Prevent divide by zero (#2106)

This forces all explosions to damage entities within the 1 node
range. If that needs to be disabled, the damage_radius needs to
be set to 0.

init.lua

@@ -86,8 +86,8 @@ end
 local basic_flame_on_construct -- cached value
 local function destroy(drops, npos, cid, c_air, c_fire,
 		on_blast_queue, on_construct_queue,
-		ignore_protection, ignore_on_blast)
-	if not ignore_protection and minetest.is_protected(npos, "") then
+		ignore_protection, ignore_on_blast, owner)
+	if not ignore_protection and minetest.is_protected(npos, owner) then
 		return cid
 	end
 
@@ -208,6 +208,7 @@ local function add_effects(pos, radius, drops)
 		collisiondetection = false,
 		vertical = false,
 		texture = "tnt_boom.png",
+		glow = 15,
 	})
 	minetest.add_particlespawner({
 		amount = 64,
@@ -266,13 +267,13 @@ function tnt.burn(pos, nodename)
 	elseif def.on_ignite then
 		def.on_ignite(pos)
 	elseif minetest.get_item_group(name, "tnt") > 0 then
+		minetest.swap_node(pos, {name = name .. "_burning"})
 		minetest.sound_play("tnt_ignite", {pos = pos})
-		minetest.set_node(pos, {name = name .. "_burning"})
 		minetest.get_node_timer(pos):start(1)
 	end
 end
 
-local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
+local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast, owner, explode_center)
 	pos = vector.round(pos)
 	-- scan for adjacent TNT nodes first, and enlarge the explosion
 	local vm1 = VoxelManip()
@@ -286,6 +287,10 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 	local c_tnt_burning = minetest.get_content_id("tnt:tnt_burning")
 	local c_tnt_boom = minetest.get_content_id("tnt:boom")
 	local c_air = minetest.get_content_id("air")
+	-- make sure we still have explosion even when centre node isnt tnt related
+	if explode_center then
+		count = 1
+	end
 
 	for z = pos.z - 2, pos.z + 2 do
 	for y = pos.y - 2, pos.y + 2 do
@@ -333,7 +338,7 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 			if cid ~= c_air then
 				data[vi] = destroy(drops, p, cid, c_air, c_fire,
 					on_blast_queue, on_construct_queue,
-					ignore_protection, ignore_on_blast)
+					ignore_protection, ignore_on_blast, owner)
 			end
 		end
 		vi = vi + 1
@@ -375,16 +380,26 @@ local function tnt_explode(pos, radius, ignore_protection, ignore_on_blast)
 		queued_data.fn(queued_data.pos)
 	end
 
+	minetest.log("action", "TNT owned by " .. owner .. " detonated at " ..
+		minetest.pos_to_string(pos) .. " with radius " .. radius)
+
 	return drops, radius
 end
 
 function tnt.boom(pos, def)
-	minetest.sound_play("tnt_explode", {pos = pos, gain = 1.5, max_hear_distance = 2*64})
+	def = def or {}
+	def.radius = def.radius or 1
+	def.damage_radius = def.damage_radius or def.radius * 2
+	local meta = minetest.get_meta(pos)
+	local owner = meta:get_string("owner")
+	if not def.explode_center then
 		minetest.set_node(pos, {name = "tnt:boom"})
+	end
+	minetest.sound_play("tnt_explode", {pos = pos, gain = 1.5, max_hear_distance = 2*64})
 	local drops, radius = tnt_explode(pos, def.radius, def.ignore_protection,
-			def.ignore_on_blast)
+			def.ignore_on_blast, owner, def.explode_center)
 	-- append entity drops
-	local damage_radius = (radius / def.radius) * def.damage_radius
+	local damage_radius = (radius / math.max(1, def.radius)) * def.damage_radius
 	entity_physics(pos, damage_radius, drops)
 	if not def.disable_drops then
 		eject_drops(drops, pos, radius)
@@ -400,12 +415,6 @@ minetest.register_node("tnt:boom", {
 	walkable = false,
 	drop = "",
 	groups = {dig_immediate = 3},
-	on_construct = function(pos)
-		minetest.get_node_timer(pos):start(0.4)
-	end,
-	on_timer = function(pos, elapsed)
-		minetest.remove_node(pos)
-	end,
 	-- unaffected by explosions
 	on_blast = function() end,
 })
@@ -508,8 +517,8 @@ minetest.register_node("tnt:gunpowder_burning", {
 	on_timer = function(pos, elapsed)
 		for dx = -1, 1 do
 		for dz = -1, 1 do
+			if math.abs(dx) + math.abs(dz) == 1 then
 				for dy = -1, 1 do
-			if not (dx == 0 and dz == 0) then
 					tnt.burn({
 						x = pos.x + dx,
 						y = pos.y + dy,
@@ -579,9 +588,16 @@ function tnt.register_tnt(def)
 			is_ground_content = false,
 			groups = {dig_immediate = 2, mesecon = 2, tnt = 1, flammable = 5},
 			sounds = default.node_sound_wood_defaults(),
+			after_place_node = function(pos, placer)
+				if placer:is_player() then
+					local meta = minetest.get_meta(pos)
+					meta:set_string("owner", placer:get_player_name())
+				end
+			end,
 			on_punch = function(pos, node, puncher)
 				if puncher:get_wielded_item():get_name() == "default:torch" then
-					minetest.set_node(pos, {name = name .. "_burning"})
+					minetest.swap_node(pos, {name = name .. "_burning"})
+					minetest.registered_nodes[name .. "_burning"].on_construct(pos)
 					minetest.log("action", puncher:get_player_name() ..
 						" ignites " .. node.name .. " at " ..
 						minetest.pos_to_string(pos))
@@ -600,10 +616,12 @@ function tnt.register_tnt(def)
 				}
 			},
 			on_burn = function(pos)
-				minetest.set_node(pos, {name = name .. "_burning"})
+				minetest.swap_node(pos, {name = name .. "_burning"})
+				minetest.registered_nodes[name .. "_burning"].on_construct(pos)
 			end,
 			on_ignite = function(pos, igniter)
-				minetest.set_node(pos, {name = name .. "_burning"})
+				minetest.swap_node(pos, {name = name .. "_burning"})
+				minetest.registered_nodes[name .. "_burning"].on_construct(pos)
 			end,
 		})
 	end