From 9ba225cde5dd09367a0be75db8af8297a6b4b845 Mon Sep 17 00:00:00 2001
From: Dmitry Batkovich <dmitry.batkovich@jetbrains.com>
Date: Mon, 23 Nov 2015 16:59:10 +0300
Subject: [PATCH] type migration: do not migrate super method if return-type
 isn't same

---
 .../refactoring/typeMigration/Util.java       | 26 ++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/java/java-impl/src/com/intellij/refactoring/typeMigration/Util.java b/java/java-impl/src/com/intellij/refactoring/typeMigration/Util.java
index 43175d7d7c6e..b779fb6e5645 100644
--- a/java/java-impl/src/com/intellij/refactoring/typeMigration/Util.java
+++ b/java/java-impl/src/com/intellij/refactoring/typeMigration/Util.java
@@ -17,8 +17,12 @@ package com.intellij.refactoring.typeMigration;
 
 import com.intellij.psi.*;
 import com.intellij.psi.util.PsiTreeUtil;
+import com.intellij.util.SmartList;
+import com.intellij.util.containers.Queue;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.List;
+
 /**
  * @author db
  * Date: Nov 4, 2004
@@ -39,9 +43,25 @@ public class Util {
   @Nullable
   public static PsiElement normalizeElement(final PsiElement element) {
     if (element instanceof PsiMethod) {
-      final PsiMethod superMethod = ((PsiMethod)element).findDeepestSuperMethod();
-
-      return superMethod == null ? element : superMethod;
+      final PsiMethod method = (PsiMethod)element;
+      final PsiType initialMethodReturnType = method.getReturnType();
+      if (initialMethodReturnType == null) {
+        return null;
+      }
+      final List<PsiMethod> normalized = new SmartList<PsiMethod>();
+      final Queue<PsiMethod> queue = new Queue<PsiMethod>(1);
+      queue.addLast(method);
+      while (!queue.isEmpty()) {
+        final PsiMethod currentMethod = queue.pullFirst();
+        if (initialMethodReturnType.equals(currentMethod.getReturnType())) {
+          for (PsiMethod toConsume : currentMethod.findSuperMethods(false)) {
+            queue.addLast(toConsume);
+          }
+          normalized.add(currentMethod);
+        }
+      }
+      //TODO Dmitry Batkovich multiple result is possible
+      return normalized.isEmpty() ? element : normalized.get(normalized.size() - 1);
     }
     else if (element instanceof PsiParameter && element.getParent() instanceof PsiParameterList) {
       final PsiElement declarationScope = ((PsiParameter)element).getDeclarationScope();