--- a/src/share/classes/javax/swing/text/AbstractDocument.java	Wed Aug 28 17:25:35 2013 +0400
+++ b/src/share/classes/javax/swing/text/AbstractDocument.java	Wed Aug 28 17:32:25 2013 +0400
@@ -934,16 +934,18 @@
      * Returns true if the text in the range <code>p0</code> to
      * <code>p1</code> is left to right.
      */
-    boolean isLeftToRight(int p0, int p1) {
-        if(!getProperty(I18NProperty).equals(Boolean.TRUE)) {
-            return true;
-        }
-        Element bidiRoot = getBidiRootElement();
-        int index = bidiRoot.getElementIndex(p0);
-        Element bidiElem = bidiRoot.getElement(index);
-        if(bidiElem.getEndOffset() >= p1) {
-            AttributeSet bidiAttrs = bidiElem.getAttributes();
-            return ((StyleConstants.getBidiLevel(bidiAttrs) % 2) == 0);
+    static boolean isLeftToRight(Document doc, int p0, int p1) {
+        if (Boolean.TRUE.equals(doc.getProperty(I18NProperty))) {
+            if (doc instanceof AbstractDocument) {
+                AbstractDocument adoc = (AbstractDocument) doc;
+                Element bidiRoot = adoc.getBidiRootElement();
+                int index = bidiRoot.getElementIndex(p0);
+                Element bidiElem = bidiRoot.getElement(index);
+                if (bidiElem.getEndOffset() >= p1) {
+                    AttributeSet bidiAttrs = bidiElem.getAttributes();
+                    return ((StyleConstants.getBidiLevel(bidiAttrs) % 2) == 0);
+                }
+            }
         }
         return true;
     }

--- a/src/share/classes/javax/swing/text/DefaultCaret.java	Wed Aug 28 17:25:35 2013 +0400
+++ b/src/share/classes/javax/swing/text/DefaultCaret.java	Wed Aug 28 17:32:25 2013 +0400
@@ -1211,12 +1211,9 @@
 
     boolean isPositionLTR(int position, Position.Bias bias) {
         Document doc = component.getDocument();
-        if(doc instanceof AbstractDocument ) {
-            if(bias == Position.Bias.Backward && --position < 0)
-                position = 0;
-            return ((AbstractDocument)doc).isLeftToRight(position, position);
-        }
-        return true;
+        if(bias == Position.Bias.Backward && --position < 0)
+            position = 0;
+        return AbstractDocument.isLeftToRight(doc, position, position);
     }
 
     Position.Bias guessBiasForOffset(int offset, Position.Bias lastBias,

--- a/src/share/classes/javax/swing/text/GlyphPainter2.java	Wed Aug 28 17:25:35 2013 +0400
+++ b/src/share/classes/javax/swing/text/GlyphPainter2.java	Wed Aug 28 17:32:25 2013 +0400
@@ -239,10 +239,10 @@
                                              Position.Bias[] biasRet)
             throws BadLocationException {
 
+            Document doc = v.getDocument();
             int startOffset = v.getStartOffset();
             int endOffset = v.getEndOffset();
             Segment text;
-            AbstractDocument doc;
             boolean viewIsLeftToRight;
             TextHitInfo currentHit, nextHit;
 
@@ -252,8 +252,7 @@
             case View.SOUTH:
                 break;
             case View.EAST:
-                doc = (AbstractDocument)v.getDocument();
-                viewIsLeftToRight = doc.isLeftToRight(startOffset, endOffset);
+                viewIsLeftToRight = AbstractDocument.isLeftToRight(doc, startOffset, endOffset);
 
                 if(startOffset == doc.getLength()) {
                     if(pos == -1) {
@@ -313,8 +312,7 @@
                 }
                 return pos;
             case View.WEST:
-                doc = (AbstractDocument)v.getDocument();
-                viewIsLeftToRight = doc.isLeftToRight(startOffset, endOffset);
+                viewIsLeftToRight = AbstractDocument.isLeftToRight(doc, startOffset, endOffset);
 
                 if(startOffset == doc.getLength()) {
                     if(pos == -1) {

--- a/src/share/classes/javax/swing/text/ParagraphView.java	Wed Aug 28 17:25:35 2013 +0400
+++ b/src/share/classes/javax/swing/text/ParagraphView.java	Wed Aug 28 17:32:25 2013 +0400
@@ -267,8 +267,6 @@
               throws BadLocationException {
         JTextComponent text = (JTextComponent)getContainer();
         Document doc = getDocument();
-        AbstractDocument aDoc = (doc instanceof AbstractDocument) ?
-                                (AbstractDocument)doc : null;
         View row = getView(rowIndex);
         int lastPos = -1;
         // This could be made better to check backward positions too.
@@ -276,8 +274,7 @@
         for(int vc = 0, numViews = row.getViewCount(); vc < numViews; vc++) {
             View v = row.getView(vc);
             int start = v.getStartOffset();
-            boolean ltr = (aDoc != null) ? aDoc.isLeftToRight
-                           (start, start + 1) : true;
+            boolean ltr = AbstractDocument.isLeftToRight(doc, start, start + 1);
             if(ltr) {
                 lastPos = start;
                 for(int end = v.getEndOffset(); lastPos < end; lastPos++) {
@@ -338,12 +335,8 @@
     protected boolean flipEastAndWestAtEnds(int position,
                                             Position.Bias bias) {
         Document doc = getDocument();
-        if(doc instanceof AbstractDocument &&
-           !((AbstractDocument)doc).isLeftToRight(getStartOffset(),
-                                                  getStartOffset() + 1)) {
-            return true;
-        }
-        return false;
+        position = getStartOffset();
+        return !AbstractDocument.isLeftToRight(doc, position, position + 1);
     }
 
     // --- FlowView methods ---------------------------------------------

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/javax/swing/text/AbstractDocument/6968363/Test6968363.java	Wed Aug 28 17:32:25 2013 +0400
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2013, 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.
+ */
+import sun.awt.SunToolkit;
+
+import java.awt.Robot;
+import javax.swing.JFrame;
+import javax.swing.JLabel;
+import javax.swing.JTextField;
+import javax.swing.event.DocumentListener;
+import javax.swing.event.UndoableEditListener;
+import javax.swing.text.AttributeSet;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.Document;
+import javax.swing.text.Element;
+import javax.swing.text.PlainDocument;
+import javax.swing.text.Position;
+import javax.swing.text.Segment;
+
+import static java.awt.BorderLayout.NORTH;
+import static java.awt.BorderLayout.SOUTH;
+import static java.awt.Toolkit.getDefaultToolkit;
+import static java.awt.event.KeyEvent.VK_LEFT;
+import static javax.swing.SwingUtilities.invokeAndWait;
+
+/*
+ * @test
+ * @bug 6968363
+ * @summary Ensures that a custom document may not extend AbstractDocument
+ * @author Sergey Malenkov
+ */
+public class Test6968363 implements Runnable, Thread.UncaughtExceptionHandler {
+    private JFrame frame;
+
+    public static void main(String[] args) throws Exception {
+        SunToolkit toolkit = (SunToolkit) getDefaultToolkit();
+        Runnable task = new Test6968363();
+        invokeAndWait(task);
+        toolkit.realSync(100);
+        new Robot().keyPress(VK_LEFT);
+        toolkit.realSync(100);
+        invokeAndWait(task);
+    }
+
+    @Override
+    public void uncaughtException(Thread thread, Throwable throwable) {
+        throwable.printStackTrace();
+        System.exit(1);
+    }
+
+    @Override
+    public void run() {
+        if (this.frame == null) {
+            Thread.setDefaultUncaughtExceptionHandler(this);
+            this.frame = new JFrame(getClass().getSimpleName());
+            this.frame.add(NORTH, new JLabel("Copy Paste a HINDI text into the field below"));
+            this.frame.add(SOUTH, new JTextField(new MyDocument(), "\u0938", 10));
+            this.frame.pack();
+            this.frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
+            this.frame.setLocationRelativeTo(null);
+            this.frame.setVisible(true);
+        } else {
+            this.frame.dispose();
+            this.frame = null;
+        }
+    }
+
+    private static class MyDocument implements Document {
+        private final Document document = new PlainDocument();
+
+        @Override
+        public int getLength() {
+            return this.document.getLength();
+        }
+
+        @Override
+        public void addDocumentListener(DocumentListener listener) {
+            this.document.addDocumentListener(listener);
+        }
+
+        @Override
+        public void removeDocumentListener(DocumentListener listener) {
+            this.document.removeDocumentListener(listener);
+        }
+
+        @Override
+        public void addUndoableEditListener(UndoableEditListener listener) {
+            this.document.addUndoableEditListener(listener);
+        }
+
+        @Override
+        public void removeUndoableEditListener(UndoableEditListener listener) {
+            this.document.removeUndoableEditListener(listener);
+        }
+
+        @Override
+        public Object getProperty(Object key) {
+            return this.document.getProperty(key);
+        }
+
+        @Override
+        public void putProperty(Object key, Object value) {
+            this.document.putProperty(key, value);
+        }
+
+        @Override
+        public void remove(int offset, int length) throws BadLocationException {
+            this.document.remove(offset, length);
+        }
+
+        @Override
+        public void insertString(int offset, String string, AttributeSet set) throws BadLocationException {
+            for (int i = 0; i < string.length(); i++) {
+                System.out.println("i: " + i + "; ch: " + Integer.toHexString(string.charAt(i)));
+            }
+            this.document.insertString(offset, string, set);
+        }
+
+        @Override
+        public String getText(int offset, int length) throws BadLocationException {
+            return this.document.getText(offset, length);
+        }
+
+        @Override
+        public void getText(int offset, int length, Segment segment) throws BadLocationException {
+            this.document.getText(offset, length, segment);
+        }
+
+        @Override
+        public Position getStartPosition() {
+            return this.document.getStartPosition();
+        }
+
+        @Override
+        public Position getEndPosition() {
+            return this.document.getEndPosition();
+        }
+
+        @Override
+        public Position createPosition(int offset) throws BadLocationException {
+            return this.document.createPosition(offset);
+        }
+
+        @Override
+        public Element[] getRootElements() {
+            Element[] elements = this.document.getRootElements();
+            Element[] wrappers = new Element[elements.length];
+            for (int i = 0; i < elements.length; i++) {
+                wrappers[i] = new MyElement(elements[i]);
+            }
+            return wrappers;
+        }
+
+        @Override
+        public Element getDefaultRootElement() {
+            return new MyElement(this.document.getDefaultRootElement());
+        }
+
+        @Override
+        public void render(Runnable task) {
+            this.document.render(task);
+        }
+
+        private class MyElement implements Element {
+            private final Element element;
+
+            private MyElement(Element element) {
+                this.element = element;
+            }
+
+            @Override
+            public Document getDocument() {
+                return MyDocument.this;
+            }
+
+            @Override
+            public Element getParentElement() {
+                return new MyElement(this.element.getParentElement());
+            }
+
+            @Override
+            public String getName() {
+                return this.element.getName();
+            }
+
+            @Override
+            public AttributeSet getAttributes() {
+                return this.element.getAttributes();
+            }
+
+            @Override
+            public int getStartOffset() {
+                return this.element.getStartOffset();
+            }
+
+            @Override
+            public int getEndOffset() {
+                return this.element.getEndOffset();
+            }
+
+            @Override
+            public int getElementIndex(int offset) {
+                return this.element.getElementIndex(offset);
+            }
+
+            @Override
+            public int getElementCount() {
+                return this.element.getElementCount();
+            }
+
+            @Override
+            public Element getElement(int index) {
+                return new MyElement(this.element.getElement(index));
+            }
+
+            @Override
+            public boolean isLeaf() {
+                return this.element.isLeaf();
+            }
+        }
+    }
+}