From cdd4223813d3a871553a45b27e227fff722c09ac Mon Sep 17 00:00:00 2001
From: Sebastian Zagrodzki <sebek@zagrodzki.net>
Date: Wed, 26 Apr 2017 21:50:10 +0200
Subject: [PATCH] Handle a case where transfers channel was not closed
 properly.

---
 usb/transfer_stream.go      |  3 +++
 usb/transfer_stream_test.go | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/usb/transfer_stream.go b/usb/transfer_stream.go
index 8c79c5e..0190dc7 100644
--- a/usb/transfer_stream.go
+++ b/usb/transfer_stream.go
@@ -75,6 +75,9 @@ func (r ReadStream) Read(p []byte) (int, error) {
 		if err != nil {
 			// wait error aborts immediately, all remaining data is invalid.
 			t.free()
+			if s.delayedErr == nil {
+				close(s.transfers)
+			}
 			for t := range s.transfers {
 				t.cancel()
 				t.wait()
diff --git a/usb/transfer_stream_test.go b/usb/transfer_stream_test.go
index 352973e..31b2a1c 100644
--- a/usb/transfer_stream_test.go
+++ b/usb/transfer_stream_test.go
@@ -198,6 +198,18 @@ func TestReadStream(t *testing.T) {
 				{err: io.ErrClosedPipe},
 			},
 		},
+		{
+			desc: "fail quickly",
+			transfers: [][]fakeStreamResult{
+				{{waitErr: sentinelError}},
+				{{n: 500}},
+				{{n: 500}},
+			},
+			want: []readRes{
+				{err: sentinelError},
+				{err: io.ErrClosedPipe},
+			},
+		},
 	} {
 		t.Run(strconv.Itoa(tcNum), func(t *testing.T) {
 			t.Logf("Case %d: %s", tcNum, tc.desc)