diff -r ddec8c712e85 -r f5b5112ee1cc src/share/classes/com/sun/tools/javac/comp/Attr.java
--- a/src/share/classes/com/sun/tools/javac/comp/Attr.java	Tue Mar 29 16:40:31 2011 +0100
+++ b/src/share/classes/com/sun/tools/javac/comp/Attr.java	Tue Mar 29 16:40:51 2011 +0100
@@ -1580,7 +1580,7 @@
         // Attribute clazz expression and store
         // symbol + type back into the attributed tree.
         Type clazztype = attribType(clazz, env);
-        Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype, cdef != null);
+        Pair<Scope,Scope> mapping = getSyntheticScopeMapping(clazztype);
         clazztype = chk.checkDiamond(tree, clazztype);
         chk.validate(clazz, localEnv);
         if (tree.encl != null) {
@@ -1778,62 +1778,48 @@
                         Pair<Scope, Scope> mapping,
                         List<Type> argtypes,
                         List<Type> typeargtypes) {
-        if (clazztype.isErroneous() || mapping == erroneousMapping) {
+        if (clazztype.isErroneous() ||
+                clazztype.isInterface() ||
+                mapping == erroneousMapping) {
             //if the type of the instance creation expression is erroneous,
-            //or something prevented us to form a valid mapping, return the
-            //(possibly erroneous) type unchanged
+            //or if it's an interface, or if something prevented us to form a valid
+            //mapping, return the (possibly erroneous) type unchanged
             return clazztype;
         }
-        else if (clazztype.isInterface()) {
-            //if the type of the instance creation expression is an interface
-            //skip the method resolution step (JLS 15.12.2.7). The type to be
-            //inferred is of the kind <X1,X2, ... Xn>C<X1,X2, ... Xn>
-            clazztype = new ForAll(clazztype.tsym.type.allparams(), clazztype.tsym.type) {
-                @Override
-                public List<Type> getConstraints(TypeVar tv, ConstraintKind ck) {
-                    switch (ck) {
-                        case EXTENDS: return types.getBounds(tv);
-                        default: return List.nil();
-                    }
-                }
-                @Override
-                public Type inst(List<Type> inferred, Types types) throws Infer.NoInstanceException {
-                    // check that inferred bounds conform to their bounds
-                    infer.checkWithinBounds(tvars,
-                           types.subst(tvars, tvars, inferred), Warner.noWarnings);
-                    return super.inst(inferred, types);
-                }
-            };
+
+        //dup attribution environment and augment the set of inference variables
+        Env<AttrContext> localEnv = env.dup(tree);
+        localEnv.info.tvars = clazztype.tsym.type.getTypeArguments();
+
+        //if the type of the instance creation expression is a class type
+        //apply method resolution inference (JLS 15.12.2.7). The return type
+        //of the resolved constructor will be a partially instantiated type
+        ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
+        Symbol constructor;
+        try {
+            constructor = rs.resolveDiamond(tree.pos(),
+                    localEnv,
+                    clazztype.tsym.type,
+                    argtypes,
+                    typeargtypes);
+        } finally {
+            ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
+        }
+        if (constructor.kind == MTH) {
+            ClassType ct = new ClassType(clazztype.getEnclosingType(),
+                    clazztype.tsym.type.getTypeArguments(),
+                    clazztype.tsym);
+            clazztype = checkMethod(ct,
+                    constructor,
+                    localEnv,
+                    tree.args,
+                    argtypes,
+                    typeargtypes,
+                    localEnv.info.varArgs).getReturnType();
         } else {
-            //if the type of the instance creation expression is a class type
-            //apply method resolution inference (JLS 15.12.2.7). The return type
-            //of the resolved constructor will be a partially instantiated type
-            ((ClassSymbol) clazztype.tsym).members_field = mapping.snd;
-            Symbol constructor;
-            try {
-                constructor = rs.resolveDiamond(tree.pos(),
-                        env,
-                        clazztype.tsym.type,
-                        argtypes,
-                        typeargtypes);
-            } finally {
-                ((ClassSymbol) clazztype.tsym).members_field = mapping.fst;
-            }
-            if (constructor.kind == MTH) {
-                ClassType ct = new ClassType(clazztype.getEnclosingType(),
-                        clazztype.tsym.type.getTypeArguments(),
-                        clazztype.tsym);
-                clazztype = checkMethod(ct,
-                        constructor,
-                        env,
-                        tree.args,
-                        argtypes,
-                        typeargtypes,
-                        env.info.varArgs).getReturnType();
-            } else {
-                clazztype = syms.errType;
-            }
+            clazztype = syms.errType;
         }
+
         if (clazztype.tag == FORALL && !pt.isErroneous()) {
             //if the resolved constructor's return type has some uninferred
             //type-variables, infer them using the expected type and declared
@@ -1863,34 +1849,28 @@
      *  inference. The inferred return type of the synthetic constructor IS
      *  the inferred type for the diamond operator.
      */
-    private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype, boolean overrideProtectedAccess) {
+    private Pair<Scope, Scope> getSyntheticScopeMapping(Type ctype) {
         if (ctype.tag != CLASS) {
             return erroneousMapping;
         }
+
         Pair<Scope, Scope> mapping =
                 new Pair<Scope, Scope>(ctype.tsym.members(), new Scope(ctype.tsym));
-        List<Type> typevars = ctype.tsym.type.getTypeArguments();
+
+        //for each constructor in the original scope, create a synthetic constructor
+        //whose return type is the type of the class in which the constructor is
+        //declared, and insert it into the new scope.
         for (Scope.Entry e = mapping.fst.lookup(names.init);
                 e.scope != null;
                 e = e.next()) {
-            MethodSymbol newConstr = (MethodSymbol) e.sym.clone(ctype.tsym);
-            if (overrideProtectedAccess && (newConstr.flags() & PROTECTED) != 0) {
-                //make protected constructor public (this is required for
-                //anonymous inner class creation expressions using diamond)
-                newConstr.flags_field |= PUBLIC;
-                newConstr.flags_field &= ~PROTECTED;
-            }
-            newConstr.name = names.init;
-            List<Type> oldTypeargs = List.nil();
-            if (newConstr.type.tag == FORALL) {
-                oldTypeargs = ((ForAll) newConstr.type).tvars;
-            }
-            newConstr.type = new MethodType(newConstr.type.getParameterTypes(),
-                    new ClassType(ctype.getEnclosingType(), ctype.tsym.type.getTypeArguments(), ctype.tsym),
-                    newConstr.type.getThrownTypes(),
-                    syms.methodClass);
-            newConstr.type = new ForAll(typevars.prependList(oldTypeargs), newConstr.type);
-            mapping.snd.enter(newConstr);
+            Type synthRestype = new ClassType(ctype.getEnclosingType(),
+                        ctype.tsym.type.getTypeArguments(),
+                        ctype.tsym);
+            MethodSymbol synhConstr = new MethodSymbol(e.sym.flags(),
+                    names.init,
+                    types.createMethodTypeWithReturn(e.sym.type, synthRestype),
+                    e.sym.owner);
+            mapping.snd.enter(synhConstr);
         }
         return mapping;
     }