[analyzer] Fix crash with improperly nested named parameters.

Fixes #61066.

Bug: #61066
Change-Id: I97f9882f99fa8f8cfad9c96c10d0025f7e6d1050
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/439000
Reviewed-by: Konstantin Shcheglov <[email protected]>
Auto-Submit: Paul Berry <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441

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

@@ -340,7 +340,9 @@ abstract class BaseDeprecatedMemberUseVerifier {
           namedParameters = {};
           for (var parameter in parameters) {
             if (parameter.isNamed) {
-              namedParameters[parameter.name3!] = parameter;
+              if (parameter.name3 case var name?) {
+                namedParameters[name] = parameter;
+              }
             }
           }
         }

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

@@ -4,6 +4,7 @@
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/error/codes.dart';
+import 'package:analyzer/src/generated/parser.dart';
 import 'package:analyzer/utilities/package_config_file_builder.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
@@ -688,6 +689,31 @@ import 'package:aaa/a.dart';
     );
   }
 
+  test_incorrectlyNestedNamedParameterDeclaration() async {
+    // This is a regression test; previously this code would cause an analyzer
+    // crash in DeprecatedMemberUseVerifier.
+    await assertErrorsInCode(
+      r'''
+class C {
+  final String x;
+  final bool y;
+
+  const C({
+    required this.x,
+    {this.y = false}
+  });
+}
+
+const z = C(x: '');
+''',
+      [
+        error(CompileTimeErrorCode.FINAL_NOT_INITIALIZED_CONSTRUCTOR_1, 53, 1),
+        error(ParserErrorCode.MISSING_IDENTIFIER, 82, 1),
+        error(ParserErrorCode.EXPECTED_TOKEN, 82, 1),
+      ],
+    );
+  }
+
   test_inDeprecatedClass() async {
     await assertNoErrorsInCode2(
       externalCode: r'''
@@ -1330,6 +1356,28 @@ class B = Object with A;
 ''');
   }
 
+  test_namedParameterMissingName() async {
+    // This is a regression test; previously this code would cause an analyzer
+    // crash in DeprecatedMemberUseVerifier.
+    await assertErrorsInCode(
+      r'''
+class C {
+  const C({this.});
+}
+var z = C(x: '');
+''',
+      [
+        error(
+          CompileTimeErrorCode.INITIALIZING_FORMAL_FOR_NON_EXISTENT_FIELD,
+          21,
+          5,
+        ),
+        error(ParserErrorCode.MISSING_IDENTIFIER, 26, 1),
+        error(CompileTimeErrorCode.UNDEFINED_NAMED_PARAMETER, 42, 1),
+      ],
+    );
+  }
+
   test_operator() async {
     await assertErrorsInCode2(
       externalCode: r'''