When the visibility of the last child whitespace node is invoked, and when hovering over this whitespace node, styles applied to the :hover state of sibling elements match the first child sibling element in that series.

This issue relates to this issue. You need to install the Ahem font to be able to view this test case properly

There are several different combinations of conditions that can trigger this bug.

When hovering over the grey-colored area (with the words 'Hover here'), the color of the preceding inline box should not change to red.

With preceding block-level sibling

For clarities sake, the preceding block-level sibling in the example below has been hidden. To trigger the bug, this hidden (or visible) element must have a font-size equal to, or smaller than the first child inline element.

With a border value applied to parent

The example below applies a border value to all four sides of the box, although only specifiying a border on one side will suffice.

With an overflow value (other than 'visible') applied to parent