[tex-live] issue with `tlmgr paper` reporting undefined for pdftex

[jfbu]

Hi,

`tlmgr paper` outputs now in particular

Current pdftex paper size (from /usr/local/texlive/2015/texmf-dist/tex/generic/config/pdftexconfig.tex): (undefined)

and this seems to follow in change in pdftexconfig.tex
which on my installation appears to have added conditionals
since Oct 13 00:45, related to LuaTeX.

I was confronted with a problem with TeX Live Utility on Mac OS X,
which kept prompting me for specifying a system wide paper size,
and while issuing a ticket on its github site, I ended up
becoming aware of the above change in pdftexconfig.tex.

According to Time Machine, the file was changed only recently,
but I am not sure I can trust this 100%. In my archived TL2014
indeed there aren't the conditionals and TLU does not complain,
and tlmgr paper does report a4.

Is this a TeXLive issue ?

best

Jean-Francois