zfsboot at 12.0: Shortening read at xxxx from 16 to -479991569

[Mark Martinec]

On one of my hosts (now running 12.0-RELEASE) the zfsboot shows
this weird negative number, which sounds suspicious:

   Verifying DMI pool Data .............
   Shortening read at 3907029152 from 16 to 15
   Shortening read at 7435283708 from 16 to -479991569

   BTX loader 1.0  BTX version is 1.02
   Consoles: ...
   BIOS drive C: is disk0
   ...

The machine boots up normally and is fine, zpool scrub is happy,
so, should I worry? Anything fishy there?

Searching through sources, the message seems to come from
stand/i386/zfsboot/zfsboot.c :

   printf("Shortening read at %lld from %d to %lld\n",
     alignlba, alignnb, (zdsk->dsk.size + zdsk->dsk.start) - alignlba);


Mark