all() in promised-io 0.3.0 cannot handle more than one rejected promise

[calmh]

When you try to do a all() around several promises and more than one of them get rejected, it fails with an "Error: This deferred has already been resolved". This seems to be due to the error callback being called immediately when the first rejection occurs, then again on the next rejected. It would perhaps be preferable to wait for all promises to either succeed or reject, and then call the appropriate callback? Or is there an obvious workaround/user error here? Example to reproduce:

var q = require('promised-io');

function fail(delay) {
    var d = q.defer();
    setTimeout(function () {
        d.reject(new Error('foo'));
    }, delay);
    return d.promise;
}

q.all(fail(250), fail(500)).then(function () {
    console.log("success");
}, function () {
    console.log("error");
});

Result:

% node ntest.js
error

timers.js:96
            if (!process.listeners('uncaughtException').length) throw e;
                                                                      ^
Error: This deferred has already been resolved
    at notifyAll (/Users/jb/src/zpoller/node_modules/promised-io/promise.js:164:10)
    at /Users/jb/src/zpoller/node_modules/promised-io/promise.js:229:3
    at notify (/Users/jb/src/zpoller/node_modules/promised-io/promise.js:199:22)
    at notifyAll (/Users/jb/src/zpoller/node_modules/promised-io/promise.js:179:5)
    at [object Object].<anonymous> (/Users/jb/src/zpoller/node_modules/promised-io/promise.js:229:3)
    at Object._onTimeout (/Users/jb/src/zpoller/ntest.js:6:11)
    at Timer.ontimeout (timers.js:94:19)