Properly restore context when leaving visitor functions in ErrorVerifier.

pkg/analyzer/test/generated/compile_time_error_code_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.compile_time_error_code_test;
 
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/parser.dart' show ParserErrorCode;
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 2703 matching lines @@
     resolve(source);
     assertErrors(source, [CompileTimeErrorCode.INVALID_URI]);
   }
 
   void test_invalidUri_part() {
     Source source = addSource("part 'ht:';");
     resolve(source);
     assertErrors(source, [CompileTimeErrorCode.INVALID_URI]);
   }
 
+  void test_isInConstInstanceCreation_restored() {
+    // If ErrorVerifier._isInConstInstanceCreation is not properly restored on
+    // exit from visitInstanceCreationExpression, the error at (1) will be
+    // treated as a warning rather than an error.
+    Source source = addSource(r'''
+class Foo<T extends num> {
+  const Foo(x, y);
+}
+const x = const Foo<int>(const Foo<int>(0, 1),
+    const <Foo<String>>[]); // (1)
+''');
+    resolve(source);
+    assertErrors(source, [CompileTimeErrorCode.TYPE_ARGUMENT_NOT_MATCHING_BOUNDS]);
+    verify([source]);
+  }
+
+  void test_isInInstanceVariableInitializer_restored() {
+    // If ErrorVerifier._isInInstanceVariableInitializer is not properly
+    // restored on exit from visitVariableDeclaration, the error at (1)
+    // won't be detected.
+    Source source = addSource(r'''
+class Foo {
+  var bar;
+  Map foo = {
+    'bar': () {
+        var _bar;
+    },
+    'bop': _foo // (1)
+  };
+  _foo() {
+  }
+}''');
+    resolve(source);
+    assertErrors(source, [CompileTimeErrorCode.IMPLICIT_THIS_REFERENCE_IN_INITIALIZER]);
+    verify([source]);
+  }
+
   void test_labelInOuterScope() {
     Source source = addSource(r'''
 class A {
   void m(int i) {
     l: while (i > 0) {
       void f() {
         break l;
       };
     }
   }
@@ skipping 1989 matching lines @@
   void _check_wrongNumberOfParametersForOperator1(String name) {
     _check_wrongNumberOfParametersForOperator(name, "");
     _check_wrongNumberOfParametersForOperator(name, "a, b");
   }
 }
 
 main() {
   _ut.groupSep = ' | ';
   runReflectiveTests(CompileTimeErrorCodeTest);
 }