Always check if instance method name collides with superclass static.

pkg/analyzer/lib/src/generated/error_verifier.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.resolver.error_verifier;
 
 import 'dart:collection';
 import "dart:math" as math;
 
 import 'java_engine.dart';
@@ skipping 1400 matching lines @@
    * @param executableElement a non-null [ExecutableElement] to evaluate
    * @param parameters the parameters of the executable element
    * @param errorNameTarget the node to report problems on
    * @return `true` if and only if an error code is generated on the passed node
    */
   bool _checkForAllInvalidOverrideErrorCodesForExecutable(ExecutableElement executableElement, List<ParameterElement> parameters, List<AstNode> parameterLocations, SimpleIdentifier errorNameTarget) {
     //
     // Compute the overridden executable from the InheritanceManager
     //
     List<ExecutableElement> overriddenExecutables = _inheritanceManager.lookupOverrides(_enclosingClass, executableElement.name);
-    if (overriddenExecutables.isEmpty) {
-      // Nothing is overridden, so we just have to check if the new name collides
-      // with a static defined in the superclass.
-      // TODO(paulberry): currently we don't do this check if the new element
-      // overrides a method in an interface (see issue 18947).
-      return _checkForInstanceMethodNameCollidesWithSuperclassStatic(executableElement, errorNameTarget);
+    if (_checkForInstanceMethodNameCollidesWithSuperclassStatic(
+        executableElement, errorNameTarget)) {
+      return true;
     }
     for (ExecutableElement overriddenElement in overriddenExecutables) {
       if (_checkForAllInvalidOverrideErrorCodes(executableElement, overriddenElement, parameters, parameterLocations, errorNameTarget)) {
         return true;
       }
     }
     return false;
   }
 
   /**
@@ skipping 4052 matching lines @@
     toCheck.add(element);
     // type arguments
     if (type is InterfaceType) {
       InterfaceType interfaceType = type;
       for (DartType typeArgument in interfaceType.typeArguments) {
         _addTypeToCheck(typeArgument);
       }
     }
   }
 }