From 7c921d8c916dce2cc06a1f885198e8f1dca58622 Mon Sep 17 00:00:00 2001
From: lethosor <lethosor@gmail.com>
Date: Sat, 25 Jul 2020 13:02:35 -0400
Subject: [PATCH] Lua listdir_recursive: allow nil to be used for default
 arguments

https://github.com/DFHack/dfhack/pull/1609#issuecomment-663803777
---
 library/LuaApi.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/library/LuaApi.cpp b/library/LuaApi.cpp
index 5b731ecc7..25843875d 100644
--- a/library/LuaApi.cpp
+++ b/library/LuaApi.cpp
@@ -2404,10 +2404,10 @@ static int filesystem_listdir_recursive(lua_State *L)
     luaL_checktype(L,1,LUA_TSTRING);
     std::string dir=lua_tostring(L,1);
     int depth = 10;
-    if (lua_gettop(L) >= 2)
+    if (lua_gettop(L) >= 2 && !lua_isnil(L, 2))
         depth = luaL_checkint(L, 2);
     bool include_prefix = true;
-    if (lua_gettop(L) >= 3)
+    if (lua_gettop(L) >= 3 && !lua_isnil(L, 3))
         include_prefix = lua_toboolean(L, 3);
     std::map<std::string, bool> files;
     int err = DFHack::Filesystem::listdir_recursive(dir, files, depth, include_prefix);