From 3f6b228d075e3e2f2bdc71f73b5dece26678692c Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Wed, 27 Apr 2016 10:09:54 +0700
Subject: [PATCH] fix splitting of StreamFrames in PacketPacker

---
 packet_packer.go      |  6 +++---
 packet_packer_test.go | 23 +++++++++++++++++++++++
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/packet_packer.go b/packet_packer.go
index 1618f56c2..b132377fc 100644
--- a/packet_packer.go
+++ b/packet_packer.go
@@ -116,7 +116,7 @@ func (p *packetPacker) composeNextPacket(controlFrames []frames.Frame, includeSt
 	}
 
 	for len(p.queuedStreamFrames) > 0 {
-		frame := p.queuedStreamFrames[0]
+		frame := &p.queuedStreamFrames[0]
 
 		if payloadLength > protocol.MaxFrameSize {
 			panic("internal inconsistency: packet payload too large")
@@ -131,7 +131,7 @@ func (p *packetPacker) composeNextPacket(controlFrames []frames.Frame, includeSt
 		previousFrame := frame.MaybeSplitOffFrame(protocol.MaxFrameSize - payloadLength)
 		if previousFrame != nil {
 			// Don't pop the queue, leave the modified frame in
-			frame = *previousFrame
+			frame = previousFrame
 			payloadLength += len(previousFrame.Data) - 1
 		} else {
 			p.queuedStreamFrames = p.queuedStreamFrames[1:]
@@ -139,7 +139,7 @@ func (p *packetPacker) composeNextPacket(controlFrames []frames.Frame, includeSt
 		}
 
 		payloadLength += frame.MinLength()
-		payloadFrames = append(payloadFrames, &frame)
+		payloadFrames = append(payloadFrames, frame)
 	}
 
 	return payloadFrames, nil
diff --git a/packet_packer_test.go b/packet_packer_test.go
index 94a0a31e0..4b2989636 100644
--- a/packet_packer_test.go
+++ b/packet_packer_test.go
@@ -136,6 +136,26 @@ var _ = Describe("Packet packer", func() {
 			Expect(len(payloadFrames)).To(Equal(0))
 		})
 
+		It("splits one stream frame larger than maximum size", func() {
+			maxStreamFrameDataLen := protocol.MaxFrameSize - (1 + 4 + 8 + 2)
+			f := frames.StreamFrame{
+				Data:   bytes.Repeat([]byte{'f'}, maxStreamFrameDataLen+200),
+				Offset: 1,
+			}
+			packer.AddStreamFrame(f)
+			payloadFrames, err := packer.composeNextPacket([]frames.Frame{}, true)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(payloadFrames)).To(Equal(1))
+			Expect(len(payloadFrames[0].(*frames.StreamFrame).Data)).To(Equal(maxStreamFrameDataLen))
+			payloadFrames, err = packer.composeNextPacket([]frames.Frame{}, true)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(payloadFrames)).To(Equal(1))
+			Expect(len(payloadFrames[0].(*frames.StreamFrame).Data)).To(Equal(200))
+			payloadFrames, err = packer.composeNextPacket([]frames.Frame{}, true)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(len(payloadFrames)).To(Equal(0))
+		})
+
 		It("packs 2 stream frames that are too big for one packet correctly", func() {
 			maxStreamFrameDataLen := protocol.MaxFrameSize - (1 + 4 + 8 + 2)
 			f1 := frames.StreamFrame{
@@ -157,6 +177,9 @@ var _ = Describe("Packet packer", func() {
 			p, err = packer.PackPacket([]frames.Frame{}, true)
 			Expect(err).ToNot(HaveOccurred())
 			Expect(p).ToNot(BeNil())
+			p, err = packer.PackPacket([]frames.Frame{}, true)
+			Expect(err).ToNot(HaveOccurred())
+			Expect(p).To(BeNil())
 		})
 
 		It("packs a packet that has the maximum packet size when given a large enough stream frame", func() {