--- a/jdk/src/share/classes/javax/swing/text/AbstractDocument.java	Fri Apr 06 17:20:49 2012 +0400
+++ b/jdk/src/share/classes/javax/swing/text/AbstractDocument.java	Tue Apr 10 18:53:15 2012 +0300
@@ -31,7 +31,6 @@
 
 import javax.swing.UIManager;
 import javax.swing.undo.*;
-import javax.swing.event.ChangeListener;
 import javax.swing.event.*;
 import javax.swing.tree.TreeNode;
 
@@ -698,28 +697,31 @@
             return;
         }
         DocumentFilter filter = getDocumentFilter();
+        InsertStringResult insertStringResult = null;
 
         writeLock();
+
         try {
             if (filter != null) {
                 filter.insertString(getFilterBypass(), offs, str, a);
-            }
-            else {
-                handleInsertString(offs, str, a);
+            } else {
+                insertStringResult = handleInsertString(offs, str, a);
             }
         } finally {
             writeUnlock();
         }
+
+        processInsertStringResult(insertStringResult);
     }
 
     /**
      * Performs the actual work of inserting the text; it is assumed the
      * caller has obtained a write lock before invoking this.
      */
-    void handleInsertString(int offs, String str, AttributeSet a)
-                         throws BadLocationException {
+    private InsertStringResult handleInsertString(int offs, String str, AttributeSet a)
+            throws BadLocationException {
         if ((str == null) || (str.length() == 0)) {
-            return;
+            return null;
         }
         UndoableEdit u = data.insertString(offs, str);
         DefaultDocumentEvent e =
@@ -746,12 +748,29 @@
         insertUpdate(e, a);
         // Mark the edit as done.
         e.end();
-        fireInsertUpdate(e);
+
+        InsertStringResult result = new InsertStringResult();
+
+        result.documentEvent = e;
+
         // only fire undo if Content implementation supports it
         // undo for the composed text is not supported for now
-        if (u != null &&
-            (a == null || !a.isDefined(StyleConstants.ComposedTextAttribute))) {
-            fireUndoableEditUpdate(new UndoableEditEvent(this, e));
+        if (u != null && (a == null || !a.isDefined(StyleConstants.ComposedTextAttribute))) {
+            result.undoableEditEvent = new UndoableEditEvent(this, e);
+        }
+
+        return result;
+    }
+
+    private void processInsertStringResult(InsertStringResult insertStringResult) {
+        if (insertStringResult == null) {
+            return;
+        }
+
+        fireInsertUpdate(insertStringResult.documentEvent);
+
+        if (insertStringResult.undoableEditEvent != null) {
+            fireUndoableEditUpdate(insertStringResult.undoableEditEvent);
         }
     }
 
@@ -2947,12 +2966,10 @@
      */
     class UndoRedoDocumentEvent implements DocumentEvent {
         private DefaultDocumentEvent src = null;
-        private boolean isUndo;
         private EventType type = null;
 
         public UndoRedoDocumentEvent(DefaultDocumentEvent src, boolean isUndo) {
             this.src = src;
-            this.isUndo = isUndo;
             if(isUndo) {
                 if(src.getType().equals(EventType.INSERT)) {
                     type = EventType.REMOVE;
@@ -3106,13 +3123,23 @@
         public void insertString(int offset, String string,
                                  AttributeSet attr) throws
                                         BadLocationException {
-            handleInsertString(offset, string, attr);
+            InsertStringResult insertStringResult = handleInsertString(offset, string, attr);
+
+            processInsertStringResult(insertStringResult);
         }
 
         public void replace(int offset, int length, String text,
                             AttributeSet attrs) throws BadLocationException {
             handleRemove(offset, length);
-            handleInsertString(offset, text, attrs);
+
+            InsertStringResult insertStringResult = handleInsertString(offset, text, attrs);
+
+            processInsertStringResult(insertStringResult);
         }
     }
+
+    private static class InsertStringResult {
+        DefaultDocumentEvent documentEvent;
+        UndoableEditEvent undoableEditEvent;
+    }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/swing/text/AbstractDocument/7146146/bug7146146.java	Tue Apr 10 18:53:15 2012 +0300
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2012, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/* @test
+   @bug 7146146
+   @summary Deadlock between subclass of AbstractDocument and UndoManager
+   @author Pavel Porvatov
+*/
+
+import javax.swing.text.BadLocationException;
+import javax.swing.text.PlainDocument;
+import javax.swing.text.StringContent;
+import javax.swing.undo.UndoManager;
+
+public class bug7146146 {
+    public static void main(String[] args) throws Exception {
+        for (int i = 0; i < 1000; i++) {
+            System.out.print("Iteration " + i);
+
+            test();
+
+            System.out.print(" passed");
+        }
+    }
+
+    private static void test() throws Exception {
+        final PlainDocument doc = new PlainDocument(new StringContent());
+        final UndoManager undoManager = new UndoManager();
+
+        doc.addUndoableEditListener(undoManager);
+        doc.insertString(0, "<Test 1>", null);
+
+        Thread t1 = new Thread("Thread 1") {
+            @Override
+            public void run() {
+                try {
+                    doc.insertString(0, "<Test 2>", null);
+                } catch (BadLocationException e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        };
+
+        Thread t2 = new Thread("Thread 2") {
+            @Override
+            public void run() {
+                undoManager.undo();
+            }
+        };
+
+        t1.start();
+        t2.start();
+
+        t1.join();
+        t2.join();
+    }
+}