[Rd] substitute creates an object which prints incorrectly (PR#9427)

[Bill.Venables at csiro.au]

Bill.Venables at csiro.au (i.e. I) wrote:

> 3. Modify substitute() so that it strips source attributes (or
anything
> else apparently visible that it will not manipulate) from objects.
> Sorry folks, too dangerous.  (I concede this appears to be a bit of an
> overkill, too.)

Peter Dalgaard responded:
  
Actually, this is the easier fix to my mind. Where do you see the
danger?

To which I reply:

Well, if it's feasible, I'd recommend this as the way to go.  My
detached 
phrase "Sorry folks, too dangerous" was simply my wondering how we might

field the inevitable howls of protest when people find that something
has 
changed.  I know people will notice since this is a glych I spotted when

trying to debug someone else's code, but that person, at least, will 
applaud I'm sure.

In short, I don't think there are any real dangers.  I just thought it 
would slow things down too much, but perhaps not.

Bill Venables.