let psi file become invalid when its original file is invalid

because otherwise clients call getOriginalFile and end up with invalid PSI

java/java-tests/testSrc/com/intellij/java/psi/ClsPsiTest.java

@@ -16,6 +16,7 @@
 package com.intellij.java.psi;
 
 import com.intellij.lang.java.JavaLanguage;
+import com.intellij.openapi.application.WriteAction;
 import com.intellij.openapi.application.ex.PathManagerEx;
 import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.openapi.util.io.IoTestUtil;
@@ -461,4 +462,23 @@ public class ClsPsiTest extends LightIdeaTestCase {
     LeakHunter.checkLeak(dbl, ClassElement.class, element -> element.getPsi().getUserData(ClsElementImpl.COMPILED_ELEMENT) == dbl);
     assertFalse(hash1 == ((ClsClassImpl)dbl).getMirror().hashCode());
   }
+
+  public void testMirrorBecomesInvalidTogetherWithCls() throws IOException {
+    File testFile = IoTestUtil.createTestFile("TestClass.class");
+    File file1 = new File(PathManagerEx.getTestDataPath() + TEST_DATA_PATH + "/1_TestClass.class");
+    FileUtil.copy(file1, testFile);
+    VirtualFile copyVFile = LocalFileSystem.getInstance().refreshAndFindFileByIoFile(testFile);
+    
+    ClsFileImpl clsFile = (ClsFileImpl)PsiManager.getInstance(getProject()).findFile(copyVFile);
+    PsiElement mirror = clsFile.getMirror();
+
+    assertTrue(clsFile.isValid());
+    assertTrue(mirror.isValid());
+
+    WriteAction.run(() -> copyVFile.delete(this));
+    assertFalse(clsFile.isValid());
+    assertFalse(mirror.isValid());
+    assertTrue(PsiInvalidElementAccessException.findOutInvalidationReason(mirror)
+                 .contains(PsiInvalidElementAccessException.findOutInvalidationReason(clsFile)));
+  }
 }

platform/core-api/src/com/intellij/psi/PsiInvalidElementAccessException.java

@@ -107,7 +107,12 @@ public class PsiInvalidElementAccessException extends RuntimeException implement
   @Nullable
   private static Object getPsiInvalidationTrace(@NotNull PsiElement element) {
     Object trace = getInvalidationTrace(element);
-    return trace != null || element instanceof PsiFile ? trace : findInvalidationTrace(element.getNode());
+    if (trace != null) return trace;
+    
+    if (element instanceof PsiFile) {
+      return getInvalidationTrace(((PsiFile)element).getOriginalFile());
+    }
+    return findInvalidationTrace(element.getNode());
   }
 
   private static String getMessageWithReason(@NotNull PsiElement element,
@@ -120,7 +125,7 @@ public class PsiInvalidElementAccessException extends RuntimeException implement
                          trace != null ? "see attachment" :
                          "no info";
       try {
-        reason += " because: " + reason(element);
+        reason += " because: " + findOutInvalidationReason(element);
       }
       catch (PsiInvalidElementAccessException ignore) {
       }
@@ -161,7 +166,7 @@ public class PsiInvalidElementAccessException extends RuntimeException implement
 
   @NonNls
   @NotNull
-  private static String reason(@NotNull PsiElement root) {
+  public static String findOutInvalidationReason(@NotNull PsiElement root) {
     if (root == PsiUtilCore.NULL_PSI_ELEMENT) return "NULL_PSI_ELEMENT";
 
     PsiElement element = root instanceof PsiFile ? root : root.getParent();
@@ -170,6 +175,7 @@ public class PsiInvalidElementAccessException extends RuntimeException implement
       if (root instanceof StubBasedPsiElement) {
         StubElement stub = ((StubBasedPsiElement)root).getStub();
         while (stub != null) {
+          //noinspection StringConcatenationInLoop
           m += "\n  each stub=" + stub;
           if (stub instanceof PsiFileStub) {
             m += "; fileStub.psi=" + stub.getPsi() + "; reason=" + ((PsiFileStub)stub).getInvalidationReason();
@@ -190,10 +196,15 @@ public class PsiInvalidElementAccessException extends RuntimeException implement
     if (!provider.isPhysical()) {
       PsiElement context = file.getContext();
       if (context != null && !context.isValid()) {
-        return "invalid context: " + reason(context);
+        return "invalid context: " + findOutInvalidationReason(context);
       }
     }
 
+    PsiFile original = file.getOriginalFile();
+    if (original != file && !original.isValid()) {
+      return "invalid original: " + findOutInvalidationReason(original);
+    }
+
     PsiManager manager = file.getManager();
     if (manager.getProject().isDisposed()) return "project is disposed";
 

platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java

@@ -162,6 +162,9 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
       // but some VFS listeners receive the same events before that and ask PsiFile.isValid
       return false;
     }
+    if (myOriginalFile != null && !myOriginalFile.isValid()) {
+      return false;
+    }
     return !myInvalidated;
   }