3.6.1 produces eps files that are unusable on Debian wheezy

[Mike Miller]

I've been unable to display or convert eps files produced by print (to
gnuplot) with 3.6.1 on my Debian testing (wheezy) system, same result
on dev branch.  If I take these files to an older RHEL5 system, files
display fine.  This is most likely a problem with something else on my
system, but I'm trying to understand the difference so I know where to
look next.

I've put some time into comparing the results with different versions
of Octave and Ghostscript.  By diffing and manually editing the
intermediate files I'm pretty sure I've narrowed the problem down to
the font description for the plot axis tickmarks.

Octave 3.2.4 passes commands like the following to gnuplot:

    set xtics border in scale  1.4 mirror  font ",12";

which gnuplot turns into this snippet in the resulting eps file:

    [ [(Helvetica) 120.0 0.0 true true 0 (0.5)]

Octave 3.6.1 and dev both do the following instead:

    set xtics border in scale  1.4 mirror  font "{},20";

which passes through gnuplot into the eps file as:

    [ [({}) 200.0 0.0 true true 0 (0.5)]

Is this correct so far?  What is the meaning of the "{}" in a font
declaration like this?  At which stage is it supposed to be
interpreted into a valid font?  I'm not a PostScript expert, is this
supposed to be valid PostScript and there's a problem with my versions
of gs and evince?

Every program available on Debian fails to render the eps files with
"{}", for example gs 9.05 fails with "Error: /limitcheck in
/findfont".  However, as I said at the start, if I move the files to
RHEL5 with gs 8.15.2, no problem.  Or if I replace the {} with
Helvetica, no problem.

Any insight or tips on where to look next?

-- 
mike