Use a Buffer instead of SharedBuffer in ConnectionCommand

This fixes #6373

src/network/connection.h

@@ -325,7 +325,7 @@ struct ConnectionCommand
 	Address address;
 	u16 peer_id = PEER_ID_INEXISTENT;
 	u8 channelnum = 0;
-	SharedBuffer<u8> data;
+	Buffer<u8> data;
 	bool reliable = false;
 	bool raw = false;
 

src/util/pointer.h

@@ -168,6 +168,18 @@ public:
 	/*
 		Copies whole buffer
 	*/
+	SharedBuffer(const Buffer<T> &buffer)
+	{
+		m_size = buffer.getSize();
+		if (m_size != 0) {
+				data = new T[m_size];
+				memcpy(data, *buffer, buffer.getSize());
+		}
+		else
+			data = NULL;
+		refcount = new unsigned int;
+		(*refcount) = 1;
+	}
 	~SharedBuffer()
 	{
 		drop();