add: case 10 :    case 13 : break;
context: drill_file_p(gerb_file_t *fd){    char read[2];    while ((read[0] = gerb_fgetc(fd)) != EOF) {        switch (read[0]) {        case 'M':            if(gerb_fgetc(fd) == '4') {		if(gerb_fgetc(fd) == '8') {                /* Drill file header command found,                   this could very well be a drill file */		fd->ptr = 0;                return 1;		}	    }	    eat_line(fd);            break;	case 'T':	    /* Something that looks like a tool definition found.	       Special case to allow files from Orcad, which sucks. */	    fd->ptr = 0;	    return 1;	case 'X':	case 'Y':	    /* First coordinate reached without finding any sign of this	       being a drill file. Stop parsing and return. */	    fd->ptr = 0;	    return 0;        default :            eat_line(fd);            break;        }    }    /* This is, in all likelyhood, not a drill file */    fd->ptr = 0;    return 0;}