I would expect the exception to bubble up to `promise`'s error handler, or am I wrong?

actual-promise.js

var Q = require('q');

var step1 = Q.promise(function (resolve, reject) { reject('an error on 1'); }); // <-- reject here
var step2 = Q.promise(function (resolve, reject) { resolve(2); });
var step3 = Q.promise(function (resolve, reject) { resolve(3); });
var step4 = Q.promise(function (resolve, reject) { resolve(4); });

step1.then(function (value) {
    console.log(value);
    return step2;
}).then(function (value) {
    console.log(value);
    return step3;
}).then(function (value) {
    console.log(value);
    return step4;
}).then(function (value) {
    console.log(value);
}).fail(function (reason) {
    console.log(reason); // <-- caught here
});

expected-promise.js

var Q = require('q');

var promise = Q.promise(function (resolve, reject) {
    setTimeout(function () {
        resolve("a nice value");
    }, 3000);
});

promise.then(function (value) {
    console.log(value);

    Q.fcall(function() {
        throw new Error("An error"); // <-- error gets thrown here
    });
}, function (reason) {
    console.log('Error', reason); // <-- error gets caught here
});