--- a/src/share/classes/com/sun/tools/javac/api/ClientCodeWrapper.java	Wed Aug 31 15:39:00 2011 -0700
+++ b/src/share/classes/com/sun/tools/javac/api/ClientCodeWrapper.java	Fri Sep 02 17:35:56 2011 +0100
@@ -609,6 +609,10 @@
         public String getMessage(Locale locale) {
             return d.getMessage(locale);
         }
+
+        public String toString() {
+            return d.toString();
+        }
     }
 
     protected class WrappedTaskListener implements TaskListener {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/tools/javac/api/7086261/T7086261.java	Fri Sep 02 17:35:56 2011 +0100
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 20011, 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 7086261
+ * @summary javac doesn't report error as expected, it only reports ClientCodeWrapper$DiagnosticSourceUnwrapper
+ */
+
+import javax.tools.*;
+
+import com.sun.tools.javac.api.ClientCodeWrapper.DiagnosticSourceUnwrapper;
+import com.sun.tools.javac.util.JCDiagnostic;
+
+import java.net.URI;
+import java.util.Arrays;
+
+import static javax.tools.StandardLocation.*;
+import static javax.tools.JavaFileObject.Kind.*;
+
+
+public class T7086261 {
+
+    static class ErroneousSource extends SimpleJavaFileObject {
+        public ErroneousSource() {
+            super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
+        }
+        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
+            return "class Test { NonexistentClass c = null; }";
+        }
+    }
+
+    static class DiagnosticChecker implements DiagnosticListener<javax.tools.JavaFileObject> {
+        public void report(Diagnostic message) {
+            if (!(message instanceof DiagnosticSourceUnwrapper)) {
+                throw new AssertionError("Wrapped diagnostic expected!");
+            }
+            String actual = message.toString();
+            JCDiagnostic jd = (JCDiagnostic)((DiagnosticSourceUnwrapper)message).d;
+            String expected = jd.toString();
+            if (!actual.equals(expected)) {
+                throw new AssertionError("expected = " + expected + "\nfound = " + actual);
+            }
+        }
+    };
+
+    void test() throws Throwable {
+        JavaCompiler javac = ToolProvider.getSystemJavaCompiler();
+        JavaFileManager jfm = javac.getStandardFileManager(null, null, null);
+        JavaCompiler.CompilationTask task =
+                javac.getTask(null, jfm, new DiagnosticChecker(), null, null, Arrays.asList(new ErroneousSource()));
+        task.call();
+    }
+
+    public static void main(String[] args) throws Throwable {
+        new T7086261().test();
+    }
+}