I had an app where I was setting overflow: hidden on the body element and then using transforms to move unused objects off screen. Our viewport calculations seem to take those offscreen objects into account for their initial values though. For instance this test page: http://dl.dropboxusercontent.com/u/72157/overflow.html has an element that's transformed far off to the right. It results in a page that can't be scrolled horizontally, but is vertically really tall. You can generate similar (but slightly different) bugs if you transform it off the bottom of the page, where we'll allow scrolling the urlbar in and out even though we shouldn't allow scrolling at all.

So we don't properly support overflow:hidden on the root body element anyway. We have bug 886969 on file for that. If we fix that then this bug goes away, right?

The link in this page is now 404.

This sounds like bug 1423013 (or bug 1423709) Karl, what do you think?

Karl, ^

Without the initial markup from Wesley, it's a bit hard to know which one. Closing as INCOMPLETE for now without a test case to reproduce. We could still reopen or DUP against the right issue with a proper test case.