From 07d712d5aecbf7b8628f83d803fafeda25eb929a Mon Sep 17 00:00:00 2001
From: Michael Zanetti <michael_zanetti@gmx.net>
Date: Tue, 24 Sep 2019 20:38:01 +0200
Subject: [PATCH] Fix a crash in topic matching.

Subscribing a client to a/b/c and publishing to a/b leads to a
crash, turns out it is a off-by-one calculation in topic matching code.
---
 libnymea-mqtt/mqttserver.cpp       | 3 +++
 tests/operation/test_operation.cpp | 1 +
 2 files changed, 4 insertions(+)

diff --git a/libnymea-mqtt/mqttserver.cpp b/libnymea-mqtt/mqttserver.cpp
index b0a37cb..b7e86e4 100644
--- a/libnymea-mqtt/mqttserver.cpp
+++ b/libnymea-mqtt/mqttserver.cpp
@@ -628,6 +628,9 @@ bool MqttServerPrivate::matchTopic(const QString &topicFilter, const QString &to
         if (filterParts.at(i) == QStringLiteral("#")) {
             continue;
         }
+        if (topicParts.length() <= i) {
+            return false;
+        }
         if (topicParts.at(i) == filterParts.at(i)) {
             continue;
         }
diff --git a/tests/operation/test_operation.cpp b/tests/operation/test_operation.cpp
index b5ee4a9..d5afe57 100644
--- a/tests/operation/test_operation.cpp
+++ b/tests/operation/test_operation.cpp
@@ -489,6 +489,7 @@ void OperationTests::testSubscriptionTopicMatching_data()
     rows.append({ "a//+/", "a///", "1" });
     rows.append({ "a//+/#", "a//b/c", "1" });
     rows.append({ "a//+/#", "a/b/c/d", "0" });
+    rows.append({ "a/b/c", "a/b", "0"});
 
     rows.append({ "$SYS/", "$SYS/", "0" });
     rows.append({ "#", "$SYS/", "0" });