Function: diff-delete-trailing-whitespace

diff-delete-trailing-whitespace is an interactive and byte-compiled function defined in diff-mode.el.gz.

Signature

(diff-delete-trailing-whitespace &optional OTHER-FILE)

Documentation

Remove trailing whitespace from lines modified in this diff.

This edits both the current Diff mode buffer and the patched source file(s). If diff-jump-to-old-file is non-nil, edit the original (unpatched) source file instead. With a prefix argument OTHER-FILE, flip the choice of which source file to edit.

If a file referenced in the diff has no buffer and needs to be fixed, visit it in a buffer.

View in manual

Probably introduced at or before Emacs version 24.3.

Key Bindings

Source Code

;; Defined in /usr/src/emacs/lisp/vc/diff-mode.el.gz
(defun diff-delete-trailing-whitespace (&optional other-file)
  "Remove trailing whitespace from lines modified in this diff.
This edits both the current Diff mode buffer and the patched
source file(s).  If `diff-jump-to-old-file' is non-nil, edit the
original (unpatched) source file instead.  With a prefix argument
OTHER-FILE, flip the choice of which source file to edit.

If a file referenced in the diff has no buffer and needs to be
fixed, visit it in a buffer."
  (interactive "P")
  (save-excursion
    (goto-char (point-min))
    (let* ((other (xor other-file diff-jump-to-old-file))
           (modified-buffers nil)
           (style (save-excursion
                    (when (re-search-forward diff-hunk-header-re nil t)
                      (goto-char (match-beginning 0))
                      (diff-hunk-style))))
           (regexp (concat "^[" (if other "-<" "+>") "!]"
                           (if (eq style 'context) " " "")
                           ".*?\\([ \t]+\\)$"))
	   (inhibit-read-only t)
	   (end-marker (make-marker))
	   hunk-end)
      ;; Move to the first hunk.
      (re-search-forward diff-hunk-header-re nil 1)
      (while (progn (save-excursion
		      (re-search-forward diff-hunk-header-re nil 1)
		      (setq hunk-end (point)))
		    (< (point) hunk-end))
	;; For context diffs, search only in the appropriate half of
	;; the hunk.  For other diffs, search within the entire hunk.
        (if (not (eq style 'context))
            (set-marker end-marker hunk-end)
          (let ((mid-hunk
                 (save-excursion
                   (re-search-forward diff-context-mid-hunk-header-re hunk-end)
                   (point))))
            (if other
                (set-marker end-marker mid-hunk)
              (goto-char mid-hunk)
              (set-marker end-marker hunk-end))))
	(while (re-search-forward regexp end-marker t)
	  (let ((match-data (match-data)))
	    (pcase-let ((`(,buf ,line-offset ,pos ,src ,_dst ,_switched)
			 (diff-find-source-location other-file)))
	      (when line-offset
		;; Remove the whitespace in the Diff mode buffer.
		(set-match-data match-data)
		(replace-match "" t t nil 1)
		;; Remove the whitespace in the source buffer.
		(with-current-buffer buf
		  (save-excursion
		    (goto-char (+ (car pos) (cdr src)))
		    (beginning-of-line)
		    (when (re-search-forward "\\([ \t]+\\)$" (line-end-position) t)
		      (unless (memq buf modified-buffers)
			(push buf modified-buffers))
		      (replace-match ""))))))))
	(goto-char hunk-end))
      (if modified-buffers
	  (message "Deleted trailing whitespace from %s."
		   (mapconcat (lambda (buf) (format-message
					     "`%s'" (buffer-name buf)))
			      modified-buffers ", "))
	(message "No trailing whitespace to delete.")))))