extract method: use target class context to check nullability

java/java-impl/src/com/intellij/refactoring/extractMethod/ExtractMethodProcessor.java

@@ -630,7 +630,7 @@ public class ExtractMethodProcessor implements MatchProvider {
 
   private Nullness initNullness() {
     if (!PsiUtil.isLanguageLevel5OrHigher(myElements[0]) || PsiUtil.resolveClassInType(myReturnType) == null) return null;
-    final PsiMethod emptyMethod = generateEmptyMethod(getThrownExceptions(), isStatic(), "name");
+    final PsiMethod emptyMethod = (PsiMethod)myTargetClass.copy().add(generateEmptyMethod(getThrownExceptions(), isStatic(), "name"));
     prepareMethodBody(emptyMethod, false);
     final NullableNotNullManager manager = NullableNotNullManager.getInstance(myProject);
     final PsiClass nullableAnnotationClass = JavaPsiFacade.getInstance(myProject)

java/java-tests/testData/refactoring/extractMethod/InferredNotNull.java

@@ -0,0 +1,14 @@
+import org.jetbrains.annotations.NotNull;
+
+class X {
+  public static String main(String[] args) {
+    <selection>System.out.println();
+    return f();
+    </selection>
+  }
+
+  @NotNull
+  String f() {
+    return "";
+  }
+}

java/java-tests/testData/refactoring/extractMethod/InferredNotNull_after.java

@@ -0,0 +1,19 @@
+import org.jetbrains.annotations.NotNull;
+
+class X {
+  public static String main(String[] args) {
+      return newMethod();
+    
+  }
+
+    @NotNull
+    private static String newMethod() {
+        System.out.println();
+        return f();
+    }
+
+    @NotNull
+  String f() {
+    return "";
+  }
+}

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

@@ -698,6 +698,10 @@ public class ExtractMethodTest extends LightCodeInsightTestCase {
     }
   }
 
+  public void testInferredNotNull() throws Exception {
+    doTest();
+  }
+
   public void testCantPassFieldAsParameter() throws Exception {
     try {
       doTestPassFieldsAsParams();