Comment 6 for bug 312449

slangasek once said:
"the reasons for not regenerating the config file whenever it's missing or empty are rooted in the Debian and Ubuntu policy on config files, and this can't be changed without causing more problems than it solves."

so we should rather have a more informative error message. Something like:
Not replacing deleted config file /etc/samba/smb.conf
Install/upgrade will fail. To recover, please try:
  sudo cp /usr/share/samba/smb.conf /etc/samba/smb.conf
  sudo dpkg --configure -a