What steps will reproduce the problem?

Run http://play.golang.org/p/SmkSnOoyAC locally. For reference, here is a sample
response from that http server:

HTTP/1.1 200 OK
Custom: a
Custom: b
Content-Type: text/plain; charset=utf-8
Content-Length: 0
Date: Sun, 28 Jul 2013 21:02:11 GMT


What is the expected output?

The documentation for http.Response reads: "If the response had multiple headers
with the same key, they will be concatenated, with comma delimiters.  (Section 4.2 of
RFC 2616 requires that multiple headers be semantically equivalent to a comma-delimited
sequence.)"

Given that, I'd expect to see "[a, b]" (a slice containing a single string,
"a, b").


What do you see instead?

"[a b]" (a slice containing two strings, "a" and "b").


Which compiler are you using (5g, 6g, 8g, gccgo)?

6g


Which operating system are you using?

OS X


Which version are you using?  (run 'go version')

1.1


Please provide any additional information below.

It is not obvious to me whether the behavior or the documentation should be changed.