Issue 20358. Don't report referenced names of named parameters in named expressions as possible sha…

pkg/analysis_server/lib/src/services/refactoring/rename_local.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 services.src.refactoring.rename_local;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol.dart' hide Element;
 import 'package:analysis_server/src/services/correction/status.dart';
@@ skipping 85 matching lines @@
     if (unit == null) {
       return;
     }
     // check for conflicts in the unit
     SourceRange elementRange = element.visibleRange;
     unit.accept(new _ConflictValidatorVisitor(this, result, elementRange));
   }
 }
 
 
-class _ConflictValidatorVisitor extends RecursiveAstVisitor<Object> {
+class _ConflictValidatorVisitor extends RecursiveAstVisitor {
   final RenameLocalRefactoringImpl refactoring;
   final RefactoringStatus result;
   final SourceRange elementRange;
 
   _ConflictValidatorVisitor(this.refactoring, this.result, this.elementRange);
 
   @override
-  Object visitSimpleIdentifier(SimpleIdentifier node) {
+  visitSimpleIdentifier(SimpleIdentifier node) {
     Element nodeElement = node.bestElement;
     String newName = refactoring.newName;
     if (nodeElement != null && nodeElement.name == newName) {
       // duplicate declaration
       if (haveIntersectingRanges(refactoring.element, nodeElement)) {
         String nodeKind = nodeElement.kind.displayName;
         String message = "Duplicate ${nodeKind} '$newName'.";
         result.addError(message, new Location.fromElement(nodeElement));
-        return null;
+        return;
       }
       // shadowing referenced element
-      if (elementRange.contains(node.offset) && !node.isQualified) {
+      if (elementRange.contains(node.offset) &&
+          !node.isQualified &&
+          !_isNamedExpressionName(node)) {
         nodeElement = getSyntheticAccessorVariable(nodeElement);
         String nodeKind = nodeElement.kind.displayName;
         String nodeName = getElementQualifiedName(nodeElement);
         String nameElementSourceName = nodeElement.source.shortName;
         String refKind = refactoring.element.kind.displayName;
         String message =
             'Usage of $nodeKind "$nodeName" declared in '
                 '"$nameElementSourceName" will be shadowed by renamed $refKind.';
         result.addError(message, new Location.fromNode(node));
       }
     }
-    return null;
+  }
+
+  static bool _isNamedExpressionName(SimpleIdentifier node) {
+    return node.parent is Label && node.parent.parent is NamedExpression;
   }
 }