anchor.diff:      ok = disk_log:truncate(n, apa),
       rec(1, {disk_log, node(), n, {truncated, 6}}),
       {0, 0} = no_overflows(n),
  -    22 = curb(n),
  +    23 = curb(n),
       1 = curf(n),
       1 = cur_cnt(n),
       true = (Size == sz(n)),
  
positive.code:     {ok, n} = disk_log:open([{name, n}, {file, File}, {type, wrap},
  			     {format, internal}, {mode, read_only}]),
      CrashFile = add_ext(File, 1),
      crash(CrashFile, 46), % the binary term {some,terms} is now bad
      {H1, [{this,is}], 16} = 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),
  
negative.code:     ok = disk_log:close(n),
      {ok, n} = disk_log:open([{name, n}, {file, File}, {type, halt},
  			     {format, internal}, {mode, read_only}]),
      crash(File, 51), % the binary term {some,terms} is now bad
      {J1, [{this,is}], 18} = disk_log:chunk(n, start, 10),
      {J2, [{on,a},{halt,file}]} = disk_log:chunk(n, J1),
      eof = disk_log:chunk(n, J2),
      ok = disk_log:close(n),
  