nil check in do_states

api.lua

@@ -6,7 +6,7 @@ local use_cmi = minetest.global_exists("cmi")
 
 mobs = {
 	mod = "redo",
-	version = "20200701",
+	version = "20200720",
 	intllib = S,
 	invis = minetest.global_exists("invisibility") and invisibility or {}
 }
@@ -195,7 +195,7 @@ end
 
 -- calculate distance
 local get_distance = function(a, b)
-
+if not a or not b then return 50 end -- nil check
 	local x, y, z = a.x - b.x, a.y - b.y, a.z - b.z
 
 	return square(x * x + y * y + z * z)
@@ -1013,7 +1013,7 @@ function mob_class:do_env_damage()
 		self:update_tag()
 	end
 
-	local pos = self.object:get_pos()
+	local pos = self.object:get_pos() ; if not pos then return end
 
 	self.time_of_day = minetest.get_timeofday()
 
@@ -1831,7 +1831,7 @@ function mob_class:general_attack()
 		return
 	end
 
-	local s = self.object:get_pos()
+	local s = self.object:get_pos() ; if not s then return end
 	local objs = minetest.get_objects_inside_radius(s, self.view_range)
 
 	-- remove entities we aren't interested in
@@ -2001,7 +2001,7 @@ function mob_class:follow_flop()
 	and self.state ~= "attack"
 	and self.state ~= "runaway" then
 
-		local s = self.object:get_pos()
+		local s = self.object:get_pos() ; if not s then return end
 		local players = minetest.get_connected_players()
 
 		for n = 1, #players do
@@ -2132,11 +2132,11 @@ end
 -- execute current state (stand, walk, run, attacks)
 function mob_class:do_states(dtime)
 
-	local yaw = self.object:get_yaw() or 0
+	local yaw = self.object:get_yaw() ; if not yaw then return end
 
 	if self.state == "stand" then
 
-		if random(4) == 1 then
+		if self.randomly_turn and random(4) == 1 then
 
 			local lp
 			local s = self.object:get_pos()
@@ -2224,7 +2224,7 @@ function mob_class:do_states(dtime)
 			yaw = self:set_yaw(yaw, 8)
 
 		-- otherwise randomly turn
-		elseif random(100) <= 30 then
+		elseif self.randomly_turn and random(100) <= 30 then
 
 			yaw = yaw + random(-0.5, 0.5)
 
@@ -3564,6 +3564,7 @@ minetest.register_entity(name, setmetatable({
 	owner_loyal = def.owner_loyal,
 	pushable = def.pushable,
 	stay_near = def.stay_near,
+	randomly_turn = def.randomly_turn ~= false,
 
 	on_spawn = def.on_spawn,
 

api.txt

@@ -31,13 +31,15 @@ functions needed for the mob to work properly which contains the following:
    'hp_max'        has the maximum health value the mob can spawn with.
    'armor'         holds strength of mob, 100 is normal, lower is more powerful
                    and needs more hits and better weapons to kill.
-   'passive'       when true allows animals to defend themselves when hit,
+   'passive'       when false allows animals to defend themselves when hit,
                    otherwise they amble onwards.
    'walk_velocity' is the speed that your mob can walk around.
    'run_velocity'  is the speed your mob can run with, usually when attacking.
    'stand_chance'  has a 0-100 chance value your mob will stand from walking.
    'walk_chance'   has a 0-100 chance value your mob will walk from standing,
                    set to 0 for jumping mobs only.
+   'randomly_turn' if set to false then mob will not turn to face player or
+                   randomly turn while walking or standing.
    'jump'          when true allows your mob to jump updwards.
    'jump_height'   holds the height your mob can jump, 0 to disable jumping.
    'stepheight'    height of a block that your mob can easily walk up onto,