The following program should compile, but does not with 9 dev tip not with 8u40:

// ------ 8< --------
public class X {
public static void main(String[] args) {
new Neg19_01<Object>(null) {}; // OK.
}
}

class Neg19_01<T> {
private class Private {}
Neg19_01(Private p) {
System.out.println("Neg19_01");
}
}
// ------ 8< --------

The last para of 15.9.5.1 "Anonymous constructor reads":

"Note that it is possible for the signature of the anonymous constructor to refer
to an inaccessible type (for example, if such a type occurred in the signature of
the superclass constructor cs ). This does not, in itself, cause any errors at either
compile-time or run-time."

Thus this access check implemented by javac has no sanction in JLS.

ECJ compiles and run the code fine.