeHelper::kPositionalParameters);