From 31cf6d965d3f1f6791779c4584dbbe78fd65eeff Mon Sep 17 00:00:00 2001
From: Johannes Schriewer <hallo@dunkelstern.de>
Date: Mon, 30 Jul 2018 02:54:37 +0200
Subject: [PATCH] Bugfix: Some packets need fixed flags in header, missed that
 in the spec

---
 src/packet.c          | 11 +++++++++++
 tests/decode_packet.c | 14 +++++++-------
 tests/encode_packet.c | 14 +++++++-------
 3 files changed, 25 insertions(+), 14 deletions(-)

diff --git a/src/packet.c b/src/packet.c
index e27f660..6714db2 100644
--- a/src/packet.c
+++ b/src/packet.c
@@ -376,6 +376,17 @@ Buffer *make_buffer_for_header(size_t sz, MQTTControlPacketType type) {
 
     Buffer *buffer = buffer_allocate(sz);
     buffer->data[0] = type << 4;
+
+    // MQTT Spec means we should set a bit in the flags field for some packet types
+    switch (type) {
+        case PacketTypePubRel:
+        case PacketTypeSubscribe:
+        case PacketTypeUnsubscribe:
+            buffer->data[0] |= 0x02;
+            break;
+        default:
+            break;
+    }
     buffer->position += 1;
     variable_length_int_encode(sz - 2, buffer);
     
diff --git a/tests/decode_packet.c b/tests/decode_packet.c
index 142a06b..fe87e22 100644
--- a/tests/decode_packet.c
+++ b/tests/decode_packet.c
@@ -260,7 +260,7 @@ TestResult test_decode_publish_with_msg(void) {
 TestResult test_decode_puback(void) {
     char data[] = {
         0x40, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x00, 0x0a  // packet id
     };
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     MQTTPacket *packet = mqtt_packet_decode(buffer);
@@ -280,7 +280,7 @@ TestResult test_decode_puback(void) {
 TestResult test_decode_pubrec(void) {
     char data[] = {
         0x50, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x00, 0x0a  // packet id
     };
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     MQTTPacket *packet = mqtt_packet_decode(buffer);
@@ -299,8 +299,8 @@ TestResult test_decode_pubrec(void) {
 
 TestResult test_decode_pubrel(void) {
     char data[] = {
-        0x60, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x62, 0x02, // header
+        0x00, 0x0a  // packet id
     };
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     MQTTPacket *packet = mqtt_packet_decode(buffer);
@@ -320,7 +320,7 @@ TestResult test_decode_pubrel(void) {
 TestResult test_decode_pubcomp(void) {
     char data[] = {
         0x70, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x00, 0x0a  // packet id
     };
     Buffer *buffer = buffer_from_data_copy(data, sizeof(data));
     MQTTPacket *packet = mqtt_packet_decode(buffer);
@@ -339,7 +339,7 @@ TestResult test_decode_pubcomp(void) {
 
 TestResult test_decode_subscribe(void) {
     char data[] = {
-        0x80, 0x0f, // header
+        0x82, 0x0f, // header
         0x00, 0x0a,  // packet id
         0x00, 0x0a, 't', 'e', 's', 't', '/', 't', 'o', 'p', 'i', 'c',
         0x01 // qos
@@ -385,7 +385,7 @@ TestResult test_decode_suback(void) {
 
 TestResult test_decode_unsubscribe(void) {
     char data[] = {
-        0xa0, 0x0e, // header
+        0xa2, 0x0e, // header
         0x00, 0x0a, // packet id
         0x00, 0x0a, 't', 'e', 's', 't', '/', 't', 'o', 'p', 'i', 'c',
     };
diff --git a/tests/encode_packet.c b/tests/encode_packet.c
index fbae50d..aa16672 100644
--- a/tests/encode_packet.c
+++ b/tests/encode_packet.c
@@ -302,7 +302,7 @@ TestResult test_encode_publish_with_msg(void) {
 TestResult test_encode_puback(void) {
     char data[] = {
         0x40, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x00, 0x0a  // packet id
     };
     PubAckPayload *payload = calloc(1, sizeof(PubAckPayload));
 
@@ -320,7 +320,7 @@ TestResult test_encode_puback(void) {
 TestResult test_encode_pubrec(void) {
     char data[] = {
         0x50, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x00, 0x0a  // packet id
     };
     PubRecPayload *payload = calloc(1, sizeof(PubRecPayload));
 
@@ -337,8 +337,8 @@ TestResult test_encode_pubrec(void) {
 
 TestResult test_encode_pubrel(void) {
     char data[] = {
-        0x60, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x62, 0x02, // header
+        0x00, 0x0a  // packet id
     };
     PubRelPayload *payload = calloc(1, sizeof(PubRelPayload));
 
@@ -356,7 +356,7 @@ TestResult test_encode_pubrel(void) {
 TestResult test_encode_pubcomp(void) {
     char data[] = {
         0x70, 0x02, // header
-        0x00, 0x0a  // packet id 
+        0x00, 0x0a  // packet id
     };
     PubCompPayload *payload = calloc(1, sizeof(PubCompPayload));
 
@@ -373,7 +373,7 @@ TestResult test_encode_pubcomp(void) {
 
 TestResult test_encode_subscribe(void) {
     char data[] = {
-        0x80, 0x0f, // header
+        0x82, 0x0f, // header
         0x00, 0x0a,  // packet id
         0x00, 0x0a, 't', 'e', 's', 't', '/', 't', 'o', 'p', 'i', 'c',
         0x01 // qos
@@ -415,7 +415,7 @@ TestResult test_encode_suback(void) {
 
 TestResult test_encode_unsubscribe(void) {
     char data[] = {
-        0xa0, 0x0e, // header
+        0xa2, 0x0e, // header
         0x00, 0x0a, // packet id
         0x00, 0x0a, 't', 'e', 's', 't', '/', 't', 'o', 'p', 'i', 'c',
     };