From 4613badeb362d1d1fcd41225dec8506258cb12c2 Mon Sep 17 00:00:00 2001
From: Eugene Zhuravlev <jeka@intellij.com>
Date: Fri, 29 Nov 2013 15:31:01 +0100
Subject: [PATCH] fix NPEs

---
 .../debugger/engine/DebugProcessImpl.java        | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/java/debugger/impl/src/com/intellij/debugger/engine/DebugProcessImpl.java b/java/debugger/impl/src/com/intellij/debugger/engine/DebugProcessImpl.java
index dc9d1e9e1ec7..a5b1be2ba733 100644
--- a/java/debugger/impl/src/com/intellij/debugger/engine/DebugProcessImpl.java
+++ b/java/debugger/impl/src/com/intellij/debugger/engine/DebugProcessImpl.java
@@ -99,7 +99,7 @@ public abstract class DebugProcessImpl implements DebugProcess {
   private final Project myProject;
   private final RequestManagerImpl myRequestManager;
 
-  private VirtualMachineProxyImpl myVirtualMachineProxy = null;
+  private volatile VirtualMachineProxyImpl myVirtualMachineProxy = null;
   protected EventDispatcher<DebugProcessListener> myDebugProcessDispatcher = EventDispatcher.create(DebugProcessListener.class);
   protected EventDispatcher<EvaluationListener> myEvaluationDispatcher = EventDispatcher.create(EvaluationListener.class);
 
@@ -685,11 +685,13 @@ public abstract class DebugProcessImpl implements DebugProcess {
   }
 
   public boolean canRedefineClasses() {
-    return myVirtualMachineProxy != null && myVirtualMachineProxy.canRedefineClasses();
+    final VirtualMachineProxyImpl vm = myVirtualMachineProxy;
+    return vm != null && vm.canRedefineClasses();
   }
 
   public boolean canWatchFieldModification() {
-    return myVirtualMachineProxy != null && myVirtualMachineProxy.canWatchFieldModification();
+    final VirtualMachineProxyImpl vm = myVirtualMachineProxy;
+    return vm != null && vm.canWatchFieldModification();
   }
 
   public boolean isInInitialState() {
@@ -714,10 +716,11 @@ public abstract class DebugProcessImpl implements DebugProcess {
 
   public VirtualMachineProxyImpl getVirtualMachineProxy() {
     DebuggerManagerThreadImpl.assertIsManagerThread();
-    if (myVirtualMachineProxy == null) {
+    final VirtualMachineProxyImpl vm = myVirtualMachineProxy;
+    if (vm == null) {
       throw new VMDisconnectedException();
     }
-    return myVirtualMachineProxy;
+    return vm;
   }
 
   public void appendPositionManager(final PositionManager positionManager) {
@@ -1820,7 +1823,8 @@ public abstract class DebugProcessImpl implements DebugProcess {
   }
 
   public boolean isPausePressed() {
-    return myVirtualMachineProxy != null && myVirtualMachineProxy.isPausePressed();
+    final VirtualMachineProxyImpl vm = myVirtualMachineProxy;
+    return vm != null && vm.isPausePressed();
   }
 
   public DebuggerCommandImpl createPauseCommand() {