[O] Error when editing src block

[Florian Beck]

When `org-edit-src-code' fails to load the language mode, it leaves the 
buffer(s) in an unusable state. For example, evaluate

M-: (add-hook 'emacs-lisp-mode-hook 'paredit-mode)

Then C-c ' in this block

#+begin_src emacs-lisp
  (save-excursion
#+end_src

 -> byte-code: Language mode `emacs-lisp-mode' fails with: "Unmatched 
bracket or quote"

That's fine. But now C-c ' doesn't work and M-x org-edit-src-exit claims:

org-edit-src-exit: This is not a sub-editing buffer, something is wrong

Indeed.

I guess, the source buffer and the overlay should be cleaned up. But 
since the worst that can happen is the language mode not loading 
correctly, maybe just downgrade the error to a warning?


--
Florian Beck