Ignore the CYGWIN environment variable if child of a cygwin process?

[Christopher Faylor <cgf at redhat dot com>]

I keep seeing people who have set the CYGWIN environment variable from the bash
shell.  This causes strange problems.

I wonder if it would be worthwhile to ignore the CYGWIN environment variable
if it is set in a process that is a child of a cygwin process.

The downside is that there are probably some situations where it
actually works ok to do this and that we'll end up screwing up people
who know what they're doing.

We could just issue a warning but I hate for cygwin to be noisy in these kinds
of situations.

Any thoughts?

cgf