Osh hangs when reading a device file and piping through multiple commands to "head"

This is a weird one that I think we've boiled down to a minimal case:

This hangs:
`cat /dev/zero | cat | head -c 5`

This does not:
`cat /dev/zero | head -c 5`

(using /dev/urandom has the same issue)

It completes successfully without hanging in Bash.  Thanks in advance!  Oils rocks!