[tex-live] last weekend changes

[Karl Berry]

    That way, people who just want to run broken code can easily insert

Here is my view: I feel it is imperative that the MANY existing
documents that test for pdf continue run unchanged.

And I don't agree with the characterization of them as "broken", if
that's what you're saying was broken.  Testing \ifx\pdfoutput\undefined
*was* (and remains!) an absolutely standard practice.

    I am not sure if we should provide an automatic feature that hides all
    pdftex primitives if people use e.g. latex. 

What is wrong with it?  It provides transparent compatibility.  I don't
understand why you think it is bad.

    to provide a TeX macro package that sets \pdfoutput to 0 and then sets
    all possibly relevant control sequences to \undefined.

\pdfoutput is one of those control sequences (the most important one, in
fact) to be undefined.  Setting it to 0 is not sufficient.  That's what
the whole discussion is about.

I would rather not use pdfetex than break old documents, if you prefer
that, but I see no reason why we can't accomplish both goals, with
Staszek's basic suggestion: undefine all the pdf primitives in the
latex.ini file (and others).  Yes, it is annoying for us.  Better some
annoyance for us than to break existing documents!

Hans' suggestion of a new primitive \pdfstate (by whatever name) that
can be switched back and forth would be even better.  I just don't know
how quickly it can be implemented.  If it is not available, once again,
I feel it is crucial that existing documents continue to work
*unchanged*, one way or another.  There are zillions upon zillions of them.

Please.

Thanks,
k