commit e446fbd5c32c16e0a7bc8bd600b4582e20bb7a4f
author Todd Wang <toddw@google.com> Mon Jan 04 17:27:21 2016 -0800
committer Todd Wang <toddw@google.com> Mon Jan 04 17:27:34 2016 -0800
tree 9801aeedf1ea515ae4757b8a4e580d51ea21547d
parent 4cd09def81b465086add5eedc3185dd5e7376d4c

lib: 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: 1/2

Change-Id: I77d04a1bc90f1b07fe4d0f8815a963f4fb73739e