--- a/jdk/src/share/classes/javax/swing/text/html/HTMLEditorKit.java	Fri Jun 18 13:18:42 2010 +0400
+++ b/jdk/src/share/classes/javax/swing/text/html/HTMLEditorKit.java	Mon Jun 21 16:47:05 2010 +0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2010, 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
@@ -24,6 +24,8 @@
  */
 package javax.swing.text.html;
 
+import sun.awt.AppContext;
+
 import java.lang.reflect.Method;
 import java.awt.*;
 import java.awt.event.*;
@@ -369,7 +371,11 @@
      * if desired.
      */
     public void setStyleSheet(StyleSheet s) {
-        defaultStyles = s;
+        if (s == null) {
+            AppContext.getAppContext().remove(DEFAULT_STYLES_KEY);
+        } else {
+            AppContext.getAppContext().put(DEFAULT_STYLES_KEY, s);
+        }
     }
 
     /**
@@ -379,8 +385,12 @@
      * instances.
      */
     public StyleSheet getStyleSheet() {
+        AppContext appContext = AppContext.getAppContext();
+        StyleSheet defaultStyles = (StyleSheet) appContext.get(DEFAULT_STYLES_KEY);
+
         if (defaultStyles == null) {
             defaultStyles = new StyleSheet();
+            appContext.put(DEFAULT_STYLES_KEY, defaultStyles);
             try {
                 InputStream is = HTMLEditorKit.getResourceAsStream(DEFAULT_CSS);
                 Reader r = new BufferedReader(
@@ -620,7 +630,7 @@
     private static final ViewFactory defaultFactory = new HTMLFactory();
 
     MutableAttributeSet input;
-    private static StyleSheet defaultStyles = null;
+    private static final Object DEFAULT_STYLES_KEY = new Object();
     private LinkController linkHandler = new LinkController();
     private static Parser defaultParser = null;
     private Cursor defaultCursor = DefaultCursor;

--- a/jdk/src/share/classes/javax/swing/text/html/parser/DTD.java	Fri Jun 18 13:18:42 2010 +0400
+++ b/jdk/src/share/classes/javax/swing/text/html/parser/DTD.java	Mon Jun 21 16:47:05 2010 +0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2008, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2010, 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
@@ -25,6 +25,8 @@
 
 package javax.swing.text.html.parser;
 
+import sun.awt.AppContext;
+
 import java.io.PrintStream;
 import java.io.File;
 import java.io.FileInputStream;
@@ -314,13 +316,14 @@
     }
 
     /**
-     * The hashtable of DTDs.
+     * The hashtable key of DTDs in AppContext.
      */
-    static Hashtable<String, DTD> dtdHash = new Hashtable<String, DTD>();
+    private static final Object DTD_HASH_KEY = new Object();
 
-  public static void putDTDHash(String name, DTD dtd) {
-    dtdHash.put(name, dtd);
-  }
+    public static void putDTDHash(String name, DTD dtd) {
+        getDtdHash().put(name, dtd);
+    }
+
     /**
      * Returns a DTD with the specified <code>name</code>.  If
      * a DTD with that name doesn't exist, one is created
@@ -332,13 +335,27 @@
      */
     public static DTD getDTD(String name) throws IOException {
         name = name.toLowerCase();
-        DTD dtd = dtdHash.get(name);
+        DTD dtd = getDtdHash().get(name);
         if (dtd == null)
           dtd = new DTD(name);
 
         return dtd;
     }
 
+    private static Hashtable<String, DTD> getDtdHash() {
+        AppContext appContext = AppContext.getAppContext();
+
+        Hashtable<String, DTD> result = (Hashtable<String, DTD>) appContext.get(DTD_HASH_KEY);
+
+        if (result == null) {
+            result = new Hashtable<String, DTD>();
+
+            appContext.put(DTD_HASH_KEY, result);
+        }
+
+        return result;
+    }
+
     /**
      * Recreates a DTD from an archived format.
      * @param in  the <code>DataInputStream</code> to read from

--- a/jdk/src/share/classes/javax/swing/text/html/parser/ParserDelegator.java	Fri Jun 18 13:18:42 2010 +0400
+++ b/jdk/src/share/classes/javax/swing/text/html/parser/ParserDelegator.java	Mon Jun 21 16:47:05 2010 +0400
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2002, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2010, 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
@@ -25,6 +25,8 @@
 
 package javax.swing.text.html.parser;
 
+import sun.awt.AppContext;
+
 import javax.swing.text.html.HTMLEditorKit;
 import java.io.BufferedInputStream;
 import java.io.IOException;
@@ -33,7 +35,6 @@
 import java.io.ObjectInputStream;
 import java.io.Reader;
 import java.io.Serializable;
-import java.lang.reflect.Method;
 
 /**
  * Responsible for starting up a new DocumentParser
@@ -45,9 +46,13 @@
 
 public class ParserDelegator extends HTMLEditorKit.Parser implements Serializable {
 
-    private static DTD dtd = null;
+    private static final Object DTD_KEY = new Object();
 
     protected static synchronized void setDefaultDTD() {
+        AppContext appContext = AppContext.getAppContext();
+
+        DTD dtd = (DTD) appContext.get(DTD_KEY);
+
         if (dtd == null) {
             DTD _dtd = null;
             // (PENDING) Hate having to hard code!
@@ -59,6 +64,8 @@
                 System.out.println("Throw an exception: could not get default dtd: " + nm);
             }
             dtd = createDTD(_dtd, nm);
+
+            appContext.put(DTD_KEY, dtd);
         }
     }
 
@@ -81,13 +88,11 @@
 
 
     public ParserDelegator() {
-        if (dtd == null) {
-            setDefaultDTD();
-        }
+        setDefaultDTD();
     }
 
     public void parse(Reader r, HTMLEditorKit.ParserCallback cb, boolean ignoreCharSet) throws IOException {
-        new DocumentParser(dtd).parse(r, cb, ignoreCharSet);
+        new DocumentParser((DTD) AppContext.getAppContext().get(DTD_KEY)).parse(r, cb, ignoreCharSet);
     }
 
     /**
@@ -113,8 +118,6 @@
     private void readObject(ObjectInputStream s)
         throws ClassNotFoundException, IOException {
         s.defaultReadObject();
-        if (dtd == null) {
-            setDefaultDTD();
-        }
+        setDefaultDTD();
     }
 }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/swing/Security/6938813/bug6938813.java	Mon Jun 21 16:47:05 2010 +0400
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2010, 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 6938813
+ * @summary Swing mutable statics
+ * @author Pavel Porvatov
+ */
+
+import sun.awt.AppContext;
+import sun.awt.SunToolkit;
+
+import javax.swing.text.html.HTMLEditorKit;
+import javax.swing.text.html.StyleSheet;
+import javax.swing.text.html.parser.DTD;
+import javax.swing.text.html.parser.ParserDelegator;
+import java.lang.reflect.Field;
+
+public class bug6938813 {
+    public static final String DTD_KEY = "dtd_key";
+
+    private static volatile StyleSheet styleSheet;
+
+    public static void main(String[] args) throws Exception {
+        // Run validation and init values for this AppContext
+        validate();
+
+        Thread thread = new ThreadInAnotherAppContext();
+
+        thread.start();
+        thread.join();
+    }
+
+    private static void validate() throws Exception {
+        AppContext appContext = AppContext.getAppContext();
+
+        assertTrue(DTD.getDTD(DTD_KEY).getName().equals(DTD_KEY), "DTD.getDTD() mixed AppContexts");
+
+        // Spoil hash value
+        DTD invalidDtd = DTD.getDTD("invalid DTD");
+
+        DTD.putDTDHash(DTD_KEY, invalidDtd);
+
+        assertTrue(DTD.getDTD(DTD_KEY) == invalidDtd, "Something wrong with DTD.getDTD()");
+
+        Object dtdKey = getParserDelegator_DTD_KEY();
+
+        assertTrue(appContext.get(dtdKey) == null, "ParserDelegator mixed AppContexts");
+
+        // Init default DTD
+        new ParserDelegator();
+
+        Object dtdValue = appContext.get(dtdKey);
+
+        assertTrue(dtdValue != null, "ParserDelegator.defaultDTD isn't initialized");
+
+        // Try reinit default DTD
+        new ParserDelegator();
+
+        assertTrue(dtdValue == appContext.get(dtdKey), "ParserDelegator.defaultDTD created a duplicate");
+
+        HTMLEditorKit htmlEditorKit = new HTMLEditorKit();
+
+        if (styleSheet == null) {
+            // First AppContext
+            styleSheet = htmlEditorKit.getStyleSheet();
+
+            assertTrue(styleSheet != null, "htmlEditorKit.getStyleSheet() returns null");
+            assertTrue(htmlEditorKit.getStyleSheet() == styleSheet, "Something wrong with htmlEditorKit.getStyleSheet()");
+        } else {
+            assertTrue(htmlEditorKit.getStyleSheet() != styleSheet, "HtmlEditorKit.getStyleSheet() mixed AppContexts");
+        }
+    }
+
+    private static void assertTrue(boolean b, String msg) {
+        if (!b) {
+            throw new RuntimeException("Test failed: " + msg);
+        }
+    }
+
+    private static Object getParserDelegator_DTD_KEY() throws Exception {
+        Field field = ParserDelegator.class.getDeclaredField("DTD_KEY");
+
+        field.setAccessible(true);
+
+        return field.get(null);
+    }
+
+    private static class ThreadInAnotherAppContext extends Thread {
+        public ThreadInAnotherAppContext() {
+            super(new ThreadGroup("6938813"), "ThreadInAnotherAppContext");
+        }
+
+        public void run() {
+            SunToolkit.createNewAppContext();
+
+            try {
+                validate();
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+}