make check for grep 2.6.1.29 hangs in empty.sh under cygwin

[Shiva Iyer]

Under cygwin v 1.7.1, make check consistently hangs in empty.sh at line 25.
In fact, I can get it to hang by running the following from a prompt.

echo "abcd" | src/grep -F -x -f /dev/null > /dev/null 2>&1

This was against the latest GIT sources for grep and after doing a make
clean, bootstrap, configure and make.

Thanks,

Shiva