net/http: Response.Write should write Content-Length: 0 header if present and not chunked

[gopherbot]

by islandberry23:

I am filing this issue as requested at
https://groups.google.com/forum/#!topic/golang-nuts/8D_tno7WxaY

The transferWriter decides if it should write the content-length header at:
https://code.google.com/p/go/source/browse/src/pkg/net/http/transfer.go?name=release&;r=63dcf9ca33a74dec605f6156393d719150ad6e2e#116

This function returns false for a Content-Length: 0 response unless the transfer
encoding is explicitly set to identity.  

If a response has a content length header and the transfer encoding is not explicitly
set to chunked, then the content length header should be written to the output. This is
true even of the content length is zero. Zero is a valid response body size.

[bradfitz]

Comment 1:

Please provide an example program in this bug that behaves incorrectly.

Owner changed to @bradfitz.

Status changed to Accepted.

[gopherbot]

Comment 2 by islandberry23:

http://play.golang.org/p/VMPK1Sc2tk
The content length should be written in all cases.

[bradfitz]

Comment 3:

I don't think we can change this.  A Content-Length of zero is the zero value of that
field of a Response.  This would affect other users.
What is your actual problem?  Maybe there's an alternate fix in the http server.  I
suspect you're proposing the solution instead of describing the problem.

[gopherbot]

Comment 4 by islandberry23:

You can change this by adding a boolean field to note if the content length header was
set or not.
I filed this issue at the request of the people participating in the linked thread.
Please contact them to discuss the actual problem.

[bradfitz]

Comment 5:

[+hi wang, the original poster on this topic]

Status changed to WaitingForReply.

[ceh]

Comment 6:

Duplicate of issue #5381?

[bradfitz]

Comment 7:

Thanks.

Status changed to Duplicate.

Merged into issue #5381.