rename method: conflict on final override (IDEA-63845)

java/java-impl/src/com/intellij/refactoring/rename/RenameJavaMethodProcessor.java

@@ -33,6 +33,7 @@ import com.intellij.refactoring.RefactoringBundle;
 import com.intellij.refactoring.listeners.RefactoringElementListener;
 import com.intellij.refactoring.util.ConflictsUtil;
 import com.intellij.refactoring.util.MoveRenameUsageInfo;
+import com.intellij.refactoring.util.RefactoringUIUtil;
 import com.intellij.refactoring.util.RefactoringUtil;
 import com.intellij.usageView.UsageInfo;
 import com.intellij.util.IncorrectOperationException;
@@ -147,6 +148,27 @@ public class RenameJavaMethodProcessor extends RenameJavaMemberProcessor {
     findSubmemberHidesMemberCollisions(methodToRename, newName, result);
     findMemberHidesOuterMemberCollisions((PsiMethod) element, newName, result);
     findCollisionsAgainstNewName(methodToRename, newName, result);
+    final PsiClass containingClass = methodToRename.getContainingClass();
+    if (containingClass != null) {
+      final PsiMethod patternMethod = (PsiMethod)methodToRename.copy();
+      try {
+        patternMethod.setName(newName);
+        final PsiMethod methodInBaseClass = containingClass.findMethodBySignature(patternMethod, true);
+        if (methodInBaseClass != null && methodInBaseClass.getContainingClass() != containingClass) {
+          if (methodInBaseClass.hasModifierProperty(PsiModifier.FINAL)) {
+            result.add(new UnresolvableCollisionUsageInfo(methodInBaseClass, methodToRename) {
+              @Override
+              public String getDescription() {
+                return "Renaming method will override final \"" + RefactoringUIUtil.getDescription(methodInBaseClass, true) + "\"";
+              }
+            });
+          }
+        }
+      }
+      catch (IncorrectOperationException e) {
+        LOG.error(e);
+      }
+    }
   }
 
   public void findExistingNameConflicts(final PsiElement element, final String newName, final MultiMap<PsiElement, String> conflicts) {

java/java-tests/testData/refactoring/renameMethod/multi/rename2OverrideFinal/after/p/A.java

@@ -0,0 +1,16 @@
+package p;
+public class A {
+
+        public final void finalMethod() {
+        }
+}
+
+class B extends A implements I {
+
+        public void method() {
+        }
+}
+
+interface I {
+        void method();
+}

java/java-tests/testData/refactoring/renameMethod/multi/rename2OverrideFinal/before/p/A.java

@@ -0,0 +1,16 @@
+package p;
+public class A {
+
+        public final void finalMethod() {
+        }
+}
+
+class B extends A implements I {
+
+        public void method() {
+        }
+}
+
+interface I {
+        void method();
+}

java/java-tests/testSrc/com/intellij/refactoring/RenameMethodMultiTest.java

@@ -8,6 +8,7 @@ import com.intellij.psi.PsiMethod;
 import com.intellij.psi.search.GlobalSearchScope;
 import com.intellij.refactoring.rename.RenameProcessor;
 import com.intellij.JavaTestUtil;
+import org.junit.Assert;
 
 /**
  * @author dsl
@@ -39,6 +40,19 @@ public class RenameMethodMultiTest extends MultiFileTestCase {
     doTest("pack1.A", "void staticMethod(int i)", "renamedStaticMethod");
   }
 
+  public void testRename2OverrideFinal() throws Exception {
+    try {
+      doTest("p.B", "void method()", "finalMethod");
+    }
+    catch (BaseRefactoringProcessor.ConflictsInTestsException e) {
+      Assert.assertEquals("Renaming method will override final \"method <b><code>A.finalMethod()</code></b>\"\n" +
+                          "Method finalMethod() will override\n" +
+                          "a method of the base class <b><code>p.A</code></b>.", e.getMessage());
+      return;
+    }
+    fail("Conflicts were not found");
+  }
+
   public void testAlignedMultilineParameters() throws Exception {
     getCurrentCodeStyleSettings().ALIGN_MULTILINE_PARAMETERS = true;
     getCurrentCodeStyleSettings().ALIGN_MULTILINE_PARAMETERS_IN_CALLS = true;