[luatex] virtual font example from the documentation

[Herbert Voss]

This is an example from the LuaTeX documentation (pp 166--167)
which works well in the past.

\directlua {
  callback.register('define_font',
    function (name,size)
      if name == 'cmr10-red' then
		f = font.read_tfm('cmr10',size)
		f.name = 'cmr10-red'
		f.type = 'virtual'
		f.fonts = {{ name = 'cmr10', size = size }}
		for i,v in pairs(f.characters) do
		  if (string.char(i)):find('[tacohanshartmut]') then
			v.commands = {{'special','pdf: 1 0 0 rg'},{'char',i},{'special','pdf:
0 g'},}
		  else
			v.commands = {{'char',i}}
		  end
		end
	  else
		f = font.read_tfm(name,size)
	  end
      return f
    end)
}

\font\myfont = cmr10-red at 10pt \myfont This is a line of text \par
\font\myfontx= cmr10 at 10pt \myfontx Here is another line of text

\bye


But with current up-to-date TeXLive I get a segmentation fault:

This is LuaTeX, Version beta-0.79.1 (TeX Live 2014/dev) (rev 4972)
 restricted \write18 enabled.
(./vfont.texSpeicherzugriffsfehler
[ ... ]

or at least a wrong output, the character table is missing:

voss at shania:~/tmp> luatex vfont.tex
This is LuaTeX, Version beta-0.79.1 (TeX Live 2014/dev) (rev 4972)
 restricted \write18 enabled.
(./vfont.tex
LuaTeX warning: lua-loaded font [51] (cmr10-red) has no character table!
[1{/usr/local/texlive/2014/texmf-var/fonts/map/pdftex/updmap/pdftex.map}])
(see the transcript file for additional
information)<</usr/local/texlive/2014/te
xmf-dist/fonts/type1/public/amsfonts/cm/cmr10.pfb>
Output written on vfont.pdf (1 page, 13026 bytes).
Transcript written on vfont.log.

---------------------------------------------------------------------

If I use the updated callback syntax:

\input luatexbase.sty

\directlua {
  luatexbase.add_to_callback('define_font',
    function (name,size)
[ ... ]
----------------------------------------------------------------------

then I always get a segmentation fault.


Can someone confirm this behaviour?

Herbert