Prevent conflict between parameter names and local function names.

pkg/analyzer/test/generated/non_error_resolver_test.dart

 // Copyright (c) 2014, 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.
 
 library engine.non_error_resolver_test;
 
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/parser.dart' show ParserErrorCode;
@@ skipping 3367 matching lines @@
   void test_optionalParameterInOperator_required() {
     Source source = addSource(r'''
 class A {
   operator +(p) {}
 }''');
     resolve(source);
     assertNoErrors(source);
     verify([source]);
   }
 
+  void test_parameterScope_local() {
+    // Parameter names shouldn't conflict with the name of the function they
+    // are enclosed in.
+    Source source = addSource(r'''
+f() {
+  g(g) {
+    h(g);
+  }
+}
+h(x) {}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
+  void test_parameterScope_method() {
+    // Parameter names shouldn't conflict with the name of the function they
+    // are enclosed in.
+    Source source = addSource(r'''
+class C {
+  g(g) {
+    h(g);
+  }
+}
+h(x) {}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
+  void test_parameterScope_toplevel() {
+    // Parameter names shouldn't conflict with the name of the function they
+    // are enclosed in.
+    Source source = addSource(r'''
+g(g) {
+  h(g);
+}
+h(x) {}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_prefixCollidesWithTopLevelMembers() {
     addNamedSource("/lib.dart", r'''
 library lib;
 class A {}''');
     Source source = addSource(r'''
 import 'lib.dart' as p;
 typedef P();
 p2() {}
 var p3;
 class p4 {}
@@ skipping 1296 matching lines @@
 
   void _check_wrongNumberOfParametersForOperator1(String name) {
     _check_wrongNumberOfParametersForOperator(name, "a");
   }
 }
 
 main() {
   _ut.groupSep = ' | ';
   runReflectiveTests(NonErrorResolverTest);
 }