(For records, below is the original patch, sent off-list)

> From 1523056a0dff5de64ed361d5bb1ad7d92ec7e369 Mon Sep 17 00:00:00 2001
> From: Olivier Lischer <olivier.lischer@liolin.ch>
> Date: Tue, 23 Jan 2024 21:02:20 +0100
> Subject: [PATCH] ob-tangle: Add flag to optionally remove files before writing
>
> * lisp/ob-tangle.el: Add variable
> `org-babel-tangle-remove-file-before-write'.
> (org-babel-tangle): Remove file before writing when
> `org-babel-tangle-remove-file-before-write' is set.
>
> The variable `org-babel-tangle-remove-file-before-write' adds support
> for the current and old behaviour of `org-babel-tangle'.
>
> TINYCHANGE
> ---
>  etc/ORG-NEWS      |  4 ++++
>  lisp/ob-tangle.el | 15 +++++++++++++--
>  2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
> index f537486d4..c7c3ee264 100644
> --- a/etc/ORG-NEWS
> +++ b/etc/ORG-NEWS
> @@ -800,6 +800,10 @@ Completion is enabled for links to man pages added using ~org-insert-link~:
>  =C-c C-l man RET emacscl TAB= to get =emacsclient=.  Of course, the ~ol-man~
>  library should be loaded first.
>  
> +*** =ob-tangle.el=: Add flag to optionally remove files before writing
> +
> +When ~org-babel-tangle-remove-file-before-write~ is set to ~t~ the file is removed before writing.
> +
>  ** New functions and changes in function arguments
>  *** New API functions to store data within ~org-element-cache~
>  
> diff --git a/lisp/ob-tangle.el b/lisp/ob-tangle.el
> index 72089a9a5..b77a19d3b 100644
> --- a/lisp/ob-tangle.el
> +++ b/lisp/ob-tangle.el
> @@ -141,7 +141,7 @@ controlled by the :comments header argument."
>    :version "24.1"
>    :type 'string)
>  
> -(defcustom org-babel-tangle-uncomment-comments nil
> +(defcustom org-babel-tangle-uncomment-comments 'auto
>    "Inhibits automatic commenting and addition of trailing newline
>  of tangle comments.  Use `org-babel-tangle-comment-format-beg'
>  and `org-babel-tangle-comment-format-end' to customize the format
> @@ -166,6 +166,12 @@ read-write permissions for the user, read-only for everyone else."
>    :package-version '(Org . "9.6")
>    :type 'integer)
>  
> +(defcustom org-babel-tangle-remove-file-before-write 'auto
> +  "Prevents the deletion of an existing file before tangle"
> +  :group 'org-babel-tangle
> +  :package-version '(Org . "9.7")
> +  :type 'boolean)
> +
>  (defun org-babel-find-file-noselect-refresh (file)
>    "Find file ensuring that the latest changes on disk are
>  represented in the file."
> @@ -315,7 +321,12 @@ matching a regular expression."
>                                         tangle-buf nil nil)))))))
>                       ;; We do not erase, but overwrite previous file
>                       ;; to preserve any existing symlinks.
> -		     (write-region nil nil file-name)
> +                     ;; This behavior can be changed using
> +                     ;; org-babel-tangle-remove-file-before-write
> +                     ;; to tangle to read-only files.
> +                     (when (and (file-exists-p file-name) (not (file-writeable-p file-name) org-babel-tangle-remove-file-before-write)
> +                       (delete-file file-name))
> +                     (write-region nil nil file-name)
>  		     (mapc (lambda (mode) (set-file-modes file-name mode)) modes))
>                     (push file-name path-collector))))))
>  	 (if (equal arg '(4))
> -- 
> 2.44.0
>

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>