anchor.diff:      ok = disk_log:log_terms(n, [{some,terms}]), % second file full
       2 = curf(n),
       BadFile = add_ext(File, 1),
  -    crash(BadFile, 26), % the _binary_ is now invalid
  +    crash(BadFile, 28), % the _binary_ is now invalid
       {error, {corrupt_log_file, BFile}} = disk_log:chunk(n, start, 1),
       BadFile = BFile,
       ok = disk_log:close(n),
  
positive.code:     ok = disk_log:close(n),
      BadFile = add_ext(File, 2), % current file
      set_opened(BadFile),
      crash(BadFile, 26), % the binary is now invalid
      {repaired,n,{recovered,0},{badbytes,24}} =
  	disk_log:open([{name, n}, {file, File}, {type, wrap},
  		       {format, internal}, {size, {40,No}}]),
      ok = disk_log:close(n),
  
negative.code:     {ok, n} = disk_log:open([{name, n}, {file, File}, {type, wrap},
  			     {format, internal}, {mode, read_only}]),
      CrashFile = add_ext(File, 1),
      crash(CrashFile, 51), % the binary term {some,terms} is now bad
      {H1, [{this,is}], 18} = disk_log:chunk(n, start, 10),
      {H2, [{on,a},{wrap,file}]} = disk_log:chunk(n, H1),
      eof = disk_log:chunk(n, H2),
      ok = disk_log:close(n),
  