The fix basically works by adding a hidden submit button at the very beginning of the form. Its "name" is the same as for whatever current action is being performed. Thus, when enter is pressed, the same value is passed through.

In javascript mode, this form element's name attribute is poked every time a new element is configured to be correct for that. There is also some special event handling for the search tab of the artefact chooser, so it does not trigger a form submit - just a 'click' event on the correct button.