--- a/src/share/classes/sun/nio/cs/ISO_8859_1.java	Mon Jun 22 16:41:27 2009 -0700
+++ b/src/share/classes/sun/nio/cs/ISO_8859_1.java	Mon Jun 22 19:22:47 2009 -0700
@@ -142,7 +142,7 @@
         }
 
         public boolean isLegalReplacement(byte[] repl) {
-            return (repl.length == 1);  // we accept any byte value
+            return true;  // we accept any byte value
         }
 
         private final Surrogate.Parser sgp = new Surrogate.Parser();

--- a/src/share/classes/sun/nio/cs/US_ASCII.java	Mon Jun 22 16:41:27 2009 -0700
+++ b/src/share/classes/sun/nio/cs/US_ASCII.java	Mon Jun 22 19:22:47 2009 -0700
@@ -160,7 +160,8 @@
         }
 
         public boolean isLegalReplacement(byte[] repl) {
-            return (repl.length == 1 && repl[0] >= 0);
+            return (repl.length == 1 && repl[0] >= 0) ||
+                   super.isLegalReplacement(repl);
         }
 
         private final Surrogate.Parser sgp = new Surrogate.Parser();

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/sun/nio/cs/FindASCIIReplBugs.java	Mon Jun 22 19:22:47 2009 -0700
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2009 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 6847092
+ * @summary test if isLegalReplacement() works correctly for ascii charsets
+ */
+
+import java.util.*;
+import java.nio.*;
+import java.nio.charset.*;
+
+public class FindASCIIReplBugs {
+    private static int failures = 0;
+
+    public static void main(String[] args) throws Exception {
+        Charset ascii = Charset.forName("ASCII");
+        for (Map.Entry<String,Charset> e
+                 : Charset.availableCharsets().entrySet()) {
+            String csn = e.getKey();
+            Charset cs = e.getValue();
+            if (!cs.contains(ascii) ||
+                csn.matches(".*2022.*") ||             //iso2022 family
+                csn.matches(".*UTF-[16|32].*"))        //multi-bytes
+                continue;
+            if (! cs.canEncode()) continue;
+
+            byte[] sc_subs = { 'A'};
+            byte[] mc_subs = { 'A', 'S'};
+            if (!cs.newEncoder().isLegalReplacement (sc_subs) ||
+                !cs.newEncoder().isLegalReplacement (mc_subs)) {
+                System.out.printf(" %s: isLegalReplacement failed!%n", csn);
+                failures++;
+            }
+        }
+        if (failures > 0)
+            throw new Exception(failures + "tests failed");
+    }
+}