improved pairs.formula?

Dear all,

I would like to suggest changing the pairs.formula command such that a
command like

       pairs(GNP ~ . - Year - GNP.deflator, longley)

would behave in a similar fashion as

       lm(GNP ~ . - Year - GNP.deflator, longley)

i.e., make a pairwise scatterplot of GNP and all other variables in
the (longley) dataframe except for Year and GNP.deflator.  The above
command, with the current version of pairs.formula, produces a
pairwise scatterplot of all variables in the (longley) dataframe.

After some tinkering around, I came up with the following replacement
function of pairs.formula which seems to do the job:

   pairs.formula <-
   function (formula, data = NULL, ..., subset, na.action = stats::na.pass)
   {
     m <- match.call(expand.dots = FALSE)
     if (is.matrix(eval(m$data, parent.frame())))
       m$data <- as.data.frame(data)
     m$... <- NULL
     m$na.action <- stats::na.pass
     m[[1]] <- as.name("model.frame")
     mf <- eval(m, parent.frame())

     mt <- attr(mf, "terms")
     tmp <- attr(mt, "factors")
     ind <- apply(tmp, 1, max)
     sv <- rownames(tmp)[ind>0]
     ind <- match(sv,
                  sapply(attr(mt, "variables"), deparse, width.cutoff=500)[-1])
     if( (tt <- attr(mt, "response")) != 0 ){
       ind <- c(tt, ind)
     }

     pairs(mf[,ind], ...)
   }

Would you please kindly consider replacing the current pairs.formula
function (at the top of the file src/library/graphics/R/pairs.R) with
the above function?