From 7a41dcb620f67b047d9ae167e64a593b1dcb4601 Mon Sep 17 00:00:00 2001
From: Juan Batiz-Benet <juan@benet.ai>
Date: Wed, 29 Jul 2015 01:18:04 -0700
Subject: [PATCH] updated goprocess (SetTeardown fix)

License: MIT
Signed-off-by: Juan Batiz-Benet <juan@benet.ai>
---
 Godeps/Godeps.json                            |  2 +-
 .../github.com/jbenet/goprocess/goprocess.go  |  2 --
 .../jbenet/goprocess/goprocess_test.go        |  2 --
 .../github.com/jbenet/goprocess/impl-mutex.go | 28 +++++++++----------
 4 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/Godeps/Godeps.json b/Godeps/Godeps.json
index 1797c4f88..d1663a336 100644
--- a/Godeps/Godeps.json
+++ b/Godeps/Godeps.json
@@ -204,7 +204,7 @@
 		},
 		{
 			"ImportPath": "github.com/jbenet/goprocess",
-			"Rev": "788dcf5ca3517f243d276394545ca6b3b4ac32d5"
+			"Rev": "4562d0c5780b8f060df2b84a8945bb8678bfc023"
 		},
 		{
 			"ImportPath": "github.com/kardianos/osext",
diff --git a/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess.go b/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess.go
index 17cb37799..b027d8214 100644
--- a/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess.go
+++ b/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess.go
@@ -145,8 +145,6 @@ type Process interface {
 // lifecycle of a Process.
 type TeardownFunc func() error
 
-var nilTeardownFunc = func() error { return nil }
-
 // ProcessFunc is a function that takes a process. Its main use case is goprocess.Go,
 // which spawns a ProcessFunc in its own goroutine, and returns a corresponding
 // Process object.
diff --git a/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess_test.go b/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess_test.go
index 81c195843..3a16de7e6 100644
--- a/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess_test.go
+++ b/Godeps/_workspace/src/github.com/jbenet/goprocess/goprocess_test.go
@@ -300,13 +300,11 @@ func TestAddChild(t *testing.T) {
 	testNone(t, Q)
 
 	go b.Close()
-	testNone(t, Q)
 	d.Close()
 	testStrs(t, Q, "b", "d")
 	testStrs(t, Q, "b", "d")
 
 	go a.Close()
-	testNone(t, Q)
 	c.Close()
 	testStrs(t, Q, "a", "c")
 	testStrs(t, Q, "a", "c")
diff --git a/Godeps/_workspace/src/github.com/jbenet/goprocess/impl-mutex.go b/Godeps/_workspace/src/github.com/jbenet/goprocess/impl-mutex.go
index c6acc4f41..a67deea75 100644
--- a/Godeps/_workspace/src/github.com/jbenet/goprocess/impl-mutex.go
+++ b/Godeps/_workspace/src/github.com/jbenet/goprocess/impl-mutex.go
@@ -25,10 +25,6 @@ type process struct {
 //  **after** entering <-Closing(), and
 //  **before** <-Closed().
 func newProcess(tf TeardownFunc) *process {
-	if tf == nil {
-		tf = nilTeardownFunc
-	}
-
 	return &process{
 		teardown: tf,
 		closed:   make(chan struct{}),
@@ -123,17 +119,19 @@ func (p *process) Go(f ProcessFunc) Process {
 // SetTeardown to assign a teardown function
 func (p *process) SetTeardown(tf TeardownFunc) {
 	if tf == nil {
-		tf = nilTeardownFunc
+		panic("cannot set nil TeardownFunc")
 	}
 
 	p.Lock()
-	if p.teardown == nil {
-		select {
-		case <-p.Closed():
-			p.teardown = tf
-			p.closeErr = tf()
-		default:
-		}
+	if p.teardown != nil {
+		panic("cannot SetTeardown twice")
+	}
+
+	p.teardown = tf
+	select {
+	case <-p.Closed():
+		p.closeErr = tf()
+	default:
 	}
 	p.Unlock()
 }
@@ -196,8 +194,10 @@ func (p *process) doClose() {
 		}
 	}
 
-	p.closeErr = p.teardown() // actually run the close logic (ok safe to teardown)
-	close(p.closed)           // signal that we're shut down (Closed)
+	if p.teardown != nil {
+		p.closeErr = p.teardown() // actually run the close logic (ok safe to teardown)
+	}
+	close(p.closed) // signal that we're shut down (Closed)
 
 	// go remove all the parents from the process links. optimization.
 	go func(waiters []*processLink) {