(find-buffer-visiting): Don't check buffer-file-number

unless buffer-file-name is non-nil.

1 files changed, 2 insertions, 1 deletions

diff --git a/lisp/files.el b/lisp/files.el
index 2b3590176f3..f36dc409e46 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -596,7 +596,8 @@ If there is no such live buffer, return nil."
                (while (and (not found) list)
                  (save-excursion
                    (set-buffer (car list))
-                   (if (and (equal buffer-file-number number)
+                   (if (and buffer-file-name
+                            (equal buffer-file-number number)
                             ;; Verify this buffer's file number
                             ;; still belongs to its file.
                             (file-exists-p buffer-file-name)