missing prompt in invalid dir

[Volker Gropp]

Describe the bug
there is no prompt at all when your cwd does not exist or you don't have any permissions

To Reproduce
Steps to reproduce the behavior:

1. mkdir test
2. cd test
3. rmdir test in another shell
4. no prompt at all in first shell

a different use case:

1. su - # switches to /root
2. su # changes user but cwd will be /root with usually no permissions
3. no prompt at all

Expected behavior
a working prompt with the "no permission" char

Environment (please complete the following information):

• OS: linux
• Architecture: amd64
• Shell: zsh