zsh and long running linux boxen

[David Benson <daveb@xxxxxxxx>]

This isn't a bug in zsh but it is a bug in the linux
kernel that only manifested itself in zsh for us.

The bug is:  on linux boxes that have been up
2^31/100 seconds, the select(2) system call trounces the
struct timeval that is the fifth argument.  This messes
up zsh's terminal handling.  (The bug in linux occurs when
the jiffies global variable runs into the sign bit) This is
about 248 days.

Yes, the bug _does_ go back away after another 248 days.

The symptoms are slightly different in different versions of
zsh.  In one, you must press enter twice to have your command run.
In the other, only one consecutive backspace shows up. The others
are tracked but not displayed.

- Dave Benson