R devel - Feb 2021 - surprised matrix (1:256, 8, 8) doesn't cause error/warning

I'm a little surprised that the following doesn't trigger an error or a
warning.

matrix (1:256, 8, 8)

The help file says that the main argument is recycled, if it's too short.
But doesn't say what happens if it's too long.

>>>>> Abby Spurdle (/??bi/) 
>>>>>     on Mon, 1 Feb 2021 19:50:32 +1300 writes:
    > I'm a little surprised that the following doesn't trigger an
error or a warning.
    > matrix (1:256, 8, 8)

    > The help file says that the main argument is recycled, if it's too
short.
    > But doesn't say what happens if it's too long.

It's somewhat subtler than one may assume :
> matrix(1:9, 2,3)
     [,1] [,2] [,3]
[1,]    1    3    5
[2,]    2    4    6
Warning message:
In matrix(1:9, 2, 3) :
  data length [9] is not a sub-multiple or multiple of the number of rows [2]
> matrix(1:8, 2,3)
     [,1] [,2] [,3]
[1,]    1    3    5
[2,]    2    4    6
Warning message:
In matrix(1:8, 2, 3) :
  data length [8] is not a sub-multiple or multiple of the number of columns [3]
> matrix(1:12, 2,3)
     [,1] [,2] [,3]
[1,]    1    3    5
[2,]    2    4    6
>
So it looks to me the current behavior is quite on purpose.
Are you sure it's not documented at all when reading the docs
carefully?  (I did *not*, just now).