diag: more diag when needed

We can delete this branch if the root cause turns out
to be once again the deadly FS25_OzdokenRCPack mod.

#761

Author: Peter Vaiko

scripts/Waypoint.lua

@@ -324,8 +324,8 @@ function WaypointNode:setToWaypoint(course, ix, suppressLog)
 	end
 	self.ix = newIx
 	local x, y, z = course:getWaypointPosition(self.ix)
-	if x ~= x then
-		CpUtil.infoVehicle(CpDebug.DBG_PPC, course.vehicle, 'PPC: %s waypoint %d position is NaN', getName(self.node), ix)
+	if x ~= x or y ~= y or z ~= z then
+		CpUtil.infoVehicle(course.vehicle, 'PPC: %s waypoint %d position is NaN', getName(self.node), ix)
 		course:print()
 		return
 	end

scripts/ai/PurePursuitController.lua

@@ -394,6 +394,14 @@ end
 function PurePursuitController:findRelevantSegment()
     -- vehicle position
     local vx, vy, vz = getWorldTranslation(self.controlledNode)
+    if MathUtil.isNan(vx) or MathUtil.isNan(vz) or MathUtil.isNan(vy) then
+        self:infoVehicle(self.vehicle, 'findRelevantSegment: vehicle position is NaN: (%s, %s, %s), controlled node %s',
+                tostring(vx), tostring(vy), tostring(vz), tostring(self.controlledNode))
+        self:infoVehicle(self.vehicle, self.controlledNode and getName(self.controlledNode) or 'controlled node lost')
+        self.course:print()
+        self:infoVehicle('findRelevantSegment: aiTrafficCollisionTranslation %s',
+                self.vehicle.spec_aiFieldWorker.aiTrafficCollisionTranslation and tostring(self.vehicle.spec_aiFieldWorker.aiTrafficCollisionTranslation[1]) or 'nil')
+    end
     -- update the position of the relevant node (in case the course offset changed)
     self.relevantWpNode:setToWaypoint(self.course, self.relevantWpNode.ix)
     local lx, _, dzFromRelevant = worldToLocal(self.relevantWpNode.node, vx, vy, vz);