iframe hit test is wrong

[paulrouget]

In the following example, the content of the iframe turns blue on :hover. But moving the mouse at the top or the bottom of the iframe, the content of the iframe is considered not :hover (so staying red). I guess it's a hit test issue. This makes clicking on links impossible in a more complex layout.

a.html:

<style>
  body {
    margin: 0;
  }

  div {
    width: 10px;
    height: 160px;
    background: green;
  }

  iframe {
    display: block;
    width: 200px;
    height: 200px;
    border: 0;
  }

</style>

<div></div>

<iframe src="b.html" mozbrowser="true"></iframe>

b.html:

<style>
  html { background: red }
  html:hover { background: blue }
</style>

[jdm]

I didn't expect b.html to work outside of an iframe, but it did. Interesting.