manage DummyHolder's tree in the same way as PsiFileImpl does (EA-96901 - assert: FileTrees.withGreenStub)

java/java-tests/testSrc/com/intellij/codeInspection/PurityInferenceFromSourceTest.groovy

@@ -213,6 +213,24 @@ public Foo() {
     """
   }
 
+  void "test delegate to a method calling local class constructor"() {
+    myFixture.addClass("""
+class Another { 
+  static Object method() {
+    class LocalClass {
+      LocalClass() { launchMissiles(); }
+    }
+    return new LocalClass();
+  } 
+}
+  """)
+    assertPure false, """
+    Object smth() {
+        return Another.method();
+    }
+    """
+  }
+
   private void assertPure(boolean expected, String classBody) {
     def clazz = myFixture.addClass("final class Foo { $classBody }")
     assert !((PsiFileImpl) clazz.containingFile).contentsLoaded

java/java-tests/testSrc/com/intellij/psi/StubAstSwitchTest.groovy

@@ -20,6 +20,8 @@ import com.intellij.openapi.application.ReadAction
 import com.intellij.openapi.command.WriteCommandAction
 import com.intellij.openapi.fileEditor.FileDocumentManager
 import com.intellij.openapi.vfs.VfsUtil
+import com.intellij.psi.impl.java.stubs.JavaStubElementTypes
+import com.intellij.psi.impl.source.DummyHolder
 import com.intellij.psi.impl.source.PsiClassImpl
 import com.intellij.psi.impl.source.PsiFileImpl
 import com.intellij.psi.impl.source.PsiJavaFileImpl
@@ -317,4 +319,14 @@ class B {
       }
     }
   }
+
+  void "test DummyHolder calcStubTree does not fail"() {
+    def text = "{ new Runnable() { public void run() {} }; }"
+    def file = JavaPsiFacade.getElementFactory(project).createCodeBlockFromText(text, null).containingFile
+
+    // main thing is it doesn't fail; DummyHolder.calcStubTree can be changed to null in future if we decide we don't need it
+    def stubTree = assertInstanceOf(file, DummyHolder).calcStubTree()
+
+    assert stubTree.plainList.find { it.stubType == JavaStubElementTypes.ANONYMOUS_CLASS }
+  }
 }