commit 0997ad001e19acf1be613b3f75a47f94ab554efa
author Todd Wang <toddw@google.com> Tue Dec 29 11:23:20 2015 -0800
committer Todd Wang <toddw@google.com> Tue Dec 29 11:23:20 2015 -0800
tree 192fc75e38b40e3e74e781145bb56a145f2a6223
parent 57dd739835226800380d02641a23d1d203e704ac

ref: Change gosh.Cmd.AddStdoutWriter to take an io.WriteCloser

The rationale behind this change is detailed here:
https://github.com/vanadium/issues/issues/1031

The basic idea is that the previous gosh behavior wrt
Cmd.AddStdoutWriter (and AddStderrWriter) was a bit weird.  We
took an io.Writer argument w, and if w happened to implement
io.Closer, we'd auto-close w when the process finished.  The
semantics of Close is largely implementation-dependent, which
made the gosh usage a bit scary.  In addition we special-cased
os.Stdout and os.Stderr, to prevent closing those when a single
cmd finished.

This change makes things more explicit.  We always take an
io.WriteCloser as an argument, which we will auto-close when the
process finishes.  We also remove the os.Stdout and os.Stderr
special-cases, and add gosh.NopWriteCloser instead.

MultiPart: 2/2

Change-Id: Iefd67aef7f9d5beab1786adadcc423fdbf2d8fd2