Reality and DOMCore disagree about document.ownerDocument

[fzzzy]

jQuery expects Document.ownerDocument to be null, and both Firefox and Chrome return null. dom.js depends on Document.ownerDocument being itself, and has a comment that says DOMCore requires it:

    // DOMCore says that documents are always associated with themselves.
    this.ownerDocument = this;

[fzzzy]

document.ownerDocument being document puts jQuery into an infinite loop.