[analyzer] copy generic type args when inferring a new function type for an ExecutableElement

pkg/analyzer/lib/src/task/strong_mode.dart

Index: pkg/analyzer/lib/src/task/strong_mode.dart
diff --git a/pkg/analyzer/lib/src/task/strong_mode.dart b/pkg/analyzer/lib/src/task/strong_mode.dart
index 0c53dad08256ede52c81be4c971fb256a8573e4a..f8cb97f6e8964224c15fbab6d0fdc2a9993c3bae 100644
--- a/pkg/analyzer/lib/src/task/strong_mode.dart
+++ b/pkg/analyzer/lib/src/task/strong_mode.dart
@@ -28,7 +28,8 @@ void setParameterType(PropertyAccessorElement element, DartType type) {
       FunctionType functionType = element.type;
       if (functionType is FunctionTypeImpl) {
         element.type =
-            new FunctionTypeImpl(element, functionType.prunedTypedefs);
+            new FunctionTypeImpl(element, functionType.prunedTypedefs)
+              ..typeArguments = functionType.typeArguments;

[Jennifer Messerly, 2015/09/24 22:35:56]

not sure if y'all use cascades, let me know if there's a better way to format
this.

[Brian Wilkerson, 2015/09/24 22:49:27]

I haven't gotten in the habit of using them much, but don't have a problem with
them being used. As for formatting, we always run the formatter over everything
so that formatting is never a question.

       } else {
         assert(false);
       }
@@ -53,7 +54,8 @@ void setReturnType(ExecutableElement element, DartType type) {
     element.returnType = type;
     FunctionType functionType = element.type;
     if (functionType is FunctionTypeImpl) {
-      element.type = new FunctionTypeImpl(element, functionType.prunedTypedefs);
+      element.type = new FunctionTypeImpl(element, functionType.prunedTypedefs)
+        ..typeArguments = functionType.typeArguments;
     } else {
       assert(false);
     }