Bug 404306

Description Mark Macdonald 2013-03-25 15:57:17 EDT

While investigating an update of GCLI, Grant found that the Orion Deferred doesn't work with the new GCLI. You can reproduce this as follows:
1. Upgrade the GCLI code in bundles/org.eclipse.orion.web.ui/web/gcli to the latest version of GCLI
2. Launch the Orion Node server
3. Go to the shell page and run any command that returns a Deferred. For example: "node start my_app.js"
4. A TypeError is thrown by the Orion Deferred. The command fails.

The reason is this GCLI code, which wraps the "then()" method from our Orion Deferred, and calls it without the dot operator:

> Requisition.prototype._then = function(thing, onDone, onError) {
>   var then = null;
>   if (thing != null && typeof thing.then === 'function') {
>     // Simple promises with a then function
>     then = thing.then;
>   }
>   ...
> 
>   if (then != null) {
>     then(onDone, onError); // XXX trouble
>   }
>   else {
>     onDone(thing);
>   }
> };

When the "then" method of Orion's Deferred is invoked without a receiver object, it blows up. The problematic code is:

> // Note: "then" ALWAYS returns before having onResolve or onReject called as per http://promises-aplus.github.com/promises-spec/
> this.then = function(onResolve, onReject, onProgress) {
>    ...
> 	var deferred = listener.deferred;
> 	var thisCancel = this.cancel.bind(this); // XXX fail here