change signature: remove @Override if only overrider was changed (IDEA-154669)

java/java-impl/src/com/intellij/refactoring/changeSignature/JavaChangeSignatureUsageProcessor.java

@@ -770,6 +770,13 @@ public class JavaChangeSignatureUsageProcessor implements ChangeSignatureUsagePr
       final PsiClassType[] newExceptions = getPrimaryChangedExceptionInfo(changeInfo);
       fixPrimaryThrowsLists(method, newExceptions);
     }
+
+    if (baseMethod == null && method.findSuperMethods().length == 0) {
+      final PsiAnnotation annotation = AnnotationUtil.findAnnotation(method, true, Override.class.getName());
+      if (annotation != null) {
+        annotation.delete();
+      }
+    }
   }
 
   private static int processMethodParams(JavaChangeInfo changeInfo,

java/java-tests/testData/refactoring/changeSignature/PreserveOverride.java

@@ -0,0 +1,7 @@
+class A {
+  public void <caret>foo(int i) {}
+}
+class Test extends A {
+  @Override
+  public void foo(int i) {}
+}

java/java-tests/testData/refactoring/changeSignature/PreserveOverride_after.java

@@ -0,0 +1,7 @@
+class A {
+  public void <caret>foo() {}
+}
+class Test extends A {
+  @Override
+  public void foo() {}
+}

java/java-tests/testData/refactoring/changeSignature/RemoveOverride.java

@@ -0,0 +1,7 @@
+class A {
+  public void foo(int i) {}
+}
+class Test extends A {
+  @Override
+  public void <caret>foo(int i) {}
+}

java/java-tests/testData/refactoring/changeSignature/RemoveOverride_after.java

@@ -0,0 +1,6 @@
+class A {
+  public void foo(int i) {}
+}
+class Test extends A {
+  public void <caret>foo() {}
+}

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

@@ -376,6 +376,14 @@ public class ChangeSignatureTest extends ChangeSignatureBaseTest {
     doTest(null, null, "Exception", new SimpleParameterGen(), new SimpleExceptionsGen(), false);
   }
 
+  public void testRemoveOverride() {
+    doTest(null, null, null, new ParameterInfoImpl[0], new ThrownExceptionInfo[0], false);
+  }
+
+  public void testPreserveOverride() {
+    doTest(null, null, null, new ParameterInfoImpl[0], new ThrownExceptionInfo[0], false);
+  }
+
   public void testVisibilityOfOverriddenMethod() {
     doTest(PsiModifier.PACKAGE_LOCAL, "foo", "void", new ParameterInfoImpl[0], new ThrownExceptionInfo[0], false);
   }