push down: erase type arguments for raw subtypes (IDEA-53405)

java/java-impl/src/com/intellij/refactoring/memberPushDown/PushDownProcessor.java

@@ -334,10 +334,11 @@ public class PushDownProcessor extends BaseRefactoringProcessor {
         if (member != null) {
           for (MemberInfo memberInfo : myMemberInfos) {
             if (PsiTreeUtil.isAncestor(memberInfo.getMember(), member, false)) {
-              final PsiType substitutedType = substitutor.substitute(parameter);
-              if (substitutedType != null) {
-                element.getParent().replace(factory.createTypeElement(substitutedType));
+              PsiType substitutedType = substitutor.substitute(parameter);
+              if (substitutedType == null) {
+                substitutedType = TypeConversionUtil.erasure(factory.createType(parameter));
               }
+              element.getParent().replace(factory.createTypeElement(substitutedType));
               break;
             }
           }

java/java-tests/testData/refactoring/pushDown/TypeParameterErasure.java

@@ -0,0 +1,5 @@
+public class Parent<T> {
+  void <caret>foo(T t){}
+}
+
+class Child extends Parent {}

java/java-tests/testData/refactoring/pushDown/TypeParameterErasure.java.after

@@ -0,0 +1,6 @@
+public class Parent<T> {
+}
+
+class Child extends Parent {
+    void foo(Object t){}
+}

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

@@ -69,6 +69,10 @@ public class PushDownTest extends LightCodeInsightTestCase {
     doTest();
   }
 
+  public void testTypeParameterErasure() throws Exception {
+    doTest();
+  }
+
   public void testFieldTypeParameter() throws Exception {
     doTest();
   }