add protection and ownership checks to default metal sign

add ownership check to rotation of locked sign

init.lua

@@ -26,6 +26,9 @@ signs_lib.gettext = S
 -- text encoding
 dofile(signs_lib.path .. "/encoding.lua");
 
+-- Initialize character texture cache
+local ctexcache = {}
+
 
 local wall_dir_change = {
 	[0] = 4,
@@ -38,6 +41,11 @@ local wall_dir_change = {
 }
 
 signs_lib.wallmounted_rotate = function(pos, node, user, mode)
+	if minetest.is_protected(pos, user:get_player_name()) then
+		minetest.record_protection_violation(pos,
+		sender:get_player_name())
+		return false
+	end
 	if mode ~= screwdriver.ROTATE_FACE then return false end 
 	minetest.swap_node(pos, { name = node.name, param2 = wall_dir_change[node.param2 % 6] })
 	signs_lib.update_sign(pos,nil,nil,node)
@@ -45,6 +53,11 @@ signs_lib.wallmounted_rotate = function(pos, node, user, mode)
 end
 
 signs_lib.facedir_rotate = function(pos, node, user, mode)
+	if minetest.is_protected(pos, user:get_player_name()) then
+		minetest.record_protection_violation(pos,
+		sender:get_player_name())
+		return false
+	end
 	if mode ~= screwdriver.ROTATE_FACE then return false end
 	local newparam2 = (node.param2 %8) + 1
 	if newparam2 == 5 then
@@ -58,6 +71,11 @@ signs_lib.facedir_rotate = function(pos, node, user, mode)
 end
 
 signs_lib.facedir_rotate_simple = function(pos, node, user, mode)
+	if minetest.is_protected(pos, user:get_player_name()) then
+		minetest.record_protection_violation(pos,
+		sender:get_player_name())
+		return false
+	end
 	if mode ~= screwdriver.ROTATE_FACE then return false end
 	local newparam2 = (node.param2 %8) + 1
 	if newparam2 > 3 then newparam2 = 0 end
@@ -362,6 +380,9 @@ end
 -- make char texture file name
 -- if texture file does not exist use fallback texture instead
 local function char_tex(font_name, ch)
+	if ctexcache[font_name..ch] then
+		return ctexcache[font_name..ch], true
+	else
 		local c = ch:byte()
 		local exists, tex = file_exists(CHAR_PATH:format(font_name, c))
 		if exists and c ~= 14 then
@@ -369,7 +390,9 @@ local function char_tex(font_name, ch)
 		else
 			tex = CHAR_FILE:format(font_name, 0x0)
 		end
+		ctexcache[font_name..ch] = tex
 		return tex, exists
+	end
 end
 
 local function make_line_texture(line, lineno, pos)
@@ -884,13 +907,20 @@ minetest.register_node(":locked_sign:sign_wall_locked", {
 		return pname == owner or pname == minetest.settings:get("name")
 			or minetest.check_player_privs(pname, {sign_editor=true})
 	end,
-	on_rotate = signs_lib.wallmounted_rotate
+	on_rotate = function(pos, node, user, mode)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if owner == user:get_player_name() then
+			signs_lib.wallmounted_rotate(pos, node, user, mode)
+		else
+			return false
+		end
+	end
 })
 
 -- default metal sign, if defined
 
-if minetest.registered_nodes["default:sign_wall_steel"] then
-	minetest.register_node(":"..default_sign_metal, {
+minetest.register_node(":"..default_sign_metal, {
 	description = S("Sign"),
 	inventory_image = default_sign_metal_image,
 	wield_image = default_sign_metal_image,
@@ -913,14 +943,29 @@ if minetest.registered_nodes["default:sign_wall_steel"] then
 		signs_lib.destruct_sign(pos)
 	end,
 	on_receive_fields = function(pos, formname, fields, sender)
-			signs_lib.receive_fields(pos, formname, fields, sender)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		local pname = sender:get_player_name() or ""
+		if pname ~= owner and pname ~= minetest.settings:get("name")
+		  and not minetest.check_player_privs(pname, {sign_editor=true}) then
+			return
+		end
+		signs_lib.receive_fields(pos, formname, fields, sender, true)
 	end,
 	on_punch = function(pos, node, puncher)
 		signs_lib.update_sign(pos,nil,nil,node)
 	end,
-		on_rotate = signs_lib.wallmounted_rotate
-	})
-end
+	on_rotate = function(pos, node, user, mode)
+		local meta = minetest.get_meta(pos)
+		local owner = meta:get_string("owner")
+		if owner == user:get_player_name() then
+			signs_lib.wallmounted_rotate(pos, node, user, mode)
+		else
+			return false
+		end
+	end
+})
+
 
 -- metal, colored signs
 if enable_colored_metal_signs then