[Rd] is.finite confusion

[Vladimir Dergachev]

    I have recently made a silly screwup by applying is.finite() to a 
character vector:

>  is.finite(c("a", "b"))
[1] FALSE FALSE

This does work with factors of course (as they are integer underneath)

I wonder if a fix could be put in so that it either reports an error when 
applied to a character vector - or, perhaps better, act as is.na()

                      thank you

                               Vladimir Dergachev
PS test on R 2.5.0, 2.3.1