support mapsync change dispatch

.luacheckrc

@@ -11,5 +11,8 @@ read_globals = {
 	"vector", "ItemStack",
 	"dump", "dump2",
 	"VoxelArea",
-	"minetest"
+	"minetest",
+
+	-- mods
+	"mapsync"
 }

mod.conf

@@ -1,3 +1,4 @@
 name = pick_and_place
 description = Pick and place utility
-depends = wield_events
+depends = wield_events
+optional_depends = mapsync

place_tool.lua

@@ -1,3 +1,5 @@
+local has_mapsync = minetest.get_modpath("mapsync")
+
 minetest.register_tool("pick_and_place:place", {
     description = "Placement tool",
     inventory_image = "pick_and_place_plus.png^[colorize:#0000ff",
@@ -47,6 +49,10 @@ minetest.register_tool("pick_and_place:place", {
             -- build preview
             pick_and_place.show_preview(playername, "pick_and_place_plus.png", "#0000ff", pos1, pos2)
         end
+
+        if has_mapsync then
+            mapsync.mark_changed(pos1, pos2)
+        end
     end,
     on_deselect = function(_, player)
         local playername = player:get_player_name()