When using the f:ajax, or ace:ajax tags with MyFaces JSF it has been noted that there are some important differences in how MyFaces processes certain attribute values vs. Mojarra.

Specifically,

With MyFaces (execute=@none render=@all, and execute=@all render=@none), the difference with Mojarra is that the listener method is invoked in MyFaces, whereas it is not invoked in Mojarra. The expected outcome for the components that are executed/rendered according to the execute and render attributes is still correct in both cases. So, this seems to be more of a difference of how MyFaces and Mojarra handle ajax requests. It seems like MyFaces still executes the listener method, and if this method modifies the value of some property, then the components affected by that change are updated, while Mojarra simply doesn't render and/or execute anything. Another way of putting it is that Mojarra has a "hard" @none keyword and MyFaces has a soft @none keyword. This can be seen with a simple h:commandButton component using f:ajax.

Due to these differences, some of the ace:ajax regression tests fail on MyFaces:

     execute='@none', render='@all' Test : Expected Status = , Actual = fAjax aceAjax
        execute='@all', render='@none' Test : Expected Status = fAjax aceAjax , Actual = fAjax aceAjax fAjax
        onError JavaScript Callback Test : Expected Value A = 0, Actual value = 1, Expected Value B = 0, Actual value = 1

This seems like a likely MyFaces bug.