unimplement: do not delete methods which override super methods (IDEA-58918)

java/java-impl/src/com/intellij/codeInspection/actions/UnimplementInterfaceAction.java

@@ -25,6 +25,10 @@ import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NotNull;
 
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
 public class UnimplementInterfaceAction implements IntentionAction {
   private String myName = "Interface";
 
@@ -86,8 +90,13 @@ public class UnimplementInterfaceAction implements IntentionAction {
 
     psiReference.getElement().delete();
 
+    final Set<PsiMethod> superMethods = new HashSet<PsiMethod>();
+    for (PsiClass aClass : psiClass.getSupers()) {
+      Collections.addAll(superMethods, aClass.getAllMethods());
+    }
     final PsiMethod[] psiMethods = targetClass.getAllMethods();
     for (PsiMethod psiMethod : psiMethods) {
+      if (superMethods.contains(psiMethod)) continue;
       final PsiMethod[] implementingMethods = psiClass.findMethodsBySignature(psiMethod, false);
       for (PsiMethod implementingMethod : implementingMethods) {
         implementingMethod.delete();

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unimplement/after2String.java

@@ -0,0 +1,8 @@
+// "Unimplement Interface" "true"
+class A {
+  public String toString() {
+    return super.toString();
+  }
+}
+
+interface II {}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unimplement/before2String.java

@@ -0,0 +1,8 @@
+// "Unimplement Interface" "true"
+class A implements I<caret>I {
+  public String toString() {
+    return super.toString();
+  }
+}
+
+interface II {}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/quickFix/UnimplementIntentionTest.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2000-2010 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.codeInsight.daemon.quickFix;
+
+public class UnimplementIntentionTest extends LightQuickFixTestCase {
+
+  public void test() throws Exception { doAllTests(); }
+
+  protected String getBasePath() {
+    return "/codeInsight/daemonCodeAnalyzer/quickFix/unimplement";
+  }
+
+}
+