[tex-live] error on (after) texlive 2008 installation

[Karl Berry]

    How can this feature be detected at TeX macro level in a robust
    and easy way?

Heiko, as you've pointed out before, the quote "feature" is not
especially useful for macro writers, and what would be more useful is an
extending \input to delimit the filename by catcode1 and catcode2
tokens.

I don't think there are any compatibility problems with that, even given
LaTeX's redefinition of \input.  All existing code should work
unchanged, seems to me, since the input is erroneous now.

It's more tex hacking than I can take on right now.  If you or anyone
else would like to work on it, sounds good to me.

I guess we'd have to add something like \pdfinputacceptsgroupdelimiters
register to make it practical to detect.  Hopefully with a better name.

    What's the specification of this syntax?

The "foo bar" feature is documented in the web2c manual.  I don't know if
miktex implements it.