From b5fc4155da83f7086bd567b1d13251bc3b748a92 Mon Sep 17 00:00:00 2001
From: Dmitry Batrak <Dmitry.Batrak@jetbrains.com>
Date: Thu, 10 Sep 2015 20:06:19 +0300
Subject: [PATCH] EA-72909 - ISE:
 DocumentUndoProvider$MyEditorDocumentListener.beforeDocumentChange

---
 .../intellij/util/FileContentUtilCore.java    |  4 ++--
 .../psi/impl/PsiDocumentManagerImplTest.java  | 21 +++++++++++++++++++
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/platform/core-api/src/com/intellij/util/FileContentUtilCore.java b/platform/core-api/src/com/intellij/util/FileContentUtilCore.java
index 387407c21874..c7c9586ccb0d 100644
--- a/platform/core-api/src/com/intellij/util/FileContentUtilCore.java
+++ b/platform/core-api/src/com/intellij/util/FileContentUtilCore.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -78,7 +78,7 @@ public class FileContentUtilCore {
     if (documentManager.isFileModified(file)) {
       Document document = documentManager.getDocument(file);
       if (document != null) {
-        documentManager.saveDocument(document);
+        documentManager.saveDocumentAsIs(document); // this can be called e.g. in context of undo, so we shouldn't modify document
       }
     }
 
diff --git a/platform/platform-tests/testSrc/com/intellij/psi/impl/PsiDocumentManagerImplTest.java b/platform/platform-tests/testSrc/com/intellij/psi/impl/PsiDocumentManagerImplTest.java
index 647a7f2fe29d..893ab3485879 100644
--- a/platform/platform-tests/testSrc/com/intellij/psi/impl/PsiDocumentManagerImplTest.java
+++ b/platform/platform-tests/testSrc/com/intellij/psi/impl/PsiDocumentManagerImplTest.java
@@ -25,7 +25,9 @@ import com.intellij.openapi.application.ModalityState;
 import com.intellij.openapi.application.impl.LaterInvocator;
 import com.intellij.openapi.command.WriteCommandAction;
 import com.intellij.openapi.editor.Document;
+import com.intellij.openapi.editor.ex.EditorSettingsExternalizable;
 import com.intellij.openapi.editor.impl.DocumentImpl;
+import com.intellij.openapi.editor.impl.TrailingSpacesStripper;
 import com.intellij.openapi.editor.impl.event.DocumentEventImpl;
 import com.intellij.openapi.fileEditor.FileDocumentManager;
 import com.intellij.openapi.project.Project;
@@ -36,6 +38,7 @@ import com.intellij.openapi.util.io.FileUtilRt;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.LocalFileSystem;
 import com.intellij.openapi.vfs.VfsUtil;
+import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.*;
 import com.intellij.psi.impl.source.PsiFileImpl;
@@ -51,6 +54,8 @@ import org.jetbrains.annotations.Nullable;
 import javax.swing.*;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.Charset;
+import java.util.Collections;
 import java.util.concurrent.atomic.AtomicInteger;
 
 public class PsiDocumentManagerImplTest extends PlatformTestCase {
@@ -559,4 +564,20 @@ public class PsiDocumentManagerImplTest extends PlatformTestCase {
     assertTrue(getPsiDocumentManager().isCommitted(document));
     LaterInvocator.leaveModal(dialog);
   }
+  
+  public void testReparseDoesNotModifyDocument() throws Exception {
+    VirtualFile file = createTempFile("txt", null, "foo", Charset.forName("UTF-8"));
+    file.putUserData(TrailingSpacesStripper.OVERRIDE_STRIP_TRAILING_SPACES_KEY, EditorSettingsExternalizable.STRIP_TRAILING_SPACES_WHOLE);
+    final Document document = FileDocumentManager.getInstance().getDocument(file);
+    assertNotNull(document);
+    WriteCommandAction.runWriteCommandAction(myProject, new Runnable() {
+      @Override
+      public void run() {
+        document.insertString(3, " ");
+      }
+    });
+    
+    PsiDocumentManager.getInstance(myProject).reparseFiles(Collections.singleton(file), false);
+    assertEquals("foo ", VfsUtilCore.loadText(file));
+  }
 }