(diff): Simplify code handling `switch'.

1 files changed, 3 insertions, 8 deletions

diff --git a/lisp/diff.el b/lisp/diff.el
index dab3c7ebff3..01b9e590a07 100644
--- a/lisp/diff.el
+++ b/lisp/diff.el
@@ -220,7 +220,8 @@ With prefix arg, prompt for diff switches."
      (list oldf newf (diff-switches))))
   (setq new (expand-file-name new)
         old (expand-file-name old))
-  (let ((old-alt (file-local-copy old))
+  (or switches (setq switches diff-switches)) ; If not specified, use default.
+  (let* ((old-alt (file-local-copy old))
         (new-alt (file-local-copy new))
         buf)
     (save-excursion
@@ -229,13 +230,7 @@ With prefix arg, prompt for diff switches."
                (mapconcat 'identity
                           `(,diff-command
                             ;; Use explicitly specified switches
-                            ,@(if switches
-                                  (if (listp switches)
-                                      switches (list switches))
-                                ;; If not specified, use default.
-                                (if (listp diff-switches)
-                                    diff-switches
-                                  (list diff-switches)))
+                            ,@(if (listp switches) switches (list switches))
                             ,@(if (or old-alt new-alt)
                                   (list "-L" old "-L" new))
                             ,(shell-quote-argument (or old-alt old))