[Rd] R CMD check does not report redundant '...' argument described in Rd File

[Georgi Boshnakov]

R's checks seem to be failing to notice a redundant '...' argument described in the documentation of a function.

Consider a function:

fun_3 <- function(arg1, arg2, arg3) {
    "I am fun_3"
}

If its documentation describes an argument, say 'dummy', R check reports something like:

* checking Rd \usage sections ... WARNING
Documented arguments not in \usage in documentation object 'fun_3b':
  'dummy'
...

But if the non-existent argument is '...' or '\dots' there is no warning. The omission seems specific to the 'dots' argument. 

Checked under Windows on win-builder on 17 April 2018 with
R version 3.6.0 beta (2019-04-16 r76403), R version 3.5.3 (2019-03-11) and
R version 3.4.4 (2018-03-15).

A minimal package illustrating this is at 
https://github.com/GeoBosh/reprexes/tree/master/redundantDots


Georgi Boshnakov