Incoherent invocation type inference?

[B. Blaser]

Hi,

I encountered a strange behavior in the the case of a poly expression
method invocation (with 'null' or without parameter) that doesn't
provide any explicit type argument (JLS 18.5.2).

The following code:

import java.util.*;

public class Issue  {
    <T extends Iterable<String>> T get() { return (T)new ArrayList<String>(); }
    <T extends Iterable<String>> T get(T t) { return (T)new
ArrayList<String>(); }

    void run() {
        List<String> li = null;
        LinkedList<String> ll = null;
        Integer i = null;

        li = get(null);
        i = get(null); // Shouldn't compile? and will fail at runtime.
//        i = get(li); // Fails as expected

        li = get();
        ll = get(); // OK, but will fail at runtime due to unchecked
conversion in get().
        i = get(); // Shouldn't compile? and will fail at runtime.
    }

    public static void main(String... args) {
        new Issue().run();
    }
}

...is translated as follows before code generation:

public class Issue {

    public Issue() {
        super();
    }

    Iterable get() {
        return (Iterable)new ArrayList();
    }

    Iterable get(Iterable t) {
        return (Iterable)new ArrayList();
    }

    void run() {
        List li = null;
        LinkedList ll = null;
        Integer i = null;
        li = (List)get(null);
        i = (Integer)get(null);
        li = (List)get();
        ll = (LinkedList)get();
        i = (Integer)get();
    }

    public static void main(String... args) {
        new Issue().run();
    }
}

The next line is OK, but will fail at runtime due to unchecked
converstion in get():
    ll = (LinkedList)get();

But the following lines are more surprising:
    i = (Integer)get(null);
    i = (Integer)get();

They will, of course, fail at runtime with ClassCastException. I think
that javac behavior is probably in compliance with JLS 18.5.2, but is
this really coherent?

Thanks,
Bernard