From e8286e8894cf132eeda4bac9924e5fd8c74a7eb2 Mon Sep 17 00:00:00 2001
From: DTA7 <dta7e@t-online.de>
Date: Thu, 21 Sep 2017 21:52:52 +0200
Subject: Set placer to nil instead of a non-functional one in item_OnPlace
 (#6449)

* Set placer to nil instead of a non-functional one

This requires nil checks in core.rotate_node and core.rotate_and_place.
---
 builtin/common/misc_helpers.lua | 14 ++++++++------
 src/script/cpp_api/s_item.cpp   |  7 ++++++-
 src/script/lua_api/l_env.cpp    |  5 ++---
 3 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/builtin/common/misc_helpers.lua b/builtin/common/misc_helpers.lua
index 1e282f886..51abed1be 100644
--- a/builtin/common/misc_helpers.lua
+++ b/builtin/common/misc_helpers.lua
@@ -349,7 +349,7 @@ if INIT == "game" then
 					itemstack, pointed_thing)
 			return
 		end
-		local fdir = core.dir_to_facedir(placer:get_look_dir())
+		local fdir = placer and core.dir_to_facedir(placer:get_look_dir()) or 0
 		local wield_name = itemstack:get_name()
 
 		local above = pointed_thing.above
@@ -369,9 +369,9 @@ if INIT == "game" then
 			iswall = false
 		end
 
-		if core.is_protected(pos, placer:get_player_name()) then
-			core.record_protection_violation(pos,
-					placer:get_player_name())
+		local name = placer and placer:get_player_name() or ""
+		if core.is_protected(pos, name) then
+			core.record_protection_violation(pos, name)
 			return
 		end
 
@@ -432,9 +432,11 @@ if INIT == "game" then
 	end
 
 	core.rotate_node = function(itemstack, placer, pointed_thing)
+		local name = placer and placer:get_player_name() or ""
+		local invert_wall = placer and placer:get_player_control().sneak or false
 		core.rotate_and_place(itemstack, placer, pointed_thing,
-				is_creative(placer:get_player_name()),
-				{invert_wall = placer:get_player_control().sneak})
+				is_creative(name),
+				{invert_wall = invert_wall})
 		return itemstack
 	end
 end
diff --git a/src/script/cpp_api/s_item.cpp b/src/script/cpp_api/s_item.cpp
index 032018f2f..e13da1c86 100644
--- a/src/script/cpp_api/s_item.cpp
+++ b/src/script/cpp_api/s_item.cpp
@@ -69,7 +69,12 @@ bool ScriptApiItem::item_OnPlace(ItemStack &item,
 
 	// Call function
 	LuaItemStack::create(L, item);
-	objectrefGetOrCreate(L, placer);
+
+	if (!placer)
+		lua_pushnil(L);
+	else
+		objectrefGetOrCreate(L, placer);
+
 	pushPointedThing(pointed);
 	PCALL_RES(lua_pcall(L, 3, 1, error_handler));
 	if (!lua_isnil(L, -1)) {
diff --git a/src/script/lua_api/l_env.cpp b/src/script/lua_api/l_env.cpp
index 393c4ed5f..46745facd 100644
--- a/src/script/lua_api/l_env.cpp
+++ b/src/script/lua_api/l_env.cpp
@@ -291,9 +291,8 @@ int ModApiEnvMod::l_place_node(lua_State *L)
 	pointed.type = POINTEDTHING_NODE;
 	pointed.node_abovesurface = pos;
 	pointed.node_undersurface = pos + v3s16(0,-1,0);
-	// Place it with a NULL placer (appears in Lua as a non-functional
-	// ObjectRef)
-	bool success = scriptIfaceItem->item_OnPlace(item, NULL, pointed);
+	// Place it with a NULL placer (appears in Lua as nil)
+	bool success = scriptIfaceItem->item_OnPlace(item, nullptr, pointed);
 	lua_pushboolean(L, success);
 	return 1;
 }
-- 
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