Only for the records of somebody interested, this is false. I was yesterday too tired, sorry. I’ll rewrite this paragraph:
I think the only solution multibrowser is encoding every character using, eg, a hexadecimal notation, so a “0A” is allways a “0A” when it arrives to the GURLGURL handler. This is the solution I suggested some time ago for Peter Bunn’s Missing Link, where it must be passed a file path to an applescript from random browsers.
However, the original solution is not still good enogh, since it only parses the mac-ascii table, eg: