Variable: buffer-file-numbers-unique
buffer-file-numbers-unique is a variable defined in files.el.gz.
Value
t
Documentation
Non-nil means that buffer-file-number uniquely identifies files.
Source Code
;; Defined in /usr/src/emacs/lisp/files.el.gz
(defvar buffer-file-numbers-unique (not (memq system-type '(windows-nt)))
"Non-nil means that `buffer-file-number' uniquely identifies files.")