diff --git a/lbaselib.c b/lbaselib.c
index ccc3123a..ce868ef7 100644
--- a/lbaselib.c
+++ b/lbaselib.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.270 2011/11/23 17:29:04 roberto Exp roberto $
+** $Id: lbaselib.c,v 1.271 2011/11/29 15:55:08 roberto Exp roberto $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -297,14 +297,10 @@ static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
     *size = 0;
     return NULL;
   }
-  else if ((s = lua_tostring(L, -1)) != NULL) {
-    lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
-    return lua_tolstring(L, RESERVEDSLOT, size);
-  }
-  else {
+  else if ((s = lua_tostring(L, -1)) == NULL)
     luaL_error(L, "reader function must return a string");
-    return NULL;  /* to avoid warnings */
-  }
+  lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
+  return lua_tolstring(L, RESERVEDSLOT, size);
 }
 
 
diff --git a/lmem.c b/lmem.c
index 1ee7f23d..2f5cddd5 100644
--- a/lmem.c
+++ b/lmem.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.c,v 1.81 2010/12/20 19:40:07 roberto Exp roberto $
+** $Id: lmem.c,v 1.82 2011/09/20 19:25:23 roberto Exp roberto $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -63,9 +63,8 @@ void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems,
 }
 
 
-void *luaM_toobig (lua_State *L) {
+l_noret luaM_toobig (lua_State *L) {
   luaG_runerror(L, "memory allocation error: block too big");
-  return NULL;  /* to avoid warnings */
 }
 
 
diff --git a/lmem.h b/lmem.h
index 710a4904..276bb32a 100644
--- a/lmem.h
+++ b/lmem.h
@@ -1,5 +1,5 @@
 /*
-** $Id: lmem.h,v 1.35 2009/12/16 16:42:58 roberto Exp roberto $
+** $Id: lmem.h,v 1.36 2010/04/08 17:16:46 roberto Exp roberto $
 ** Interface to Memory Manager
 ** See Copyright Notice in lua.h
 */
@@ -17,7 +17,7 @@
 #define luaM_reallocv(L,b,on,n,e) \
 	((cast(size_t, (n)+1) <= MAX_SIZET/(e)) ?  /* +1 to avoid warnings */ \
 		luaM_realloc_(L, (b), (on)*(e), (n)*(e)) : \
-		luaM_toobig(L))
+		(luaM_toobig(L), NULL))
 
 #define luaM_freemem(L, b, s)	luaM_realloc_(L, (b), (s), 0)
 #define luaM_free(L, b)		luaM_realloc_(L, (b), sizeof(*(b)), 0)
@@ -37,7 +37,7 @@
 #define luaM_reallocvector(L, v,oldn,n,t) \
    ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t))))
 
-LUAI_FUNC void *luaM_toobig (lua_State *L);
+LUAI_FUNC l_noret luaM_toobig (lua_State *L);
 
 /* not to be called directly */
 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
diff --git a/ltable.c b/ltable.c
index 6ded0d93..86bfa792 100644
--- a/ltable.c
+++ b/ltable.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ltable.c,v 2.65 2011/09/30 12:45:27 roberto Exp roberto $
+** $Id: ltable.c,v 2.66 2011/11/28 17:25:48 roberto Exp roberto $
 ** Lua tables (hash)
 ** See Copyright Notice in lua.h
 */
@@ -141,7 +141,7 @@ static int findindex (lua_State *L, Table *t, StkId key) {
     return i-1;  /* yes; that's the index (corrected to C) */
   else {
     Node *n = mainposition(t, key);
-    do {  /* check whether `key' is somewhere in the chain */
+    for (;;) {  /* check whether `key' is somewhere in the chain */
       /* key may be dead already, but it is ok to use it in `next' */
       if (luaV_rawequalobj(gkey(n), key) ||
             (ttisdeadkey(gkey(n)) && iscollectable(key) &&
@@ -151,9 +151,9 @@ static int findindex (lua_State *L, Table *t, StkId key) {
         return i + t->sizearray;
       }
       else n = gnext(n);
-    } while (n);
-    luaG_runerror(L, "invalid key to " LUA_QL("next"));  /* key not found */
-    return 0;  /* to avoid warnings */
+      if (n == NULL)
+        luaG_runerror(L, "invalid key to " LUA_QL("next"));  /* key not found */
+    }
   }
 }