node and xref with and without commands

[Karl Berry]

Hi Patrice,

Consider:

------------------------------
\input texinfo
@setfilename xrefat.info

@node @code{Top}
@top Xrefat

@xref{Top}.

@bye
------------------------------

There is a "plain text" xref to a node name that uses commands,
though the expanded node name matches the text.

This goes through makeinfo without any problem.
I think it would be good for there to be a warning, or even an error,

I don't have a strong argument for the above example, it's just the
simplest one.  Where I ran across this in practice was with:

@node Use @TeX{}
..
@xref{Use TeX}.

In this case, makeinfo also does not complain, but the xref in the pdf
output does not resolve (there is a warning from pdftex), for obscure
PDF/TeXnical reasons.

In principle it seems like it is undesirable for documents to be able to
"shortcut" the xref with the expansion of the command in the node name
and have it work.

Wdyt?

Thanks,
k