From 2f2b4a42a95c7a96e5e16b74ba1167690fcd6231 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 17 Aug 2005 16:05:04 -0300
Subject: [PATCH] luaL_checkudata raises an error if value is not correct (like
 other luaL_check functions)

---
 lauxlib.c | 25 +++++++++++++------------
 liolib.c  | 20 +++++++++-----------
 loadlib.c |  8 +++-----
 3 files changed, 25 insertions(+), 28 deletions(-)

diff --git a/lauxlib.c b/lauxlib.c
index 93cbff51..a828e612 100644
--- a/lauxlib.c
+++ b/lauxlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lauxlib.c,v 1.143 2005/08/10 18:47:09 roberto Exp roberto $
+** $Id: lauxlib.c,v 1.144 2005/08/15 14:12:32 roberto Exp roberto $
 ** Auxiliary functions for building Lua libraries
 ** See Copyright Notice in lua.h
 */
@@ -130,18 +130,19 @@ LUALIB_API void  luaL_getmetatable (lua_State *L, const char *tname) {
 
 
 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
-  const char *tn;
-  if (!lua_getmetatable(L, ud)) return NULL;  /* no metatable? */
-  lua_rawget(L, LUA_REGISTRYINDEX);  /* get registry[metatable] */
-  tn = lua_tostring(L, -1);
-  if (tn && (strcmp(tn, tname) == 0)) {
-    lua_pop(L, 1);
-    return lua_touserdata(L, ud);
-  }
-  else {
-    lua_pop(L, 1);
-    return NULL;
+  void *p = NULL;
+  if (lua_getmetatable(L, ud)) {
+    const char *tn;
+    lua_rawget(L, LUA_REGISTRYINDEX);  /* get registry[metatable] */
+    tn = lua_tostring(L, -1);
+    if (tn && (strcmp(tn, tname) == 0)) {
+      lua_pop(L, 1);
+      p = lua_touserdata(L, ud);
+    }
   }
+  if (p == NULL)
+    luaL_typerror(L, ud, tname);
+  return p;
 }
 
 
diff --git a/liolib.c b/liolib.c
index a029190d..ceee5371 100644
--- a/liolib.c
+++ b/liolib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: liolib.c,v 2.64 2005/07/12 14:32:08 roberto Exp roberto $
+** $Id: liolib.c,v 2.65 2005/08/15 14:12:32 roberto Exp roberto $
 ** Standard I/O (and system) library
 ** See Copyright Notice in lua.h
 */
@@ -50,17 +50,17 @@ static void fileerror (lua_State *L, int arg, const char *filename) {
 }
 
 
-static FILE **topfile (lua_State *L) {
-  FILE **f = (FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE);
-  if (f == NULL) luaL_argerror(L, 1, "bad file");
-  return f;
-}
+#define topfile(L)	((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
 
 
 static int io_type (lua_State *L) {
-  FILE **f = (FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE);
-  if (f == NULL) lua_pushnil(L);
-  else if (*f == NULL)
+  void *ud;
+  luaL_checkany(L, 1);
+  ud = lua_touserdata(L, 1);
+  lua_getfield(L, LUA_REGISTRYINDEX, LUA_FILEHANDLE);
+  if (ud == NULL || !lua_getmetatable(L, 1) || !lua_rawequal(L, -2, -1))
+    lua_pushnil(L);  /* not a file */
+  else if (*((FILE **)ud) == NULL)
     lua_pushliteral(L, "closed file");
   else
     lua_pushliteral(L, "file");
@@ -173,7 +173,6 @@ static int io_tmpfile (lua_State *L) {
 static FILE *getiofile (lua_State *L, int findex) {
   FILE *f;
   lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
-  lua_assert(luaL_checkudata(L, -1, LUA_FILEHANDLE));
   f = *(FILE **)lua_touserdata(L, -1);
   if (f == NULL)
     luaL_error(L, "standard %s file is closed", fnames[findex - 1]);
@@ -194,7 +193,6 @@ static int g_iofile (lua_State *L, int f, const char *mode) {
       tofile(L);  /* check that it's a valid file handle */
       lua_pushvalue(L, 1);
     }
-    lua_assert(luaL_checkudata(L, -1, LUA_FILEHANDLE));
     lua_rawseti(L, LUA_ENVIRONINDEX, f);
   }
   /* return current value */
diff --git a/loadlib.c b/loadlib.c
index d50a587a..81d46172 100644
--- a/loadlib.c
+++ b/loadlib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: loadlib.c,v 1.37 2005/08/10 18:06:58 roberto Exp roberto $
+** $Id: loadlib.c,v 1.38 2005/08/15 14:12:32 roberto Exp roberto $
 ** Dynamic library loader for Lua
 ** See Copyright Notice in lua.h
 **
@@ -289,10 +289,8 @@ static void **ll_register (lua_State *L, const char *path) {
 */
 static int gctm (lua_State *L) {
   void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
-  if (lib) {
-    if (*lib) ll_unloadlib(*lib);
-    *lib = NULL;  /* mark library as closed */
-  }
+  if (*lib) ll_unloadlib(*lib);
+  *lib = NULL;  /* mark library as closed */
   return 0;
 }