Not sure if this is a bug or just different behaviour than with node, but when using for example the bn.js module with trireme it's a problem.

When using trireme and create a buffer and try to get a minus index [-1] of the buffer it gives an ArrayIndexOutOfBoundsException. When I create then a second buffer with slice() from the first buffer and then try to get a minus index it gives a value. While using node I get undefined in both cases:

var buf1 = new Buffer("1111", "hex");
var buf2 = buf1.slice(1);

trireme:

console.log(buf1[-1]); // java.lang.ArrayIndexOutOfBoundsException: -1
console.log(buf2[-1]); // 17

node:

console.log(buf1[-1]); // undefined
console.log(buf2[-1]); // undefined