issue77: Fixed the invalid range error issue with the small matchee r…

…aw topic when compared with base raw topic length (#78)

* issue77: Fixed the invalid range error issue with the small matchee raw topic when compared with base raw topic length

* Add test case for range error fix & fix typo in comments

* Fix unit test failing in wildcard case

lib/src/mqtt_subscription_topic.dart

@@ -95,8 +95,16 @@ class MqttSubscriptionTopic extends MqttTopic {
           return false;
         }
       }
+      // If we're at the last fragment of the matchee rawTopic but there are
+      // more fragments in the lhs rawTopic then the matchee rawTopic
+      // is too specific to be a match.
+      if (i + 1 == matcheeTopic.topicFragments.length &&
+          topicFragments.length > matcheeTopic.topicFragments.length &&
+          lhsFragment != matcheeTopic.topicFragments[i]) {
+        return false;
+      }
       // If we're at the last fragment of the lhs rawTopic but there are
-      // more fragments in the in the matchee then the matchee rawTopic
+      // more fragments in the matchee then the matchee rawTopic
       // is too specific to be a match.
       if (i + 1 == topicFragments.length &&
           matcheeTopic.topicFragments.length > topicFragments.length) {

test/mqtt_client_base_test.dart

@@ -382,6 +382,15 @@ void main() {
       expect(
           subTopic.matches(MqttPublicationTopic('some/random/topic')), isFalse);
     });
+    test('different length topics do not match and do not throw range error',
+        () {
+      const topic = 'finance/ibm/closingprice/+/topic/sub';
+      final subTopic = MqttSubscriptionTopic(topic);
+      expect(
+          subTopic
+              .matches(MqttPublicationTopic('finance/ibm/closingprice/sub')),
+          isFalse);
+    });
     test(
         'MultiWildcard does not match topic with difference before Wildcard level',
         () {