[fx] error in chaining _Animations from a combine

[gruppler]

When chaining two animation objects from dojo.fx.combine, the onPlay doesn't fire, and I get this error message:

exception in animation handler for: onAnimate
TypeError: second argument to Function.prototype.apply must be an array

Changing line 14 in dojo/fx.js from...

this[evt].apply(this, args||[]);

to...

this[evt].apply(this, (dojo.isArray(args) ? args : []));

silences the error, but the onPlay still does not fire.

Combining two chains, on the other hand, works perfectly. Attached is an example of a chain of two combines and a combine of two chains.

[dylan]

duplicate of #6490.