Description: when somebody tries to zoom out, we has a wrong order of steps to go:
Initially, the viewport is at (10000px, 0px), and the div element has a height of 10000px.
To adjust position, js requests viewport to scroll down by 2500px, however it hits the bottom of the div element, so it doesn't scroll down by 2500px as expected.
change height of a div element to a larger value, e.g. from 10000px to 12500px.
Finally, the viewport is kept at the position (10000px, 0px) but the div element is resized to 12500px.
If we reserve a larger height before scrolling, the wrong order steps doesn't bother.
fix #128.
Description: when somebody tries to zoom out, we has a wrong order of steps to go:
(10000px, 0px), and the div element has a height of10000px.2500px, however it hits the bottom of the div element, so it doesn't scroll down by2500pxas expected.10000pxto12500px.Finally, the viewport is kept at the position
(10000px, 0px)but the div element is resized to12500px.If we reserve a larger height before scrolling, the wrong order steps doesn't bother.