Fix an npc delete race condition with LSL sensors where an initial presence check could succeed but then the npc removed before the subequent npc check.

The resulting null would cause an exception.  We now check for null before looking at SenseAsAgent.
Hopefully fixes http://opensimulator.org/mantis/view.php?id=5872

1 files changed, 20 insertions, 9 deletions

diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs
index 3e0e452..850f50b 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Implementation/Plugins/SensorRepeat.cs
@@ -445,17 +445,28 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api.Plugins
             Vector3 toRegionPos;
             double dis;
 
-            Action<ScenePresence> senseEntity = new Action<ScenePresence>(delegate(ScenePresence presence)
+            Action<ScenePresence> senseEntity = new Action<ScenePresence>(presence =>
             {
-                if ((ts.type & NPC) == 0
-                    && presence.PresenceType == PresenceType.Npc
-                    && !npcModule.GetNPC(presence.UUID, presence.Scene).SenseAsAgent)
-                    return;
+                if ((ts.type & NPC) == 0 && presence.PresenceType == PresenceType.Npc)
+                {
+                    INPC npcData = npcModule.GetNPC(presence.UUID, presence.Scene);
+                    if (npcData == null || !npcData.SenseAsAgent)
+                        return;
+                }
 
-                if ((ts.type & AGENT) == 0
-                    && (presence.PresenceType == PresenceType.User
-                        || npcModule.GetNPC(presence.UUID, presence.Scene).SenseAsAgent))
-                    return;
+                if ((ts.type & AGENT) == 0)
+                {
+                    if (presence.PresenceType == PresenceType.User)
+                    {
+                        return;
+                    }
+                    else
+                    {
+                        INPC npcData = npcModule.GetNPC(presence.UUID, presence.Scene);
+                        if (npcData != null && npcData.SenseAsAgent)
+                            return;
+                    }
+                }
 
                 if (presence.IsDeleted || presence.IsChildAgent || presence.GodLevel > 0.0)
                     return;