[Rd] Second X11 call with invalid display crashes R after first X11 call. (PR#12628)

[b.rowlingson at lancaster.ac.uk]

I get this with R 2.7.2 (and 2.7.1, and 2.6.2, but NOT 2.4.0):

 > X11() # this one opens up okay
 > X11("foo")
 Error: Couldn't find per display information
 $

and R crashes out back to my shell prompt.

If I do X11("foo") as a first command I get a meaningful error and my
R prompt back:

> X11("foo")
Error in X11(d$display, d$width, d$height, d$pointsize, d$gamma, d$colortype,  :

  unable to start device X11cairo
In addition: Warning message:
In X11("foo") : unable to open connection to X11 display 'foo'
>

So it only seems to be after a *successful* X11() call it that it crashes R.

Can't find anything in latest changes that refer to fixing this.

My system is Ubuntu 7.10 with R 2.7.2 from latest repository, also
happens with an R 2.7.0 binary I've got hanging around compiled from
source and also happens on other systems I've tried.

> sessionInfo()
R version 2.7.2 (2008-08-25)
i486-pc-linux-gnu

locale:
LC_CTYPE=en_GB.UTF-8;LC_NUMERIC=C;LC_TIME=en_GB.UTF-8;LC_COLLATE=en_GB.UTF-8;LC_
MONETARY=C;LC_MESSAGES=en_GB.UTF-8;LC_PAPER=en_GB.UTF-8;LC_NAME=C;LC_ADDRESS=C;L
C_TELEPHONE=C;LC_MEASUREMENT=en_GB.UTF-8;LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base