[Dev-luatex] \pdfmapfile and texconfig.trace_file_names

I've traced the problem to the routine fm_read_info in the file src/texk/web2c/luatexdir/font/mapfile.c. The tracefilenames flag is only honoured when the read_map_file callback is active. This would seem to be inconsistent with the treatment of \input where the flag is honoured irrespective of the find/open_read_file callbacks. James