Undead mobs take light damage only in sunlight

mods/ENTITIES/mobs/api.lua

@@ -617,21 +617,26 @@ local do_env_damage = function(self)
 		return
 	end
 
-	-- bright light harms mob
-	if self.light_damage ~= 0
-	and (minetest.get_node_light(pos) or 0) > 12 then
 
+	local deal_light_damage = function(self, pos, damage)
 		if not (mod_weather and (mcl_weather.rain.raining or mcl_weather.state == "snow") and mcl_weather.is_outdoor(pos)) then
-
+			self.health = self.health - damage
-			self.health = self.health - self.light_damage
 
 			effect(pos, 5, "tnt_smoke.png")
 
 			if check_for_death(self, "light", {type = "light"}) then return end
-
 		end
 	end
 
+	-- bright light harms mob
+	if self.light_damage ~= 0 and (minetest.get_node_light(pos) or 0) > 12 then
+		deal_light_damage(self, pos, self.light_damage)
+	end
+	local _, dim = mcl_worlds.y_to_layer(pos.y)
+	if self.sunlight_damage ~= 0 and (minetest.get_node_light(pos) or 0) >= minetest.LIGHT_MAX and dim == "overworld" then
+		deal_light_damage(self, pos, self.sunlight_damage)
+	end
+
 	local y_level = self.collisionbox[2]
 
 	if self.child then
@@ -3017,6 +3022,7 @@ minetest.register_entity(name, {
 	run_velocity = def.run_velocity or 2,
 	damage = max(0, (def.damage or 0) * difficulty),
 	light_damage = def.light_damage or 0,
+	sunlight_damage = def.sunlight_damage or 0,
 	water_damage = def.water_damage or 0,
 	lava_damage = def.lava_damage or 0,
 	suffocation = def.suffocation or 2,

mods/ENTITIES/mobs/api.txt

@@ -209,7 +209,8 @@ functions needed for the mob to work properly which contains the following:
 
       'ignores_nametag' if true, mob cannot be named by nametag
       'rain_damage' damage per second if mob is standing in rain (default: 0)
-
+      'sunlight_damage' holds the damage per second inflicted to mobs when they
+                        are in direct sunlight
 
 Node Replacement
 ----------------

mods/ENTITIES/mobs_mc/skeleton+stray.lua

@@ -79,7 +79,7 @@ local skeleton = {
 	},
 	water_damage = 1,
 	lava_damage = 4,
-	light_damage = 1,
+	sunlight_damage = 1,
 	view_range = 16,
 	fear_height = 4,
 	attack_type = "dogshoot",

mods/ENTITIES/mobs_mc/villager_zombie.lua

@@ -75,7 +75,7 @@ mobs:register_mob("mobs_mc:villager_zombie", {
 	},
 	water_damage = 1,
 	lava_damage = 5,
-	light_damage = 1,
+	sunlight_damage = 1,
 	view_range = 16,
 	fear_height = 5,
 

mods/ENTITIES/mobs_mc/zombie.lua

@@ -81,7 +81,7 @@ local zombie = {
 	},
 	lava_damage = 4,
 	-- TODO: Burn mob only when in direct sunlight
-	light_damage = 2,
+	sunlight_damage = 2,
 	view_range = 16,
 	attack_type = "dogfight",
 }
@@ -96,7 +96,7 @@ baby_zombie.collisionbox = {-0.25, -0.01, -0.25, 0.25, 0.94, 0.25}
 baby_zombie.visual_size = {x=zombie.visual_size.x/2, y=zombie.visual_size.y/2}
 baby_zombie.walk_velocity = 1.2
 baby_zombie.run_velocity = 2.4
-baby_zombie.light_damage = 0
+baby_zombie.sunlight_damage = 0
 
 mobs:register_mob("mobs_mc:baby_zombie", baby_zombie)
 
@@ -104,7 +104,7 @@ mobs:register_mob("mobs_mc:baby_zombie", baby_zombie)
 -- Desert variant of the zombie
 local husk = table.copy(zombie)
 husk.textures = {{"mobs_mc_husk.png"}}
-husk.light_damage = 0
+husk.sunlight_damage = 0
 husk.water_damage = 3
 husk.drops = drops_common
 -- TODO: Husks avoid water