From 68dec9af2dae7a46d2ad6a6be18150035ef1299c Mon Sep 17 00:00:00 2001
From: ThorstenB <brehmt@gmail.com>
Date: Sun, 26 Jun 2011 16:18:36 +0200
Subject: [PATCH] #178 related: avoid sim from freezing when FDM goes wild

---
 src/Instrumentation/heading_indicator_dg.cxx | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Instrumentation/heading_indicator_dg.cxx b/src/Instrumentation/heading_indicator_dg.cxx
index bb9c1620e..a4c478be0 100644
--- a/src/Instrumentation/heading_indicator_dg.cxx
+++ b/src/Instrumentation/heading_indicator_dg.cxx
@@ -153,6 +153,10 @@ HeadingIndicatorDG::update (double dt)
     _last_heading_deg = heading;
 
     heading += offset + align + error;
+    // sanity check: bail out when the FDM runs wild, to avoid
+    // SG_NORMALIZE_RANGE from freezing on huge/infinite numbers.
+    if (fabs(heading)>1e10)
+        return;
     SG_NORMALIZE_RANGE(heading, 0.0, 360.0);
 
     _heading_out_node->setDoubleValue(heading);
-- 
2.39.5