[CFE] Fix crash with ExtensionType and duplicates causing parents not…

… to be set

Change-Id: I107009e585e13082722ff33035a898185b93208a
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/394980
Commit-Queue: Jens Johansen <[email protected]>
Reviewed-by: Johnni Winther <[email protected]>

pkg/front_end/lib/src/kernel/hierarchy/extension_type_members.dart

@@ -186,7 +186,9 @@ class ExtensionTypeMembersNodeBuilder extends MembersNodeBuilder {
             extensionTypeMemberMap: extensionTypeSetableMap);
       }
       if (extensionTypeDeclarationBuilder
-          is SourceExtensionTypeDeclarationBuilder) {
+              is SourceExtensionTypeDeclarationBuilder &&
+          // The check needs parents which aren't set on duplicates.
+          !extensionTypeDeclarationBuilder.isDuplicate) {
         if (getableMember != null &&
             setableMember != null &&
             getableMember.isProperty &&

pkg/front_end/testcases/regress/duplicate_builder_01.dart

@@ -0,0 +1,9 @@
+// Copyright (c) 2024, 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.
+
+int foo = 42;
+
+extension type foo(String foo) {
+  set foo(double x) { }
+}

pkg/front_end/testcases/regress/duplicate_builder_01.dart.strong.expect

@@ -0,0 +1,32 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+//   set foo(double x) { }
+//       ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:16: Error: 'foo' is already declared in this scope.
+// extension type foo(String foo) {
+//                ^^^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:5:5: Context: Previous declaration of 'foo'.
+// int foo = 42;
+//     ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+// extension type foo(String foo) {
+//                           ^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: 'foo' isn't a type.
+//   set foo(double x) { }
+//       ^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Context: This isn't a type.
+// extension type foo(String foo) {
+//                           ^
+//
+import self as self;
+import "dart:core" as core;
+
+static field core::int foo = 42;

pkg/front_end/testcases/regress/duplicate_builder_01.dart.strong.modular.expect

@@ -0,0 +1,32 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+//   set foo(double x) { }
+//       ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:16: Error: 'foo' is already declared in this scope.
+// extension type foo(String foo) {
+//                ^^^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:5:5: Context: Previous declaration of 'foo'.
+// int foo = 42;
+//     ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+// extension type foo(String foo) {
+//                           ^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: 'foo' isn't a type.
+//   set foo(double x) { }
+//       ^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Context: This isn't a type.
+// extension type foo(String foo) {
+//                           ^
+//
+import self as self;
+import "dart:core" as core;
+
+static field core::int foo = 42;

pkg/front_end/testcases/regress/duplicate_builder_01.dart.strong.outline.expect

@@ -0,0 +1,32 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+//   set foo(double x) { }
+//       ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:16: Error: 'foo' is already declared in this scope.
+// extension type foo(String foo) {
+//                ^^^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:5:5: Context: Previous declaration of 'foo'.
+// int foo = 42;
+//     ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+// extension type foo(String foo) {
+//                           ^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: 'foo' isn't a type.
+//   set foo(double x) { }
+//       ^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Context: This isn't a type.
+// extension type foo(String foo) {
+//                           ^
+//
+import self as self;
+import "dart:core" as core;
+
+static field core::int foo;

pkg/front_end/testcases/regress/duplicate_builder_01.dart.strong.transformed.expect

@@ -0,0 +1,32 @@
+library;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+//   set foo(double x) { }
+//       ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:16: Error: 'foo' is already declared in this scope.
+// extension type foo(String foo) {
+//                ^^^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:5:5: Context: Previous declaration of 'foo'.
+// int foo = 42;
+//     ^^^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Error: A class member can't have the same name as the enclosing class.
+// Try renaming the member.
+// extension type foo(String foo) {
+//                           ^
+//
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:8:7: Error: 'foo' isn't a type.
+//   set foo(double x) { }
+//       ^
+// pkg/front_end/testcases/regress/duplicate_builder_01.dart:7:27: Context: This isn't a type.
+// extension type foo(String foo) {
+//                           ^
+//
+import self as self;
+import "dart:core" as core;
+
+static field core::int foo = 42;

pkg/front_end/testcases/regress/duplicate_builder_01.dart.textual_outline.expect

@@ -0,0 +1,5 @@
+int foo = 42;
+
+extension type foo(String foo) {
+  set foo(double x) {}
+}

pkg/front_end/testcases/regress/duplicate_builder_01.dart.textual_outline_modelled.expect

@@ -0,0 +1,5 @@
+extension type foo(String foo) {
+  set foo(double x) {}
+}
+
+int foo = 42;