Prevent mv from moving target folder

In zsh, as long as you don't unsetopt auto_remove_slash, zsh removes the trailing slash at the end of completion. It adds a slash during completion, so that baTab results in bar/, but if you press Space (or move the cursor or most anything other than inserting something), zsh removes the /. (The / is highlighted to indicate that it's “on sufferance”.)

If you end up entering the command with a slash mv bar/ baz, renaming the directory foo is the expected behavior. Since bar/ ends with a slash, pathname resolution converts it to foo.

If you want to avoid this behavior, you'll have to write a wrapper function for mv. Untested, for zsh:

function mv {
  local i
  for ((i=1; i < $#; i++)); do
    if [[ $argv[$i] == *[^/]*/ ]]; then
      argv[$i]=${argv[i]%/}
    fi
  done
  command mv "$@"
}

Note that this function is fairly naive, for example it doesn't understand that -t/--target takes a destination as argument which shouldn't have its trailing slash stripped.