Safari: NodeFilter workaround without spoofing?

[Guest]

Hy;

I detected that the createTreeWalker-implementation in Safari returns
only white-space text-nodes on NodeFilter.SHOW_TEXT. I could spoof for
Safari to fall-back too a generic tree-walk function, but I would
prefer a non-spoofing issue-detector.
One idea would to concat the content of all walked nodes and check if
it's only whitespace and then repeat the walk. But I'd rather not like
to use that.
Anybody got a smarter idea?

Ciao
Niels