VERY SERIOUS rmdir bug (really, "pwd" sh builtin)

[Doug Gwyn]

The BRL version of the SVR2 Bourne shell maintains an idea of the
current directory internally, and uses it when one tries a relative
"cd".  I set its idea of where I am initially by "cd $HOME" and
it never gets lost after that.  This is particulary important when
your file system is chock full of symbolic links to directories,
as ours is.  (Otherwise, "cd ..; rm -rf subdir" can be quite a
surprise when .. turns out to not be the place you just came from!)
Some people like this behavior, and some don't.  Now that I've tried
it for quite a while, I'm all for it.