From 436cb468e9a832d15009d527d80c8dfe86bb2772 Mon Sep 17 00:00:00 2001
From: ShadowNinja <shadowninja@minetest.net>
Date: Fri, 21 Nov 2014 11:32:01 -0500
Subject: [PATCH] Add minetest.global_exists()

---
 builtin/common/strict.lua | 5 +++++
 doc/lua_api.txt           | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/builtin/common/strict.lua b/builtin/common/strict.lua
index c353bb913..c7b86461f 100644
--- a/builtin/common/strict.lua
+++ b/builtin/common/strict.lua
@@ -4,6 +4,11 @@
 local WARN_INIT = false
 
 
+function core.global_exists(name)
+	return rawget(_G, name) ~= nil
+end
+
+
 local function warn(message)
 	print(os.date("%H:%M:%S: WARNING: ")..message)
 end
diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index d9ab6a459..6325ed35d 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -2289,6 +2289,9 @@ These functions return the leftover itemstack.
 
 Please note that forceloaded areas are saved when the server restarts.
 
+minetest.global_exists(name)
+^ Checks if a global variable has been set, without triggering a warning.
+
 ### Global objects
 * `minetest.env`: `EnvRef` of the server environment and world.
     * Any function in the minetest namespace can be called using the syntax
@@ -2479,7 +2482,7 @@ This is basically a reference to a C++ `ServerActiveObject`
             {x=189, y=198}, -- <  dig animation key frames
             {x=200, y=219}, -- <  walk+dig animation key frames
             frame_speed=30): -- <  animation frame speed
-            
+
 * `set_eye_offset({x=0,y=0,z=0},{x=0,y=0,z=0})`: defines offset value for camera per player
     * in first person view
     * in third person view (max. values `{x=-10/10,y=-10,15,z=-5/5}`)