From 9cffcff7e812d469182d37fff11a9dead2ff4be3 Mon Sep 17 00:00:00 2001
From: Celtic Minstrel <celtic.minstrel.ca@some.place>
Date: Sun, 27 Aug 2017 09:30:54 -0400
Subject: [PATCH] Make it optional for the map generator user_config to return
 the new settings

---
 src/scripting/mapgen_lua_kernel.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/scripting/mapgen_lua_kernel.cpp b/src/scripting/mapgen_lua_kernel.cpp
index e531edc5c8e4..645a5ca2c46e 100644
--- a/src/scripting/mapgen_lua_kernel.cpp
+++ b/src/scripting/mapgen_lua_kernel.cpp
@@ -155,7 +155,7 @@ void mapgen_lua_kernel::run_generator(const char * prog, const config & generato
 void mapgen_lua_kernel::user_config(const char * prog, config & generator)
 {
 	run_generator(prog, generator);
-	if(!luaW_toconfig(mState, -1, generator)) {
+	if(!lua_isnoneornil(mState, -1) && !luaW_toconfig(mState, -1, generator)) {
 		std::string msg = "expected a string, found a ";
 		msg += lua_typename(mState, lua_type(mState, -1));
 		lua_pop(mState, 1);