Change Signature: Fix replacement of implicit Unit return type

idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/usages/KotlinCallableDefinitionUsage.kt

@@ -148,12 +148,7 @@ class KotlinCallableDefinitionUsage<T : PsiElement>(
         if (element !is KtCallableDeclaration) return
         if (element is KtConstructor<*>) return
 
-        val returnTypeIsNeeded = if (element is KtFunction) {
-            element !is KtFunctionLiteral && (changeInfo.isRefactoringTarget(originalCallableDescriptor) || element.typeReference != null)
-        }
-        else {
-            element is KtProperty || element is KtParameter
-        }
+        val returnTypeIsNeeded = (element is KtFunction && element !is KtFunctionLiteral) || element is KtProperty || element is KtParameter
 
         if (changeInfo.isReturnTypeChanged && returnTypeIsNeeded) {
             element.typeReference = null

idea/testData/refactoring/changeSignature/ChangeReturnTypeToNonUnitAfter.kt

@@ -0,0 +1,11 @@
+open class A {
+    open fun foo(): Int {
+
+    }
+}
+
+class B : A() {
+    override fun foo(): Int {
+
+    }
+}

idea/testData/refactoring/changeSignature/ChangeReturnTypeToNonUnitBefore.kt

@@ -0,0 +1,11 @@
+open class A {
+    open fun <caret>foo() {
+
+    }
+}
+
+class B : A() {
+    override fun foo() {
+
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt

@@ -956,4 +956,8 @@ class KotlinChangeSignatureTest : KotlinLightCodeInsightFixtureTestCase() {
         newName = "bar"
         newReturnTypeInfo = resolveType("A<T, U>", true, true)
     }
+
+    fun testChangeReturnTypeToNonUnit() = doTest {
+        newReturnTypeInfo = KotlinTypeInfo(true, BUILT_INS.intType)
+    }
 }