--- a/langtools/src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java	Thu Jun 17 16:28:21 2010 -0700
+++ b/langtools/src/share/classes/com/sun/tools/javac/jvm/ClassWriter.java	Fri Jun 18 15:12:04 2010 -0700
@@ -651,6 +651,13 @@
             endAttr(alenIdx);
             acount++;
         }
+        if ((flags & POLYMORPHIC_SIGNATURE) != 0) {
+            if (target.majorVersion < 51)
+                throw new AssertionError("PolymorphicSignature attributes in java/dyn must be written with -target 7 (required major version is 51, current is"+target.majorVersion+")");
+            int alenIdx = writeAttr(names.PolymorphicSignature);
+            endAttr(alenIdx);
+            acount++;
+        }
         return acount;
     }