From 2c2f8b97c9abbebb15fdde2c796a8bd09595dc5c Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 25 Jun 2018 18:55:52 +0200
Subject: [PATCH] don't record undo for free-threaded document changes
 (EA-123049 - REWA: DocumentReferenceManagerImpl.create)

---
 .../com/intellij/openapi/command/impl/DocumentUndoProvider.java | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/platform/platform-impl/src/com/intellij/openapi/command/impl/DocumentUndoProvider.java b/platform/platform-impl/src/com/intellij/openapi/command/impl/DocumentUndoProvider.java
index 7a6cc7018ebe..eec0d6328a3d 100644
--- a/platform/platform-impl/src/com/intellij/openapi/command/impl/DocumentUndoProvider.java
+++ b/platform/platform-impl/src/com/intellij/openapi/command/impl/DocumentUndoProvider.java
@@ -16,6 +16,7 @@
 package com.intellij.openapi.command.impl;
 
 import com.intellij.openapi.Disposable;
+import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.command.undo.DocumentReference;
 import com.intellij.openapi.command.undo.DocumentReferenceManager;
 import com.intellij.openapi.command.undo.UndoConstants;
@@ -88,6 +89,7 @@ public class DocumentUndoProvider implements Disposable {
     
     private boolean shouldProcess(Document document) {
       if (myProject != null && myProject.isDisposed()) return false;
+      if (!ApplicationManager.getApplication().isDispatchThread()) return false; // some light document
       return !UndoManagerImpl.isCopy(document) // if we don't ignore copy's events, we will receive notification
              // for the same event twice (from original document too)
              // and undo will work incorrectly