--- a/langtools/src/share/classes/com/sun/tools/javac/comp/Check.java	Thu Mar 05 17:24:08 2009 +0000
+++ b/langtools/src/share/classes/com/sun/tools/javac/comp/Check.java	Thu Mar 05 17:24:40 2009 +0000
@@ -1545,10 +1545,10 @@
 
 
     void checkNonCyclic(DiagnosticPosition pos, TypeVar t) {
-        checkNonCyclic1(pos, t, new HashSet<TypeVar>());
+        checkNonCyclic1(pos, t, List.<TypeVar>nil());
     }
 
-    private void checkNonCyclic1(DiagnosticPosition pos, Type t, Set<TypeVar> seen) {
+    private void checkNonCyclic1(DiagnosticPosition pos, Type t, List<TypeVar> seen) {
         final TypeVar tv;
         if  (t.tag == TYPEVAR && (t.tsym.flags() & UNATTRIBUTED) != 0)
             return;
@@ -1558,7 +1558,7 @@
             log.error(pos, "cyclic.inheritance", t);
         } else if (t.tag == TYPEVAR) {
             tv = (TypeVar)t;
-            seen.add(tv);
+            seen = seen.prepend(tv);
             for (Type b : types.getBounds(tv))
                 checkNonCyclic1(pos, b, seen);
         }

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/typevars/6804733/T6804733.java	Thu Mar 05 17:24:40 2009 +0000
@@ -0,0 +1,35 @@
+/*
+ * 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     6804733
+ * @summary javac generates spourious diagnostics for ill-formed type-variable bounds
+ * @author  mcimadamore
+ * @compile/fail/ref=T6804733.out -XDrawDiagnostics T6804733.java
+ */
+
+import java.util.ArrayList;
+class T6804733<S> extends ArrayList<S> {
+    <T extends S & S> void m() {}
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/generics/typevars/6804733/T6804733.out	Thu Mar 05 17:24:40 2009 +0000
@@ -0,0 +1,2 @@
+T6804733.java:34:20: compiler.err.type.var.may.not.be.followed.by.other.bounds
+1 error