Gecko's implementation of document.createTouch is not compatible with the Touch Events v1 spec, or the behavior of other browser.
This causes a failure in the createTouch test at:
Details? Which part of the test do we fail, and how does our behavior differ from other UAs?
Gecko expects separate clientX and clientY arguments to createTouch. These arguments are not present in other browsers. Other browsers set the clientX and clientY properties based on the pageX and pageY arguments.
The test failure is:
"assert_equals: touch.clientX is touch.pageX - window.pageXOffset. expected 15 but got 0"
Ah, I see. So just a matter of ripping out the client* from the _middle_ of the signature (and hoping no one is using it, fun) and computing them on the back end, ok....
The spec does not define how the clientX and clientY are computed. It probably needs to do that, if it's testing something about it.
*** Bug 815420 has been marked as a duplicate of this bug. ***
When this stuff was implemented, we followed the spec.