Re: [PATCH] git-init: set core.worktree if GIT_WORK_TREE is specified

+	if (!getcwd(cwd, sizeof(cwd)) || cwd[0] != '/')
+		die("Unable to read current working directory");

Dscho just pointed out that this causes problems on windows.  The same
is also in setup_git_directory_gently and was there before I touched
it, introduced by Linus in d288a700.  What was the original reason to
do this?  Are there implementations of getcwd which return a relative
path?

Additionally there are other places which need to check if some user
supplied path is absolute.  Should we have a macro/function for that
which depends on the os and checks for path[0] = '/' on unix and
perhaps path[1] = ':' on windows?