From 1342a82ba752c6e5498c88014c976295d53f41da Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Thu, 13 Dec 2012 09:03:42 +1100
Subject: [PATCH] HAL_AVR: catch atomic nesting errors

---
 libraries/AP_HAL_AVR/Scheduler.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libraries/AP_HAL_AVR/Scheduler.cpp b/libraries/AP_HAL_AVR/Scheduler.cpp
index d7221491b3..c415539d07 100644
--- a/libraries/AP_HAL_AVR/Scheduler.cpp
+++ b/libraries/AP_HAL_AVR/Scheduler.cpp
@@ -199,6 +199,10 @@ void AVRScheduler::begin_atomic() {
 }
 
 void AVRScheduler::end_atomic() {
+	if (_nested_atomic_ctr == 0) {
+        hal.uartA->println_P(PSTR("ATOMIC NESTING ERROR"));
+        return;
+    }
     _nested_atomic_ctr--;
     if (_nested_atomic_ctr == 0) {
         sei();