yui/yui3 — pull request #1465 by andrewnicols (2013-12-06 03:30:36+00:00)
Title: [io] Check whether a form still exists before resetting it

IO clears the form content on end, but if the caller removed the form soon
after it was called, this fails at a removeAttribute on part of the, now
non-existent form content.

We should check that the form exists before attempting to reset it.

Fixes #1121