From d94d0f404f2791f64b005a0b6a257333cfc64ba2 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Thu, 24 Sep 2015 17:43:34 +0200
Subject: [PATCH] PsiFileImpl: fix race condition between AST and stub loading,
 which resulted in stub elements being not bound to AST

---
 .../intellij/psi/impl/source/PsiFileImpl.java | 21 +++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

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 d36d802a8008..93faaab938dd 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
@@ -186,15 +186,32 @@ public abstract class PsiFileImpl extends ElementBase implements PsiFileEx, PsiF
     FileElement treeElement = createFileElement(viewProvider.getContents());
     treeElement.setPsi(this);
 
-    final StubTree stub = derefStub();
-    List<Pair<StubBasedPsiElementBase, CompositeElement>> bindings = calcStubAstBindings(treeElement, cachedDocument, stub);
+    while (true) {
+      StubTree stub = derefStub();
+      List<Pair<StubBasedPsiElementBase, CompositeElement>> bindings = calcStubAstBindings(treeElement, cachedDocument, stub);
 
+      FileElement savedTree = ensureTreeElement(viewProvider, treeElement, stub, bindings);
+      if (savedTree != null) {
+        return savedTree;
+      }
+    }
+  }
+
+  @Nullable
+  private FileElement ensureTreeElement(@NotNull FileViewProvider viewProvider,
+                                        @NotNull FileElement treeElement,
+                                        @Nullable StubTree stub,
+                                        @NotNull List<Pair<StubBasedPsiElementBase, CompositeElement>> bindings) {
     synchronized (PsiLock.LOCK) {
       FileElement existing = derefTreeElement();
       if (existing != null) {
         return existing;
       }
 
+      if (stub != derefStub()) {
+        return null; // stub has been just loaded by another thread, it needs to be bound to AST
+      }
+
       if (stub != null) {
         treeElement.putUserData(STUB_TREE_IN_PARSED_TREE, new SoftReference<StubTree>(stub));
         putUserData(ObjectStubTree.LAST_STUB_TREE_HASH, stub.hashCode());