From b77d5979653b47b1c303fe2dbdb1297b6ce2bc10 Mon Sep 17 00:00:00 2001
From: James R <justsomejames2@gmail.com>
Date: Sun, 2 Feb 2020 15:08:22 -0800
Subject: [PATCH 1/3] userdataType can check light userdata too!

---
 src/lua_baselib.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/lua_baselib.c b/src/lua_baselib.c
index 66bd30e32..7c53fa99a 100644
--- a/src/lua_baselib.c
+++ b/src/lua_baselib.c
@@ -220,10 +220,16 @@ static const char *GetUserdataUType(lua_State *L)
 //   or players[0].powers -> "player_t.powers"
 static int lib_userdataType(lua_State *L)
 {
+	int type;
 	lua_settop(L, 1); // pop everything except arg 1 (in case somebody decided to add more)
-	luaL_checktype(L, 1, LUA_TUSERDATA);
-	lua_pushstring(L, GetUserdataUType(L));
-	return 1;
+	type = lua_type(L, 1);
+	if (type == LUA_TLIGHTUSERDATA || type == LUA_TUSERDATA)
+	{
+		lua_pushstring(L, GetUserdataUType(L));
+		return 1;
+	}
+	else
+		return luaL_typerror(L, 1, "userdata");
 }
 
 static int lib_isPlayerAdmin(lua_State *L)

From 0f3a44887c9349ca9c883cd8d8e138fcfb32724f Mon Sep 17 00:00:00 2001
From: James R <justsomejames2@gmail.com>
Date: Sun, 2 Feb 2020 15:19:19 -0800
Subject: [PATCH 2/3] LUA_PushLightUserdata takes the fun out of lib_cvFindVar

---
 src/lua_consolelib.c | 18 ++----------------
 src/lua_script.c     | 22 ++++++++++++++++++++++
 src/lua_script.h     |  1 +
 3 files changed, 25 insertions(+), 16 deletions(-)

diff --git a/src/lua_consolelib.c b/src/lua_consolelib.c
index 48f2e20a8..62d59e582 100644
--- a/src/lua_consolelib.c
+++ b/src/lua_consolelib.c
@@ -431,22 +431,8 @@ static int lib_cvRegisterVar(lua_State *L)
 
 static int lib_cvFindVar(lua_State *L)
 {
-	consvar_t *cv;
-	if (( cv = CV_FindVar(luaL_checkstring(L,1)) ))
-	{
-		lua_settop(L,1);/* We only want one argument in the stack. */
-		lua_pushlightuserdata(L, cv);/* Now the second value on stack. */
-		luaL_getmetatable(L, META_CVAR);
-		/*
-		The metatable is the last value on the stack, so this
-		applies it to the second value, which is the cvar.
-		*/
-		lua_setmetatable(L,2);
-		lua_pushvalue(L,2);
-		return 1;
-	}
-	else
-		return 0;
+	LUA_PushLightUserdata(L, CV_FindVar(luaL_checkstring(L,1)), META_CVAR);
+	return 1;
 }
 
 // CONS_Printf for a single player
diff --git a/src/lua_script.c b/src/lua_script.c
index 2538fb711..9d0a80f90 100644
--- a/src/lua_script.c
+++ b/src/lua_script.c
@@ -568,6 +568,28 @@ fixed_t LUA_EvalMath(const char *word)
 	return res;
 }
 
+/*
+LUA_PushUserdata but no userdata is created.
+You can't invalidate it therefore.
+*/
+
+void LUA_PushLightUserdata (lua_State *L, void *data, const char *meta)
+{
+	if (data)
+	{
+		lua_pushlightuserdata(L, data);
+		luaL_getmetatable(L, meta);
+		/*
+		The metatable is the last value on the stack, so this
+		applies it to the second value, which is the userdata.
+		*/
+		lua_setmetatable(L, -2);
+		lua_pushvalue(L, -1);
+	}
+	else
+		lua_pushnil(L);
+}
+
 // Takes a pointer, any pointer, and a metatable name
 // Creates a userdata for that pointer with the given metatable
 // Pushes it to the stack and stores it in the registry.
diff --git a/src/lua_script.h b/src/lua_script.h
index 8f27dcb4c..d54387175 100644
--- a/src/lua_script.h
+++ b/src/lua_script.h
@@ -46,6 +46,7 @@ void LUA_LoadLump(UINT16 wad, UINT16 lump);
 void LUA_DumpFile(const char *filename);
 #endif
 fixed_t LUA_EvalMath(const char *word);
+void LUA_PushLightUserdata(lua_State *L, void *data, const char *meta);
 void LUA_PushUserdata(lua_State *L, void *data, const char *meta);
 void LUA_InvalidateUserdata(void *data);
 void LUA_InvalidateLevel(void);

From 21794e7a949b9f746cb86c6986b95be52d57e7ec Mon Sep 17 00:00:00 2001
From: James R <justsomejames2@gmail.com>
Date: Sun, 2 Feb 2020 17:22:28 -0800
Subject: [PATCH 3/3] lua_pushvalue is unneeded

---
 src/lua_script.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/lua_script.c b/src/lua_script.c
index 9d0a80f90..02f78cd35 100644
--- a/src/lua_script.c
+++ b/src/lua_script.c
@@ -584,7 +584,6 @@ void LUA_PushLightUserdata (lua_State *L, void *data, const char *meta)
 		applies it to the second value, which is the userdata.
 		*/
 		lua_setmetatable(L, -2);
-		lua_pushvalue(L, -1);
 	}
 	else
 		lua_pushnil(L);