Fix some placer nil checks

mods/butterflies/init.lua

@@ -40,7 +40,7 @@ for i in ipairs (butter_list) do
 		},
 		floodable = true,
 		on_place = function(itemstack, placer, pointed_thing)
-			local player_name = placer:get_player_name()
+			local player_name = placer and placer:get_player_name() or ""
 			local pos = pointed_thing.above
 
 			if not minetest.is_protected(pos, player_name) and
@@ -73,7 +73,7 @@ for i in ipairs (butter_list) do
 		groups = {not_in_creative_inventory = 1},
 		floodable = true,
 		on_place = function(itemstack, placer, pointed_thing)
-			local player_name = placer:get_player_name()
+			local player_name = placer and placer:get_player_name() or ""
 			local pos = pointed_thing.above
 
 			if not minetest.is_protected(pos, player_name) and

mods/carts/cart_entity.lua

@@ -413,7 +413,8 @@ minetest.register_craftitem("carts:cart", {
 		minetest.sound_play({name = "default_place_node_metal", gain = 0.5},
 			{pos = pointed_thing.above}, true)
 
-		if not minetest.is_creative_enabled(placer:get_player_name()) then
+		local player_name = placer and placer:get_player_name() or ""
+		if not minetest.is_creative_enabled(player_name) then
 			itemstack:take_item()
 		end
 		return itemstack

mods/default/nodes.lua

@@ -1985,8 +1985,8 @@ minetest.register_node("default:sand_with_kelp", {
 
 	on_place = function(itemstack, placer, pointed_thing)
 		-- Call on_rightclick if the pointed node defines it
-		if pointed_thing.type == "node" and placer and
-				not placer:get_player_control().sneak then
+		if pointed_thing.type == "node" and not (placer and placer:is_player()
+				and placer:get_player_control().sneak) then
 			local node_ptu = minetest.get_node(pointed_thing.under)
 			local def_ptu = minetest.registered_nodes[node_ptu.name]
 			if def_ptu and def_ptu.on_rightclick then
@@ -2035,19 +2035,20 @@ minetest.register_node("default:sand_with_kelp", {
 --
 
 local function coral_on_place(itemstack, placer, pointed_thing)
-	if pointed_thing.type ~= "node" or not placer then
+	if pointed_thing.type ~= "node" then
 		return itemstack
 	end
 
-	local player_name = placer:get_player_name()
+	local player_name = placer and placer:get_player_name()
 	local pos_under = pointed_thing.under
 	local pos_above = pointed_thing.above
 	local node_under = minetest.get_node(pos_under)
 	local def_under = minetest.registered_nodes[node_under.name]
 
-	if def_under and def_under.on_rightclick and not placer:get_player_control().sneak then
+	if def_under and def_under.on_rightclick and not (
+		placer and placer:is_player() and placer:get_player_control().sneak) then
 		return def_under.on_rightclick(pos_under, node_under,
-				placer, itemstack, pointed_thing) or itemstack
+				placer, itemstack, pointed_thing)
 	end
 
 	if node_under.name ~= "default:coral_skeleton" or
@@ -2057,9 +2058,6 @@ local function coral_on_place(itemstack, placer, pointed_thing)
 
 	if minetest.is_protected(pos_under, player_name) or
 			minetest.is_protected(pos_above, player_name) then
-		default.log_player_action(placer,
-			"tried to place", itemstack:get_name(),
-			"at protected position", pos_under)
 		minetest.record_protection_violation(pos_under, player_name)
 		return itemstack
 	end

mods/default/trees.lua

@@ -488,16 +488,15 @@ function default.sapling_on_place(itemstack, placer, pointed_thing,
 			interval) then
 		minetest.record_protection_violation(pos, player_name)
 		-- Print extra information to explain
---		minetest.chat_send_player(player_name,
---			itemstack:get_definition().description .. " will intersect protection " ..
---			"on growth")
 		minetest.chat_send_player(player_name,
 		    S("@1 will intersect protection on growth.",
 			itemstack:get_definition().description))
 		return itemstack
 	end
 
+	if placer then
 		default.log_player_action(placer, "places node", sapling_name, "at", pos)
+	end
 
 	local take_item = not minetest.is_creative_enabled(player_name)
 	local newnode = {name = sapling_name}

mods/farming/api.lua

@@ -178,7 +178,9 @@ farming.place_seed = function(itemstack, placer, pointed_thing, plantname)
 	end
 
 	-- add the node and remove 1 item from the itemstack
+	if placer then
 		default.log_player_action(placer, "places node", plantname, "at", pt.above)
+	end
 	minetest.add_node(pt.above, {name = plantname, param2 = 1})
 	tick(pt.above)
 	if not minetest.is_creative_enabled(player_name) then

mods/tnt/init.lua

@@ -625,7 +625,7 @@ function tnt.register_tnt(def)
 			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
+				if placer and placer:is_player() then
 					local meta = minetest.get_meta(pos)
 					meta:set_string("owner", placer:get_player_name())
 				end