[css-position] Static position of abspos top layer elements inside fixed pos. · Issue #9939 · w3c/csswg-drafts (original) (raw)

This is the cyclic / ordering issue that I was concerned about in #8040.

Both Firefox and Blink get it wrong. WebKit gets it right, but I'm not sure what they're doing, maybe they're laying out the abspos twice?

The main issue here is that you have:

• Viewport box
  • ICB
    * Abspos
  • Fixedpos

So you lay out the abspos before the fixedpos, and the static position isn't computed yet.

cc @rlbuis @bfgeek @chrishtr