dfrotz core dumps if DAT file has no extension
I am working on a Ubuntu VBox instance on my Mac. When I downloaded the Zork I game, the file was just 'ZORKI' with no extension. This works file with frotz, but with dfrotz, it core dumps unless you rename the file to something like ZORKI.DAT.
From Debugger: Core was generated by `dfrotz ZORKI'. Program terminated with signal SIGSEGV, Segmentation fault. #0 0x0000563ae1ae932f in os_process_arguments (argc=2, argv=0x7ffc805451e8) at dumb_init.c:149 149 p = '\0'; / extension removed */