Message4343

The magic number is definitely system dependent. I just now tried this
on Jython 2.2/Java 1.6.0_03/WinXP, and only 511 was enough to hang the
script. Are you Jim possibly running on OS X like I've done before?

Notice that because the script automatically writes \n, the real number
of chars written to stderr is actually one more than the given number.
It's probably not just a coincident that pow(2, 9) == 512 and pow(2, 14)
== 16384.