tests/test-issue433

osutil: cleanups

- use tabs
- eliminate old-style function pointer calls
- eliminate weird scoping
- eliminate assignment-in-iff
- use !foo rather than foo == NULL

#!/bin/sh
# http://www.selenic.com/mercurial/bts/issue433

hg init a
cd a
echo a > a
hg commit -Ama

hg parents -r 0 doesnotexist
true