Fix //allocate with 0 nodes

worldedit/serialization.lua

@@ -196,7 +196,7 @@ end
 -- @return The number of nodes.
 function worldedit.allocate(origin_pos, value)
 	local nodes = load_schematic(value)
-	if not nodes then return nil end
+	if not nodes or #nodes == 0 then return nil end
 	return worldedit.allocate_with_nodes(origin_pos, nodes)
 end
 

worldedit_commands/init.lua

@@ -1163,9 +1163,15 @@ minetest.register_chatcommand("/allocate", {
 			return
 		elseif version > worldedit.LATEST_SERIALIZATION_VERSION then
 			worldedit.player_notify(name, "File was created with newer version of WorldEdit!")
+			return
 		end
 		local nodepos1, nodepos2, count = worldedit.allocate(pos, value)
 
+		if not nodepos1 then
+			worldedit.player_notify(name, "Schematic empty, nothing allocated")
+			return
+		end
+
 		worldedit.pos1[name] = nodepos1
 		worldedit.mark_pos1(name)
 		worldedit.pos2[name] = nodepos2