From 850c847bbf5959f759248022323beb32f0470a6e Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Mon, 9 Nov 2015 11:57:25 -0800
Subject: [PATCH] Trap attempts to register more than one message handler at a
 time.

---
 firmware/common/message.hpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/firmware/common/message.hpp b/firmware/common/message.hpp
index 842561b3a..1bf74878f 100644
--- a/firmware/common/message.hpp
+++ b/firmware/common/message.hpp
@@ -29,6 +29,8 @@
 
 #include "utility.hpp"
 
+#include "ch.h"
+
 class Message {
 public:
 	static constexpr size_t MAX_SIZE = 276;
@@ -251,6 +253,9 @@ public:
 	using MessageHandler = std::function<void(Message* const p)>;
 
 	void register_handler(const Message::ID id, MessageHandler&& handler) {
+		if( map_[toUType(id)] != nullptr ) {
+			chDbgPanic("MsgDblReg");
+		}
 		map_[toUType(id)] = std::move(handler);
 	}