From: Daniel Martín <mardani29@yahoo.es>
Date: Tue, 15 Sep 2020 12:56:10 +0000 (+0200)
Subject: Check that the buffer in diff-buffer-with-file is visiting a file
X-Git-Tag: emacs-28.0.90~6061
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=d727d3dad649d1569a6babaf398439d101e282d4;p=emacs.git

Check that the buffer in diff-buffer-with-file is visiting a file

* lisp/vc/diff.el (diff-buffer-with-file): Signal a specific error
when the buffer passed to diff-buffer-with-file is not visiting a
file (bug#43401).
---

diff --git a/lisp/vc/diff.el b/lisp/vc/diff.el
index 469888078c4..b7f17bf3c73 100644
--- a/lisp/vc/diff.el
+++ b/lisp/vc/diff.el
@@ -258,6 +258,8 @@ This requires the external program `diff' to be in your `exec-path'."
   (interactive "bBuffer: ")
   (let ((buf (get-buffer (or buffer (current-buffer)))))
     (with-current-buffer (or (buffer-base-buffer buf) buf)
+      (unless buffer-file-name
+        (error "Buffer is not visiting a file"))
       (diff buffer-file-name (current-buffer) nil 'noasync))))
 
 ;;;###autoload