[Bug-tar] octal reading in spec

[NBC]

in the manual it's written

>The `chksum' field is the ASCII representation of the octal value of
>the simple sum of all bytes in the header block.  Each 8-bit byte in
>the header is added to an unsigned integer, initialized to zero, the
>precision of which shall be no less than seventeen bits.  When
>calculating the checksum, the `chksum' field is treated as if it were
>all blanks.

and when i check "tar-1.15.91.tar" i've got for the 1st entry
30 31 32 36 31 32 00 20

char chksum[8];               /* 148 */

30 31 32 36 31 32 is the checksum in octal
but what is 00 20

>All other fields are zero-filled
>octal numbers in ASCII.  Each numeric field of width W contains W minus
>1 digits, and a null.

shouldnt it have been
30 30 31 32 36 31 32 00
??

or anything after \0 is garbage