CQ. Fix NPE in OverrideVerifier, when missing name.

Saw a crash in logs: _TypeError: Null check operator used on a null value at OverrideVerifier._isOverride	(override_verifier.dart:91) at OverrideVerifier.visitFieldDeclaration	(override_verifier.dart:43) at FieldDeclarationImpl.accept	(ast.dart:8995) at NodeListImpl.accept	(ast.dart:17222) at ClassDeclarationImpl.visitChildren	(ast.dart:3207) at RecursiveAstVisitor.visitClassDeclaration	(visitor.g.dart:833) at OverrideVerifier.visitClassDeclaration	(override_verifier.dart:26) Change-Id: Ia61c0659b299795b1054840377ed066373cfe1ab Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/456110 Commit-Queue: Konstantin Shcheglov <scheglov@google.com> Reviewed-by: Johnni Winther <johnniwinther@google.com>

Author: scheglov

pkg/analyzer/lib/src/error/override_verifier.dart

@@ -87,11 +87,18 @@ class OverrideVerifier extends RecursiveAstVisitor<void> {
  /// Return `true` if the [member] overrides a member from a superinterface.
  bool _isOverride(ExecutableElement member) {
  var currentClass = _currentClass?.firstFragment;
- if (currentClass != null) {
- var name = Name.forElement(member)!;
- return currentClass.element.getOverridden(name) != null;
- } else {
+ if (currentClass == null) {
  return false;
  }
+
+ var name = Name.forElement(member);
+
+ // We get `null` if the element does not have name.
+ // This was already a parse error, avoid the warning.
+ if (name == null) {
+ return true;
+ }
+
+ return currentClass.element.getOverridden(name) != null;
  }
 }

pkg/analyzer/test/src/diagnostics/override_on_non_overriding_method_test.dart

@@ -2,6 +2,7 @@
 // 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:analyzer/src/dart/error/syntactic_errors.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -80,6 +81,22 @@ class B extends A {
 }''');
  }
 
+ test_class_field_missingName() async {
+ await assertErrorsInCode(
+ r'''
+class A {
+ @override
+ Object? foo,;
+}
+''',
+ [
+ error(WarningCode.unusedField, 6, 0),
+ error(WarningCode.overrideOnNonOverridingField, 32, 3),
+ error(ParserErrorCode.missingIdentifier, 36, 1),
+ ],
+ );
+ }
+
  test_class_implements() async {
  await assertNoErrorsInCode(r'''
 class A {