[O] minor bug in babel with silent output and remote R session

[Thomas Alexander Gerds]

Using the silent option together with a remote R session block (started
via ssh.el and ess-remote), like this:

#+BEGIN_SRC R  :results silent :exports results  :session *ssh gauss* :cache 
yes 
a=1
1
#+END_SRC

produces:

,----
| > > > [1] 1
| > Warning message:
| In file.rename(tfile, transfer.file) :
|   cannot rename file '/tmp/RtmpQwlyCf/file7c9b78867f6c' to 
'/tmp/babel-4977UIT/R-4977ucf', reason 'No such file or directory'
| > 
`----

and emacs freezes. No big deal because C-g gets me out of it, but
slightly annoying.  

with `:results output' instead of `:results: silent' everything works
fine.


best,
Thomas