Off-by-one overflow (?)

[rustyBSD]

/usr/src/sbin/disklabel/disklabel.c
lines: 333 & 1092 & 1096

Is this me, or these strncpy() may cause off-by-one
overflows ?

In an use like this:

 strncpy(a, b, sizeof(a));

the null terminator will be added beyond the end of
a if b has the same size (or a larger size).

Should use something like:

 strncpy(a, b, sizeof(a) - 1);