I was experimenting with enum, and I found that the following compiles and runs fine on Eclipse (Build id: 20090920-1017, not sure exact compiler version):

public class SwitchingOnAnull {
    enum X { ,; }
    public static void main(String[] args) {
        X x = null;
        switch(x) {
            default: System.out.println("Hello world!");
        }
    }
}

When compiled and run with Eclipse, this prints "Hello world!" and exits normally.

With the javac compiler, this throws a NullPointerException as expected.

So is there a bug in Eclipse Java compiler?