Check for size overflow in tar header fields.
This prevents surprising outputs being created, e.g. this cpio tar
output with more than one file:
tar cf suffix.tar AUTHORS
dd if=/dev/zero seek=16G bs=1 count=0 of=suffix.tar
echo suffix.tar | cpio -H tar -o | tar tvf -
-rw-r--r-- 1000/1000 0 2019-08-30 16:40 suffix.tar
-rw-r--r-- thomas/thomas 161 2019-08-30 16:40 AUTHORS
Patch attached, but also at
https://cement.retrofitta.se/tmp/cpio-tar.patch--
☢ Thomas ☢