(buffer-file-numbers-unique): New variable;

initialize to nil for windows-nt.
(find-buffer-visiting): Skip search for buffer based
on buffer-file-number if these are not unique.

diff --git a/lisp/files.el b/lisp/files.el
index eb2b3ed9c9d6c86ceabd9018979fb80122de0577..7a3bb717c2a4dad8b7b30a5f60ebc1bffb26a8d4 100644 (file)
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -123,6 +123,9 @@ If the buffer is visiting a new file, the value is nil.")
 (make-variable-buffer-local 'buffer-file-number)
 (put 'buffer-file-number 'permanent-local t)
 
+(defvar buffer-file-numbers-unique (not (memq system-type '(windows-nt)))
+  "Non-nil means that buffer-file-number uniquely identifies files.")
+
 (defconst file-precious-flag nil
   "*Non-nil means protect against I/O errors while saving files.
 Some modes set this non-nil in particular buffers.
@@ -691,7 +694,8 @@ If there is no such live buffer, return nil."
          found)
        (let ((number (nthcdr 10 (file-attributes truename)))
              (list (buffer-list)) found)
-         (and number
+         (and buffer-file-numbers-unique
+              number
               (while (and (not found) list)
                 (save-excursion
                   (set-buffer (car list))