> buffer-modified-p is not the only parameter affected by juggling around
> the local variables. There will be undo history,
> buffer-chars-modified-tick, before/after-change-hooks triggered by
> `org-preserve-local-variables', etc.
>
> However, I do not see any obvious way how your proposed change can
> negatively affect all the above. Feel free to propose a patch.
I've written a patch proposal. It deals with buffer-modified-p and undo
history, but not the other two points you mention. I have tested it and
it works, but I had never dealt before with `buffer-undo-list' so maybe
there are some cases that I have not considered and for which this patch
could be problematic. Let me know what you think:
>From 14506bea13bf6278d95825257d90bbc3390ae8f1 Mon Sep 17 00:00:00 2001
From: Ignacio Casso <ignacioca...@hotmail.com>
Date: Sun, 12 Jun 2022 10:38:53 +0200
Subject: [PATCH] Do not mark buffer as modified with
org-preserve-local-variables
* lisp/org-macs.el (org-preserve-local-variables): Do not mark buffer
as modified or alter `buffer-undo-list' when body does not actually
modify the buffer.
This commit fixes a bug with `org-copy-subtree', which marked the
buffer as modified and added an entry to the undo list when the visited
file had local variables.
---
lisp/org-macs.el | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/lisp/org-macs.el b/lisp/org-macs.el
index 19e5f42e9..64beeff53 100644
--- a/lisp/org-macs.el
+++ b/lisp/org-macs.el
@@ -163,16 +163,24 @@
(org-with-wide-buffer
(goto-char (point-max))
(let ((case-fold-search t))
- (and (re-search-backward "^[ \t]*# +Local Variables:"
+ (when (re-search-backward "^[ \t]*# +Local Variables:"
(max (- (point) 3000) 1)
t)
- (delete-and-extract-region (point) (point-max)))))))
+ (undo-boundary)
+ (delete-and-extract-region (point) (point-max))))))
+ (tick-counter (buffer-modified-tick))
+ modified)
(unwind-protect (progn ,@body)
(when local-variables
+ (setq modified (< tick-counter (buffer-modified-tick)))
(org-with-wide-buffer
(goto-char (point-max))
(unless (bolp) (insert "\n"))
- (insert local-variables))))))
+ (insert local-variables))
+ (unless modified
+ (set-buffer-modified-p nil)
+ (setq buffer-undo-list
+ (seq-drop-while 'identity buffer-undo-list)))))))
(defmacro org-no-popups (&rest body)
"Suppress popup windows and evaluate BODY."
--
2.25.1
