Odd outcome of attr with environments (PR#2148)

Hi everyone,

I think the following error is slightly odd:

fred <- new.env()
happy <- function() fred
happy()

<environment: 0x8a425b8>

attr(happy(), "foo") <- 1:10

Error: invalid (NULL) left side of assignment

But naturally this works

attr(fred, "foo") <- 1:10
fred

<environment: 0x8a425b8>
attr(,"foo")
 [1]  1  2  3  4  5  6  7  8  9 10

I would have thought that "fred" and "happy()" were synonymous, so I
was surprised that I could not attach an attribute to the environment
using "happy()".  Of course in practice I can get round this by doing

sad <- happy()
attr(sad, "foo") <- 5:1
sad

<environment: 0x8a425b8>
attr(,"foo")
[1] 5 4 3 2 1

happy()

<environment: 0x8a425b8>
attr(,"foo")
[1] 5 4 3 2 1

but I wondered what was going on.

Cheers, Jonathan.

--please do not edit the information below--

Version:
 platform = i686-pc-linux-gnu
 arch = i686
 os = linux-gnu
 system = i686, linux-gnu
 status = 
 major = 1
 minor = 6.0
 year = 2002
 month = 10
 day = 01
 language = R

Search Path:
 .GlobalEnv, Autoloads, package:base

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