[pdftex] font names in over/underfull box messages

[Vladimir Volovich]

"TTH" == The Thanh Han writes:

 TTH> I needed it when playing with font expansion, as expanded fonts
 TTH> have no associated macro name like \tenrm at all.

hm - but when you write e.g.

  \font\tenrm=cmr10
  \pdffontexpand\tenrm 30 20 10 1000

then pdftex will show this font as /cmr10/ instead of \tenrm and this
will not add any pdftex-specific info, so i see no need of changing
standard TeX's behavior.

also, with \pdffontexpand, the stretch/shrink/step/expand values are
bound to the font macro, in the above example, to \tenrm, so if we see
\tenrm we have exactly the same info as when we'll see /cmr10/

that's why i think that it's better to revert to compatibility with
TeX.

maybe it will make sense to add a new integer primitive which will be
a flag of whether to show the actual values of expansion selected for
fonts, e.g. if \pdftracefontnames=1, pdftex will show
"\tenrm(expanded 10) " instead of "\tenrm ".

but if \pdftracefontnames=0, standard TeX-style font names will be
shown.

also, when \pdftracefontnames=1, pdftex may change the way it shows
the \meaning\tenrm (or the same as \show\tenrm): instead of expanding
to "select font cmr10", pdftex can add "select font cmr10 stretch 30
shrink 20 step 10 expand 1000" or something like that.

Best,
v.