Fix issues pointed out in PR comments

Author: AniruddhaKanhere

.github/workflows/ci.yml

@@ -83,7 +83,7 @@ jobs:
         uses: FreeRTOS/CI-CD-Github-Actions/coverage-cop@main
         with:
           coverage-file: ./build/coverage.info
-          line-coverage-min: 94
+          branch-coverage-min: 94
 
   complexity:
     runs-on: ubuntu-latest

source/core_mqtt.c

@@ -2359,10 +2359,8 @@ static MQTTStatus_t receiveSingleIteration( MQTTContext_t * pContext,
         /* If the MQTT Packet size is bigger than the buffer itself. */
         else if( totalMQTTPacketLength > pContext->networkBuffer.size )
         {
-            LogError( ( "Incoming packet size is bigger than MQTT buffer size. "
-                        "coreMQTT cannot handle such packets as 'dropping' packets is "
-                        "not allowed by the MQTT spec. Application MUST provide a bigger "
-                        "buffer to handle such packets." ) );
+            LogError( ( "Incoming packet size is bigger than MQTT buffer size. Total packet length %" PRIu32, 
+                        totalMQTTPacketLength ) );
             status = MQTTRecvFailed;
         }
         /* If the total packet is of more length than the bytes we have available. */
@@ -4314,7 +4312,7 @@ MQTTStatus_t MQTT_Connect( MQTTContext_t * pContext,
         if( pBackupPropBuilder != NULL )
         {
             bool isRequestProblemInfoSet;
-            uint32_t packetMaxSize;
+            uint32_t packetMaxSize = UINT32_MAX;
             status = MQTT_ValidateConnectProperties( pBackupPropBuilder,
                                                      &isRequestProblemInfoSet,
                                                      &packetMaxSize );
@@ -4343,11 +4341,9 @@ MQTTStatus_t MQTT_Connect( MQTTContext_t * pContext,
 
             assert( !CHECK_SIZE_T_OVERFLOWS_32BIT( pContext->networkBuffer.size ) );
 
-            LogWarn( ( "Application has not set any properties. coreMQTT will add a property to "
-                       "set the maximum packet size received from the server. This prevents the case "
-                       "when the incoming packet is greater than the buffer size. In such case, the "
-                       "packet cannot be dropped by the library neither can it be processed. Setting "
-                       "the value of the property to: %" PRIu32, ( uint32_t ) pContext->networkBuffer.size ) );
+            LogInfo( ( "Application has not set any properties. Adding a property to set the maximum "
+                       "packet size received from the server for the client to be %" PRIu32 ".",
+                       ( uint32_t ) pContext->networkBuffer.size ) );
             status = MQTTPropAdd_MaxPacketSize( pBackupPropBuilder,
                                                 pContext->networkBuffer.size,
                                                 NULL );

source/include/core_mqtt.h

@@ -731,6 +731,13 @@ MQTTStatus_t MQTT_CheckConnectStatus( const MQTTContext_t * pContext );
  * #MQTTEventCallbackFailed if the user defined callback fails.<br>
  * #MQTTSuccess otherwise.<br>
  *
+ * @note If no properties are provided (by setting @p pPropertyBuilder to NULL), coreMQTT
+ * will add a property to the connect packet to limit the maximum packet size that the
+ * broker can send to be equal to the application provided buffer to the #MQTT_Init API.
+ * This prevents the case when the packet is bigger than the buffer at which point,
+ * coreMQTT cannot handle the packet, neither can it drop it as MQTT protocol doesn't
+ * allow it.
+ * 
  * @note This API may spend more time than provided in the timeoutMS parameters in
  * certain conditions as listed below:
  *

test/unit-test/core_mqtt_utest.c

@@ -9640,7 +9640,7 @@ void test_MQTT_MatchTopic_topicNameLength_Overflow( void )
     size_t topicFilterlen = 14;
     bool matchResult = false;
 
-    /* NULL topic name. */
+    /* Topic name length more than maximum allowed length. */
     TEST_ASSERT_EQUAL( MQTTBadParameter, MQTT_MatchTopic( pTopicName,
                                                           topicNameLength,
                                                           pTopicFilter,
@@ -9656,7 +9656,7 @@ void test_MQTT_MatchTopic_topicFilterLength_Overflow( void )
     size_t topicFilterlen = 65536;
     bool matchResult = false;
 
-    /* NULL topic name. */
+    /* Topic filter length more than maximum allowed length. */
     TEST_ASSERT_EQUAL( MQTTBadParameter, MQTT_MatchTopic( pTopicName,
                                                           topicNameLength,
                                                           pTopicFilter,