pypa/virtualenv — pull request #364 by piotr-dobrogost (2012-11-25 19:09:51+00:00)
Title: Unset VIRTUAL_ENV environment variable. Fixes issue #9.

`activate.bat` sets `VIRTUAL_ENV` environment variable. This variable is treated as a sign that virtualenv is active. For this reason `deactivate.bat` should unset this variable.