using tcltk in R under ESS/XEmacs on Windows

[Liaw, Andy]

Sorry for the cross-post.  Not sure where the problem is...

A while back I posted an R function to R-help:

cd <- function (dir = tclvalue(tkchooseDirectory()), saveOld = FALSE, 
    loadNew = TRUE) {
    stopifnot(require(tcltk))
    if (saveOld) 
        save.image(compress = TRUE)
    setwd(dir)
    rm(list = ls(all = TRUE, envir = .GlobalEnv), envir = .GlobalEnv)
    if (loadNew && file.exists(".RData")) {
        loaded <- load(".RData", envir = .GlobalEnv)
        return(invisible(loaded))
    }

where the default value for the `dir' argument is to run the tcltk directory
chooser and get the directory name chosen.  (Thanks to Prof. John Fox for
the tcltk part!!)  While this function works fine under Rgui on Windows, it
doesn't work when running R within ESS (5.2.3) and XEmacs (21.4.13).  The
directory chooser never shows up, and dir just gets the empty string.  Does
anyone have any idea what could be the problem?  I'd very much appreciate
any pointers.

Best,
Andy