+ ((or
+ (file-exists-p target)
+ ;; If TARGET does not exist as a file, replace its
+ ;; base name with TARGET-BUF and try again. This
+ ;; is for jka-compr's sake, which strips the
+ ;; compression (.gz etc.) extension from the
+ ;; FILENAME, but leaves it in the BUFFER's name.
+ (and (stringp target-buf)
+ (file-exists-p
+ (expand-file-name target-buf
+ (file-name-directory target)))))