PIJSON::new* now accept optional initial fields

libs/main/io_devices/piethernet.h

@@ -325,10 +325,10 @@ public:
 	//! Network interface descriptor
 	struct PIP_EXPORT Interface {
 		//! System index
-		int index;
+		int index = -1;
 
 		//! MTU
-		int mtu;
+		int mtu   = 0;
 
 		//! System name
 		PIString name;
@@ -351,6 +351,9 @@ public:
 		//! Flags of interface
 		InterfaceFlags flags;
 
+		//! Returns if interface is active
+		bool isValid() const { return name.isNotEmpty(); }
+
 		//! Returns if interface is active
 		bool isActive() const { return flags[PIEthernet::ifActive]; }