From d85a101ade90f63f82f902e33426611db512f76f Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 2 Apr 2012 20:13:55 +0200
Subject: [PATCH] nullify stub->psi reference when stub-based file is changed,
 simpler isValid check for stub elements

---
 .../extapi/psi/StubBasedPsiElementBase.java   |  7 ++----
 .../intellij/psi/impl/source/PsiFileImpl.java | 25 ++++++++-----------
 2 files changed, 13 insertions(+), 19 deletions(-)

diff --git a/platform/core-impl/src/com/intellij/extapi/psi/StubBasedPsiElementBase.java b/platform/core-impl/src/com/intellij/extapi/psi/StubBasedPsiElementBase.java
index 1477e2344d70..094d56c5a024 100644
--- a/platform/core-impl/src/com/intellij/extapi/psi/StubBasedPsiElementBase.java
+++ b/platform/core-impl/src/com/intellij/extapi/psi/StubBasedPsiElementBase.java
@@ -154,11 +154,8 @@ public class StubBasedPsiElementBase<T extends StubElement> extends ASTDelegateP
   public boolean isValid() {
     T stub = myStub;
     if (stub != null) {
-      PsiElement parentPsi = stub.getParentStub().getPsi();
-      if (parentPsi instanceof PsiFileImpl) {
-        return ((PsiFileImpl) parentPsi).isStubBasedChildValid(this);
-      }
-      return parentPsi.isValid();
+      PsiElement psi = stub.getParentStub().getPsi();
+      return psi != null && psi.isValid();
     }
 
     return super.isValid();
diff --git a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
index ef0e78c11bf1..c7f29a62d3f5 100644
--- a/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
+++ b/platform/core-impl/src/com/intellij/psi/impl/source/PsiFileImpl.java
@@ -220,7 +220,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
         stubs.next(); // Skip file stub;
         switchFromStubToAST(treeElement, stubs);
 
-        myStub = null;
+        clearStub();
       }
 
       setTreeElement(treeElement);
@@ -249,17 +249,6 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
     return findTreeForStub(ast, stubs, stub);
   }
 
-  public boolean isStubBasedChildValid(@NotNull StubBasedPsiElementBase child) {
-    synchronized (myStubLock) {
-      StubTree fileStub = derefStub();
-      StubElement childStub = child.getStub();
-      if (childStub != null && (fileStub == null || fileStub.getRoot() != childStub.getParentStub())) {
-        return false;
-      }
-    }
-    return isValid();
-  }
-
   @Nullable
   private static ASTNode findTreeForStub(ASTNode tree, final Iterator<StubElement<?>> stubs, final StubElement stub) {
     final IElementType type = tree.getElementType();
@@ -352,10 +341,18 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
     myViewProvider.beforeContentsSynchronized();
     setTreeElement(null);
     synchronized (myStubLock) {
-      myStub = null;
+      clearStub();
     }
   }
 
+  private void clearStub() {
+    StubTree stubHolder = myStub == null ? null : myStub.get();
+    if (stubHolder != null) {
+      ((StubBase<?>)stubHolder.getRoot()).setPsi(null);
+    }
+    myStub = null;
+  }
+
   public void clearCaches() {}
 
   @Override
@@ -404,7 +401,7 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
     }
 
     synchronized (myStubLock) {
-      myStub = null;
+      clearStub();
       if (tree != null) {
         tree.putUserData(STUB_TREE_IN_PARSED_TREE, null);
       }