On 03.01.2024 16:11, Ihor Radchenko wrote:
> gerard.vermeulen@posteo.net writes:
> 
[...]
Attached you'll find a new patch that seems to solve the block 
indentation
problem that you have pointed out, see PS or attached patch-demo.org.

test-ob/demarcate-block-split passes.
> 
> This was a bug in `org-element-copy'. Fixed, on main now.
> https://git.savannah.gnu.org/cgit/emacs/org-mode.git/commit/?id=dfeff03c5
> 
I did not yet pull your change.  Nevertheless, the Emergency exit errors
have disappeared.
> 
[...]
> 
> I made some adjustments to the patch, making use of org-element API.
> See the attached updated version of the patch.
> 
This patch is heavily edited and I think I did not forget any of your 
changes.

I have tried to clean up the code.  I have also tried to get `body-beg' 
and
`body-end' marking the text between the #+begin_src and #+end_src lines
from the element API, but I failed and had to fall back to
`org-babel-where-is-src-block-head'.  But only for that.

> I am not yet merging it as I found some weirdness with indentation.
> Consider the following (indentation is important):
> 
>             #+BEGIN_SRC emacs-lisp -n 20
>               ;; This exports with line number 20.
> <point>       (message "This is line 21")
>             #+END_SRC
> 
> After M-x org-babel-demarcate-block, I am getting
> 
>             #+BEGIN_SRC emacs-lisp -n 20
>               ;; This exports with line number 20.
>               #+END_SRC
> 
> #+begin_src emacs-lisp -n 20
>   (message "This is line 21")
> #+end_src
See PS or patch-demo.org: PS (hope you read it with a mono-spaced font):
#+begin_src emacs-lisp :results silent
   (setopt org-adapt-indentation t
           org-src-preserve-indentation nil
           org-edit-src-content-indentation 2)
#+end_src

******** before C-u org-babel-demarcate-block splitting

          I put point at the left of the last line in this block before 
splitting
          #+BEGIN_SRC emacs-lisp -n 20
            ;; this exports with line number 20
<point>    (message "This exports with line number 21")
          #+END_SRC
          C-u C-c C-v d gets the stars right and the indentation

******** after C-u org-babel-demarcate-block splitting

          I put point at the left of the last line in this block before 
splitting
          #+begin_src emacs-lisp -n 20
            ;; this exports with line number 20
          #+end_src
********
          #+begin_src emacs-lisp -n 20
            (message "This exports with line number 21")
          #+end_src
          C-u C-c C-v d gets the stars right and the indentation