Test the "scrollTop" properties on the body element in quirks mode.

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".


Initial values
PASS document.body.scrollLeft is 0
PASS document.body.scrollTop is 0
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 0
PASS window.scrollY is 0

Let set the scrollTop value on the main body element (document.body), in quirks mode, this should change the main frame's scroll position.
PASS document.body.scrollTop = 42 is 42
PASS document.body.scrollLeft is 0
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 0
PASS window.scrollY is 42

Change scrollX, this should have no effect on the vertical scrolling
PASS window.scrollBy(21, 0) is undefined
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

Now we create a body element, completely detached from the DOM tree. This should not change the scroll position in any way.
PASS floatingBody.scrollLeft is 0
PASS floatingBody.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

Setting the scroll position on that detached body element should not affect the main frame since it is not the first body element of the document.
PASS floatingBody.scrollTop = 500 is 500
PASS floatingBody.scrollLeft is 0
PASS floatingBody.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

We add a new body element after the first body element, this should have no impact on the state.
PASS secondSiblingBody.scrollLeft is 0
PASS secondSiblingBody.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

Setting a "scrollTop" on secondSiblingBody should not affect the main frame.
PASS secondSiblingBody.scrollTop = 321 is 321
PASS secondSiblingBody.scrollLeft is 0
PASS secondSiblingBody.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

We add a new body element inside the first body element, this should have no impact on the state.
PASS bodyChildOfMainBody.scrollLeft is 0
PASS bodyChildOfMainBody.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

Setting a "scrollTop" on bodyChildOfMainBody should not affect the main frame.
PASS bodyChildOfMainBody.scrollTop = 57 is 57
PASS bodyChildOfMainBody.scrollLeft is 0
PASS bodyChildOfMainBody.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

Now we insert a new body element *before* the existing one. It will replace the existing element as the first body element of the document.
PASS document.body === newMainBody is true
PASS document.body !== oldBodyElement is true
Since we are in quirks mode, the new body element gets the scroll position from the frame, and the old one lose its scroll position.
PASS oldBodyElement.scrollLeft is 0
PASS oldBodyElement.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 42
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 42

Scrolling that new body should work as expected.
PASS document.body.scrollTop = 68 is 68
PASS oldBodyElement.scrollTop = 894 is 894
PASS oldBodyElement.scrollLeft is 0
PASS oldBodyElement.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 68
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 68

Scrolling the main frame should not require a renderer.
PASS document.body.style.display = 'none' is 'none'
PASS document.body.scrollTop = 54 is 54
PASS oldBodyElement.scrollLeft is 0
PASS oldBodyElement.scrollTop is 0
PASS document.body.scrollLeft is 21
PASS document.body.scrollTop is 54
PASS document.documentElement.scrollLeft is 0
PASS document.documentElement.scrollTop is 0
PASS window.scrollX is 21
PASS window.scrollY is 54
PASS successfullyParsed is true

TEST COMPLETE