[ESS-bugs] new bug: Sweave not connecting to R correctly: value of `ess-dialect' is nil

[Martin Maechler]

This is somewhat related to my other (yet unreplied to) bug
report (Sun, 30 Sep 2012 20:40:48 +0200).

but this one is easily reproducible:

emacs  <file>.Rnw

In the Rnw file,  'M-n s'  (= M-x ess-swv-weave),
then, ESS
- sees that there's no R process, 
- ask for the directory where to start it,
- starts it,

but *THEN* fails with
    "No ESS process is associated with this buffer now"

If you try  'M-n s'  again you get the infamous 
error message 
      "Local value of `ess-dialect' is nil"

and that's why this bug is related to the other bug I reported
on Sunday.

Here's an excerpt from the *Messages* buffer :

---------------------------------------------------
.........................
Setting up syntax table
noweb-font-lock mode: use `M-x noweb-font-lock-describe-mode' for more info
Applying style hooks... done
no ESS processes running; starting R
Type C-h m for help on ESS version 12.09-mod
get-ess-process: No ESS process is associated with this buffer now
...
ess-request-a-process: Local value of `ess-dialect' is nil
---------------------------------------------------

The collegue who sent me the bug report was quite frustrated and
alarmed but then found a workaround:

Go inside one of the code (i.e. 'R') chunks, and press  
C-c C-n (= ess-eval-line-and-step).
This correctly sends to the *R* process started (above),
and now you can also use  'M-n s'

I'm sure this is not hard to fix.. but I'm extremely busy today
and tomorrow, as I'll go to a small (political)
symposium/meeting Thursday/Friday and then off to the Black
forest for a week of vacation, and we are in semester, so I
really am juggling with (too) many balls currently.

This bug is really a bit embarrassing, mostly toward the (many) *.Rnw
users (and the fact, I again reiterate that our biggest
competition, Rstudio, nowadays excells with Sweave support), 
so I propose a patch release, that I'd want to call '12.09-1'
a few days after I'm back from Germany,
a date around October 16, 17 or so.

This means that we should still fix small bugs, add small
features, but *not* start a major rewrite (eg. of noweb)
in the SVN trunk, till then. If you want to, either create an
svn branch, or a git one, or restrain till after release of 12.09-1.