From 44a8ce13bd243efd3e4a7844ec5c8ada652ae179 Mon Sep 17 00:00:00 2001
From: "Maxim.Mossienko" <Maxim.Mossienko@jetbrains.com>
Date: Fri, 18 Nov 2016 17:50:23 +0100
Subject: [PATCH] access to indices after disposal doesn't lead to NPE
 (IDEA-164170)

---
 .../src/com/intellij/util/indexing/MapReduceIndex.java       | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java b/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java
index 44a53d3375be..186897bf1aeb 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/MapReduceIndex.java
@@ -74,6 +74,7 @@ public class MapReduceIndex<Key, Value, Input> implements UpdatableIndex<Key,Val
   private PersistentHashMap<Integer, Integer> myInputsSnapshotMapping;
   @Nullable protected PersistentHashMap<Integer, Collection<Key>> myInputsIndex;
   private PersistentHashMap<Integer, String> myIndexingTrace;
+  private volatile boolean myDisposed;
 
   private final ReentrantReadWriteLock myLock = new ReentrantReadWriteLock();
 
@@ -329,6 +330,7 @@ public class MapReduceIndex<Key, Value, Input> implements UpdatableIndex<Key,Val
       LOG.error(e);
     }
     finally {
+      myDisposed = true;
       lock.unlock();
     }
   }
@@ -389,6 +391,9 @@ public class MapReduceIndex<Key, Value, Input> implements UpdatableIndex<Key,Val
     final Lock lock = getReadLock();
     try {
       lock.lock();
+      if (myDisposed) {
+        return new ValueContainerImpl<>();
+      }
       ValueContainerImpl.ourDebugIndexInfo.set(myIndexId);
       return myStorage.read(key);
     }