Ihor Radchenko <yantar92@posteo.net> writes:

>> I agree it's a problem -- if there are multiple blocks with the same
>> session but different ":dir" arguments, then a ":file" result of the
>> second block will be relative to the wrong :dir.
>>
>> This seems like a longstanding problem, and affects both async and
>> non-async session blocks.
>
> Maybe something like the attached?

Nice, that seems like the right way to do it.

I updated the patch for `org-babel-comint-async-filter' to follow the
same approach, setting default-directory based on the session buffer's
value rather than the :dir header arg.