Tooltip two-step appearance glitch

[JustinDrake]

Chrome for Mac.

1. Head to http://localhost:9001/javascript/#modals
2. Click on "Launch demo modal"
3. Hover over "This link" or "that link" and notice the tooltip appears twice, a few pixels off of each other.

[cvrebert]

Erm, is this #9638?

[JustinDrake]

Oh yes! But are you referencing a closed bug report?

[cvrebert]

Yes. Has the reproducibility situation changed since then?

[JustinDrake]

Don't think so. I can repro, for example, when document.width is 2021.

[mdo]

I think this is a positioning bug caused only by the rounding of half pixels—I can see a shifting tooltip at other odd browser widths as well. I imagine what needs to happen is that the position needs to be rounded up or down to the nearest whole pixel.

[fat]

ugh this is because we use jquery.offset() to position our tooltips… which doesn't round numbers.