Don’t create unnecessary marker in ‘delete-trailing-whitespace’

* lisp/simple.el (delete-trailing-whitespace): If END argument is nil,
there is no need for the end-marker to be created.

1 files changed, 9 insertions, 10 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index 37f6d5000e9..ba026aff77f 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -602,7 +602,7 @@ buffer if the variable `delete-trailing-lines' is non-nil."
                    (list nil nil))))
   (save-match-data
     (save-excursion
-      (let ((end-marker (copy-marker (or end (point-max)))))
+      (let ((end-marker (and end (copy-marker end))))
         (goto-char (or start (point-min)))
         (with-syntax-table (make-syntax-table (syntax-table))
           ;; Don't delete formfeeds, even if they are considered whitespace.
@@ -611,15 +611,14 @@ buffer if the variable `delete-trailing-lines' is non-nil."
           (modify-syntax-entry ?\n "_")
           (while (re-search-forward "\\s-+$" end-marker t)
             (delete-region (match-beginning 0) (match-end 0))))
-        ;; Delete trailing empty lines.
-        (goto-char end-marker)
-        (when (and (not end)
-                   delete-trailing-lines
-                   ;; Really the end of buffer.
-                   (= (point-max) (1+ (buffer-size)))
-                   (<= (skip-chars-backward "\n") -2))
-          (delete-region (1+ (point)) end-marker))
-        (set-marker end-marker nil))))
+        (if end
+            (set-marker end-marker nil)
+          ;; Delete trailing empty lines.
+          (and delete-trailing-lines
+               ;; Really the end of buffer.
+               (= (goto-char (point-max)) (1+ (buffer-size)))
+               (<= (skip-chars-backward "\n") -2)
+               (delete-region (1+ (point)) (point-max)))))))
   ;; Return nil for the benefit of `write-file-functions'.
   nil)