From deraadt@ upstream:
Remove all getenv() calls, especially those wrapped by issetugid().
getenv()'s wrapped by issetugid() are safe, but issetugid() is ...
difficult to impliment on many operating systems. By accident, a grand
experiment was run over the last year, where issetugid() returned 1 (the
safe value) on a few operating systems. Noone noticed & complained that
certain environment variables were not working.......
