From 16d7ce7f1fbb8eb43417294fc52faa6f59a94faa Mon Sep 17 00:00:00 2001
From: JoePfeiffer <joseph@pfeifferfamily.net>
Date: Mon, 27 Jul 2020 11:59:25 -0600
Subject: [PATCH] Fixes Issue #718 Reset rocket's relative position when its
 absolute position is reset. Make sure rocket has lifted off before setting
 launch rod as cleared.

---
 .../sf/openrocket/simulation/BasicEventSimulationEngine.java  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java b/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java
index da54cc483..f952404ae 100644
--- a/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java
+++ b/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java
@@ -162,6 +162,7 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 					// Avoid sinking into ground before liftoff
 					if (relativePosition.z < 0) {
 						currentStatus.setRocketPosition(origin);
+						relativePosition = Coordinate.ZERO;
 						currentStatus.setRocketVelocity(originVelocity);
 					}
 					// Detect lift-off
@@ -181,7 +182,8 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 				}
 				
 				// Check for launch guide clearance
-				if (!currentStatus.isLaunchRodCleared() &&
+				if (currentStatus.isLiftoff() &&
+					!currentStatus.isLaunchRodCleared() &&
 						relativePosition.length() > currentStatus.getSimulationConditions().getLaunchRodLength()) {
 					addEvent(new FlightEvent(FlightEvent.Type.LAUNCHROD, currentStatus.getSimulationTime(), null));
 				}