bug#4673: Not the same as 4674

[Richard Copley]

This is a separate bug from 4673 (which I believe is fixed). Can they
be un-merged?

Visiting a Windows DFS share when ".." is not accessible still crashes
in `ls-lisp-insert-directory' in the trunk of Emacs, as the attribute
list for ".." in the `file-alist' returned for by
`directory-files-and-attributes' is empty.

Namely, (directory-files-and-attributes "//root/share" nil nil t
'string) returns something like this:

   '(("." t 1 "RCO" "Domain Users" (20263 19364) (20263 19364) (18713
25576) 0 "drwxrwxrwx" nil 0 (18463 . 35684))
     ("..")
     ("file 1.csv" nil 1 "RCO" "Domain Users" (18744 6249) (18713
32060) (18713 25866) 13008 "-rw-rw-rw-" nil 0 (18463 . 35684))
     ("file 2.csv" nil 1 "RCO" "Domain Users" (20043 4789) (20043
4789) (20043 4789) 19134 "-rw-rw-rw-" nil 0 (18463 . 35684))
     ("file 3.csv" nil 1 "RCO" "Domain Users" (18788 55198) (20263
52634) (18788 55198) 29596 "-rw-rw-rw-" nil 0 (18463 . 35684))))

Meanwhile, back in `ls-lisp-insert-directory', (format "%d" fuid)
fails with (error "Format specifier doesn't match argument type").