Allow IP address to be passed into gethostbyname().

Ensure xNetworkBuffersInitialise() doesn't use a semaphore before it has been tested against NULL.

FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/FreeRTOS_DNS.c

@@ -404,9 +404,19 @@ TickType_t xReadTimeOut_ms = 1200U;
  as gethostbyname() may be called from different threads */
 TickType_t xIdentifier = ( TickType_t )usIdentifier++;
 
+	/* If the supplied hostname is IP address, convert it to uint32_t
+	and return. */
+	#if( ipconfigINCLUDE_FULL_INET_ADDR == 1 )
+	{
+		ulIPAddress = FreeRTOS_inet_addr( pcHostName );
+	}
+	#endif /* ipconfigINCLUDE_FULL_INET_ADDR == 1 */
+
 	/* If a DNS cache is used then check the cache before issuing another DNS
 	request. */
 	#if( ipconfigUSE_DNS_CACHE == 1 )
+	{
+		if( ulIPAddress == 0UL )
 		{
 			ulIPAddress = FreeRTOS_dnslookup( pcHostName );
 			if( ulIPAddress != 0 )
@@ -415,7 +425,8 @@ TickType_t xIdentifier = ( TickType_t )usIdentifier++;
 			}
 			else
 			{
-			/* prvGetHostByName will be called to start a DNS lookup. */
+				/* prvGetHostByName will be called to start a DNS lookup */
+			}
 		}
 	}
 	#endif /* ipconfigUSE_DNS_CACHE == 1 */

FreeRTOS-Plus/Source/FreeRTOS-Plus-TCP/portable/BufferManagement/BufferAllocation_2.c

@@ -103,6 +103,9 @@ BaseType_t xReturn, x;
 	{
 		xNetworkBufferSemaphore = xSemaphoreCreateCounting( ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS, ipconfigNUM_NETWORK_BUFFER_DESCRIPTORS );
 		configASSERT( xNetworkBufferSemaphore );
+
+		if( xNetworkBufferSemaphore != NULL )
+		{
 			#if ( configQUEUE_REGISTRY_SIZE > 0 )
 			{
 				vQueueAddToRegistry( xNetworkBufferSemaphore, "NetBufSem" );
@@ -119,8 +122,6 @@ BaseType_t xReturn, x;
 			}
 			#endif /*  ipconfigINCLUDE_EXAMPLE_FREERTOS_PLUS_TRACE_CALLS == 1 */
 
-		if( xNetworkBufferSemaphore != NULL )
-		{
 			vListInitialise( &xFreeBuffersList );
 
 			/* Initialise all the network buffers.  No storage is allocated to