[BUG]: unexpected behavior related to org-indent-block

[gerard . vermeulen]

Below, I show 2 commands to be run with point on a source block.
I expect that those commands modify an Org file identically, but
they do not.  It fails when `org-indent-block' is called in a
loop after each `(insert (org-element-interpret-data copy))' and
it works when `org-indent-block' is called in a separate loop
after insertion of all `(org-element-interpret-data copy)'s:

#+begin_src emacs-lisp :results silent
(defun make-2-indent-fails ()
  "Make 2 modified blocks, but fails."
  (interactive)
  (let ((copy (org-element-copy (org-element-at-point)))
        (n 0))
    (delete-region (org-element-begin copy) (org-element-end copy))
    (while (< n 2)
      (cl-incf n)
      (org-element-put-property copy :value (format "copy %s" n))
      (insert (org-element-interpret-data copy))
      (org-indent-block))))

(defun make-2-indent-works ()
  "Make 2 modified blocks, and works."
  (interactive)
  (let ((copy (org-element-copy (org-element-at-point)))
        (n 0))
    (delete-region (org-element-begin copy) (org-element-end copy))
    (while (< n 2)
      (cl-incf n)
      (org-element-put-property copy :value (format "copy %s" n))
      (insert (org-element-interpret-data copy)))
    (org-previous-block n)
    (while (> n 0)
      (cl-decf n)
      (org-indent-block))))
#+end_src

Example block:
---
#+begin_src emacs-lisp
<point>
#+end_src
---
make-2-indent-fails results in
---
#+begin_src emacs-lisp
copy 1
#+end_src
---
make-2-indent-works results in
---
#+begin_src emacs-lisp
copy 1
#+end_src
#+begin_src emacs-lisp
copy 2
#+end_src
---

I think that it is also weird that this bug does not show up in
this ERT test while it does outside ERT:
#+begin_src emacs-lisp :results silent
(ert-deftest test-make-2-indent-fails ()
  "Test unfolded `make-2-indent-fails'."
  (org-test-with-temp-text "
,#+begin_src emacs-lisp
<point>
,#+end_src
"
    (let ((copy (org-element-copy (org-element-at-point)))
          (word "copy")
          (n 0))
      (delete-region (org-element-begin copy) (org-element-end copy))
      (while (< n 2)
        (cl-incf n)
        (org-element-put-property copy :value (format "%s %s" word n))
        ;; Why does this work inside ERT and not outside ERT?
        (insert (org-element-interpret-data copy))
        (org-indent-block))
      (message "`%s'" (buffer-substring (point-min) (point-max)))
      (goto-char (point-min))
      (while (> n 0)
        (cl-decf n)
        (should (re-search-forward word)))
      (should-not (re-search-forward word nil 'noerror)))))
#+end_src

Regards -- Gerard