[Orgmode] Coding systems in Babel

[Vincent Beffara]

Hi, it's me again, still trying to make sense of the interaction between
Org, Babel and coding systems. I have, in a UTF8-encoded .org file, this
code block:

--8<---------------cut here---------------start------------->8---
#+tblname: toto
| é |

#+begin_src python :var t=toto :preamble # -*- coding: latin1 -*-
babel = unicode (t[0][0],"latin1")
local = unicode ("é","latin1")
return [len(babel), len(local)]
#+end_src
--8<---------------cut here---------------end--------------->8---

Evaluating the block with C-c C-c leads to this:

--8<---------------cut here---------------start------------->8---
#+results:
| 1 | 1 |
--8<---------------cut here---------------end--------------->8---

So, the instance of python spawned by C-c C-c receives the text as
latin-1 encoded. Somewhere a conversion from UTF8 to latin-1
happens. But I don't want that, I want everything to stay in UTF8 from
the beginning to the end. I guess I have two questions:

At what point in the process is the convertion performed ?

How do I prevent it / how do I specify UTF8 as the exchange format
between Org-Babel and outside processes spawned by C-c C-c ?

The whole point is to make executed code-blocks and tangled source code
behave the same way - in that particular case, tangling leads to a
UTF8-encoded file, which is what I expected to happen.

Thanks for your help!

       /vincent