Calling M-x newline when in org src block. Turns it yellow and prevents
editing (it opens org edit src )

I have tried the latest emacs and org-mode. And run the following code
in an emacs -q

note: I changed the key-maps to include just ones available in default emacs


(defun setup-buf1 ()
  (with-current-buffer (get-buffer-create test-buffer-name)
    (erase-buffer)
    (insert "
  #+begin_src elisp :result output
    (setq a \"grass\")
  #+end_src
")
    (org-mode)))


(defun code-that-activates-bad-behaviour ()
  (interactive)
  (switch-to-buffer test-buffer-name)
  (goto-char (point-min))
  (save-excursion
    (search-forward "grass")
    (goto-char (point-at-eol))
    (call-interactively 'newline)
    (insert "h")
    (forward-sexp 1)))


(progn
  (add-to-list 'load-path "~/emacsd-main/el-get/org-mode/lisp")
  (require 'org)
  (setq test-buffer-name "my-test-buf")
  (setq org-src-preserve-indentation t)
  (setq org-src-window-setup 'current-window)
  (setq org-src-strip-leading-and-trailing-blank-lines t)
  (setq org-edit-src-content-indentation 2)
  (setq org-src-tab-acts-natively t))


(add-to-list 'load-path "~/emacs-config/dem/setup-dem/")


(defun org-src-edit-mode-setup ()
  (let* ((b (ignore-errors
     (current-buffer)))
(bufn (and b
   (buffer-name b))))
    (when (string-match "\\`*Org Src " bufn)

      (let ((mpk-map (copy-keymap org-mode-map))
   (qa-map (copy-keymap emacs-lisp-mode-map))
   (f-map (copy-keymap abbrev-map)))

(define-key mpk-map (kbd "o") qa-map)
(define-key qa-map (kbd "f") f-map)
(define-key f-map (kbd "s") 'find-file)

(define-key mpk-map  (kbd "s")  Info-mode-map)

(define-key org-src-mode-map (kbd "b") mpk-map)))))

(add-hook 'org-src-mode-hook 'org-src-edit-mode-setup)


(setup-buf1)
(code-that-activates-bad-behaviour)







In GNU Emacs 27.0.50 (build 4, x86_64-pc-linux-gnu, GTK+ Version 3.22.30,
cairo version 1.15.10)
 of 2019-07-02 built on Slug
Repository revision: b35f378d6e7d52393f1afc32a6f9880b9240af91
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description: Ubuntu 18.04.2 LTS

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Invalid image ‘:rotation’ parameter [10 times]
delete-backward-char: Text is read-only
Making completion list...
Loading
/home/dericbytes/emacs-config/dem/test-init/init-org-src-fix-test.el
(source)...done

Configured using:
 'configure --with-mailutils --with-xwidgets --with-cairo --with-modules
 --with-imagemagick'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO IMAGEMAGICK SOUND DBUS GSETTINGS GLIB
NOTIFY INOTIFY GNUTLS LIBXML2 FREETYPE HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS
GTK3 X11 XDBE XIM MODULES THREADS XWIDGETS PDUMPER LCMS2 GMP

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Load-path shadows:
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Memory information:
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