From 68d14e2cabf2a01c4d6d2ac19ac661205eeb875e Mon Sep 17 00:00:00 2001
From: Matteo Collina <hello@matteocollina.com>
Date: Fri, 21 Jul 2017 10:25:24 +0200
Subject: [PATCH] Do not forward $SYS topics for +/# subscriptions.

Fixes: https://github.com/mcollina/aedes/issues/135
---
 aedes.js                  |  6 +++++-
 lib/handlers/subscribe.js |  9 ++++++++-
 test/events.js            | 19 +++++++++++++++++++
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/aedes.js b/aedes.js
index 4e6bf1a1..133e351f 100644
--- a/aedes.js
+++ b/aedes.js
@@ -200,8 +200,12 @@ function DoEnqueues () {
   }
 }
 
+// + is 43
+// # is 35
 function removeSharp (sub) {
-  return sub.topic !== '#'
+  var code = sub.topic.charCodeAt(0)
+  console.log(sub.topic, code)
+  return code !== 43 && code !== 35
 }
 
 function doEnqueue (sub, done) {
diff --git a/lib/handlers/subscribe.js b/lib/handlers/subscribe.js
index ece4cb0f..e0848805 100644
--- a/lib/handlers/subscribe.js
+++ b/lib/handlers/subscribe.js
@@ -100,7 +100,7 @@ function subTopic (sub, done) {
       break
   }
 
-  if (sub.topic === '#') {
+  if (isWildcardThatMatchesSys(sub.topic)) {
     func = blockSys(func)
   }
 
@@ -118,6 +118,13 @@ function subTopic (sub, done) {
   }
 }
 
+// + is 43
+// # is 35
+function isWildcardThatMatchesSys (topic) {
+  var code = topic.charCodeAt(0)
+  return code === 43 || code === 35
+}
+
 function completeSubscribe (err) {
   var packet = this.packet
   var client = this.client
diff --git a/test/events.js b/test/events.js
index 0c4286d8..25df8ea3 100644
--- a/test/events.js
+++ b/test/events.js
@@ -40,6 +40,25 @@ test('does not forward $SYS topics to # subscription', function (t) {
   })
 })
 
+test('does not forward $SYS topics to +/# subscription', function (t) {
+  t.plan(4)
+  var s = connect(setup())
+
+  subscribe(t, s, '+/#', 0, function () {
+    s.outStream.once('data', function (packet) {
+      t.fail('no packet should be received')
+    })
+
+    s.broker.mq.emit({
+      cmd: 'publish',
+      topic: '$SYS/hello',
+      payload: 'world'
+    }, function () {
+      t.pass('nothing happened')
+    })
+  })
+})
+
 test('does not store $SYS topics to QoS 1 # subscription', function (t) {
   t.plan(3)