It is not possible to use a Conn in ForkExec or Dup or Dup2

[rminnich]

File is used in Dup* and ForkExec. Conn is used to create connections, either pipes, UDP
connections, TCP connections, and so on. There is a disconnect between these constructs.
It should be possible to substitute a Conn in many places where a File is used, e.g. in
Dup or ForkExec; it currently is not. I have suggested a simple patch in 1711047, but
this change is somewhat unsatisfying because the Pipe type has four fds; which one of
these should be used. 

Also, even should 1711047 be accepted, there is a further problem, detailed in the same
patch, with the use of shutdown(): even if the File for a Conn is available via Dup or
ForkExec, the shutdown will blow the underlying connection away. 

What steps will reproduce the problem?
1.Try to user a Conn with ForkExec or Dup or Dup2

I'm not sure the rest of these questions are relevant. It's a design issue not related
to any particular version of Go. 

What is the expected output?


What do you see instead?


What is your $GOOS?  $GOARCH?


Which revision are you using?  (hg identify)


Please provide any additional information below.

[adg]

Comment 1:

Labels changed: added priority-low, packagechange, removed priority-medium.

Owner changed to [email protected].

Status changed to Thinking.

[rsc]

Comment 2:

Issue #1154 has been merged into this issue.

[rsc]

Comment 3:

This issue was closed by revision a144e3e.

Status changed to Fixed.