Do not report "accidental overrides" when "override" modifier is specified

compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/duplicateJvmSignatureUtil.kt

@@ -31,6 +31,7 @@ import org.jetbrains.jet.lang.diagnostics.Errors.*
 import org.jetbrains.jet.lang.diagnostics.DiagnosticFactory.*
 import org.jetbrains.jet.lang.psi.JetParameter
 import org.jetbrains.jet.lang.psi.JetClass
+import org.jetbrains.jet.lang.diagnostics.DiagnosticFactory
 
 public fun getJvmSignatureDiagnostics(element: PsiElement, otherDiagnostics: Diagnostics): Diagnostics? {
     fun doGetDiagnostics(): Diagnostics? {
@@ -72,7 +73,7 @@ public fun getJvmSignatureDiagnostics(element: PsiElement, otherDiagnostics: Dia
 class FilteredJvmDiagnostics(val jvmDiagnostics: Diagnostics, val otherDiagnostics: Diagnostics) : Diagnostics by jvmDiagnostics {
 
     private fun alreadyReported(psiElement: PsiElement): Boolean {
-        return otherDiagnostics.forElement(psiElement).any { it.getFactory() in setOf(CONFLICTING_OVERLOADS, REDECLARATION) }
+        return otherDiagnostics.forElement(psiElement).any { it.getFactory() in setOf<DiagnosticFactory<*>>(CONFLICTING_OVERLOADS, REDECLARATION, NOTHING_TO_OVERRIDE) }
                 || psiElement is JetPropertyAccessor && alreadyReported(psiElement.getParent()!!)
     }
 

compiler/testData/diagnostics/tests/duplicateJvmSignature/accidentalOverrides/overridesNothing.kt

@@ -0,0 +1,7 @@
+trait B {
+    fun getX() = 1
+}
+
+class C : B {
+    <!NOTHING_TO_OVERRIDE!>override<!> val x = 1
+}

compiler/testData/diagnostics/tests/override/Generics.kt

@@ -42,7 +42,7 @@ abstract class MyAbstractClass1 : MyTrait<Int>, MyAbstractClass<String>() {
 
 class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass1<!><T> : MyTrait<T>, MyAbstractClass<T>() {}
 class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalGenericClass2<!><T, R>(r : R) : MyTrait<T>, MyAbstractClass<R>() {
-    <!ACCIDENTAL_OVERRIDE!><!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R)<!> = r
+    <!NOTHING_TO_OVERRIDE!>override<!> fun foo(r: R) = r
     <!CONFLICTING_OVERLOADS!><!NOTHING_TO_OVERRIDE!>override<!> val <T> pr : R<!> = r
 }
 class <!ABSTRACT_MEMBER_NOT_IMPLEMENTED!>MyIllegalClass1<!> : MyTrait<Int>, MyAbstractClass<String>() {}

compiler/tests/org/jetbrains/jet/checkers/JetDiagnosticsTestGenerated.java

@@ -2593,6 +2593,11 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                     doTest("compiler/testData/diagnostics/tests/duplicateJvmSignature/accidentalOverrides/genericClassFunction.kt");
                 }
                 
+                @TestMetadata("overridesNothing.kt")
+                public void testOverridesNothing() throws Exception {
+                    doTest("compiler/testData/diagnostics/tests/duplicateJvmSignature/accidentalOverrides/overridesNothing.kt");
+                }
+                
                 @TestMetadata("phantomClashWithSamAdapter.kt")
                 public void testPhantomClashWithSamAdapter() throws Exception {
                     doTest("compiler/testData/diagnostics/tests/duplicateJvmSignature/accidentalOverrides/phantomClashWithSamAdapter.kt");

idea/testData/checker/OverridesAndGenerics.kt

@@ -25,7 +25,7 @@
 
     class <error>MyIllegalGenericClass1</error><T> : MyTrait<T>, MyAbstractClass<T>() {}
     class <error>MyIllegalGenericClass2</error><T, R> : MyTrait<T>, MyAbstractClass<R>() {
-        <error><error>override</error> fun foo(r: R)</error> = r
+        <error>override</error> fun foo(r: R) = r
     }
     class <error>MyIllegalClass1</error> : MyTrait<Int>, MyAbstractClass<String>() {}