properties starting with "server" can only be changed manually by players with the npc_master priv

README.md

@@ -350,6 +350,9 @@ and
 	custom_functions_you_can_override.lua
 You can also react to or limit normal property changes this way.
 
+Properties starting with "server" can only be changed by players who have
+the npc_master priv.
+
 Example for a property: mood of the NPC (raises when treated well, gets
 lowered when treated badly).
 

exec_apply_effects.lua

@@ -518,7 +518,7 @@ yl_speak_up.execute_effect = function(player, n_id, o_id, r)
 		local var_val = property_data.properties[r.r_value]
 		-- set the value of the variable
 		local new_value = yl_speak_up.execute_effect_get_new_value(r, var_val, nil)
-		local res = yl_speak_up.set_npc_property(pname, r.r_value, new_value)
+		local res = yl_speak_up.set_npc_property(pname, r.r_value, new_value, "effect")
 		if(res ~= "OK") then
 			yl_speak_up.debug_msg(player, n_id, o_id, tostring(r.r_id).." "..
 				"property: "..tostring(res))

fs_edit_general.lua

@@ -1653,6 +1653,8 @@ yl_speak_up.get_fs_edit_option_p_and_e_property = function(
 		"hypertext[1.2,7.0;16.0,2.5;some_text;<normal>"..
 			"<b>Note:</b> Properties are useful for NPC that have a generic "..
 			"behaviour and may vary their behaviour slightly.\n"..
+			"Properties starting with \"server\" can only be set or changed by "..
+			"players with the \"npc_master\" privilege."..
 			"</normal>]"
 end
 

fs_properties.lua

@@ -42,7 +42,7 @@ yl_speak_up.get_npc_properties = function(pname)
 end
 
 
-yl_speak_up.set_npc_property = function(pname, property_name, property_value)
+yl_speak_up.set_npc_property = function(pname, property_name, property_value, reason)
 	if(not(pname) or not(property_name) or property_name == "") then
 		return "No player name or property name given. Cannot load property data."
 	end
@@ -59,7 +59,16 @@ yl_speak_up.set_npc_property = function(pname, property_name, property_value)
 	end
 	-- properties of type self. are not set directly
 	if(string.sub(property_name, 1, 5) == "self.") then
-		return "This properties of the type \"self.\" cannot be modified."
+		return "Properties of the type \"self.\" cannot be modified."
+	end
+	-- properites starting with "server" can only be changed or added manually by
+	-- players with the npc_master priv
+	if(string.sub(property_name, 1, 6) == "server") then
+		if(not(reason) or reason ~= "manually" or not(pname)
+		  or not(minetest.check_player_privs(pname, {npc_master=true}))) then
+			return "Properties starting with \"server\" can only be changed by players "..
+				"who have the \"npc_master\" priv."
+		end
 	end
 	-- store it
 	property_data.entity.yl_speak_up.properties[property_name] = property_value
@@ -82,11 +91,11 @@ yl_speak_up.input_properties = function(player, formname, fields)
 
 	local selected_row = nil
 	if(fields and fields.store_new_val and fields.store_new_val ~= "" and fields.prop_val) then
-		yl_speak_up.set_npc_property(pname, fields.prop_name, fields.prop_val)
+		yl_speak_up.set_npc_property(pname, fields.prop_name, fields.prop_val, "manually")
 
 	elseif(fields and fields.delete_prop and fields.delete_prop ~= "") then
 		-- delete the old property
-		yl_speak_up.set_npc_property(pname, fields.prop_name, nil)
+		yl_speak_up.set_npc_property(pname, fields.prop_name, nil, "manually")
 
 	elseif(fields and fields.table_of_properties) then
 		local selected = minetest.explode_table_event(fields.table_of_properties)

fs_talkdialog.lua

@@ -39,7 +39,7 @@ yl_speak_up.input_talk = function(player, formname, fields)
 	end
 	if(new_move_order ~= "") then
 		local dialog = yl_speak_up.speak_to[pname].dialog
-		yl_speak_up.set_npc_property(pname, "self.order", new_move_order)
+		yl_speak_up.set_npc_property(pname, "self.order", new_move_order, "move_order")
 		minetest.chat_send_player(pname,
 			tostring(dialog.n_npc or "NPC").." tells you: "..
 				"Ok. I will "..tostring(new_move_order)..".")