1 files changed, 29 insertions, 20 deletions

diff --git a/src/lvm.c b/src/lvm.c
index e4f90af4..de340776 100644
--- a/src/lvm.c
+++ b/src/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 2.141 2011/06/09 18:24:22 roberto Exp $
+** $Id: lvm.c,v 2.144 2011/10/07 20:45:19 roberto Exp $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -127,29 +127,38 @@ void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
 
 void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
   int loop;
-  TValue temp;
   for (loop = 0; loop < MAXTAGLOOP; loop++) {
     const TValue *tm;
     if (ttistable(t)) {  /* `t' is a table? */
       Table *h = hvalue(t);
-      TValue *oldval = luaH_set(L, h, key); /* do a primitive set */
-      if (!ttisnil(oldval) ||  /* result is not nil? */
-          (tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL) { /* or no TM? */
-        setobj2t(L, oldval, val);
+      TValue *oldval = cast(TValue *, luaH_get(h, key));
+      /* if previous value is not nil, there must be a previous entry
+         in the table; moreover, a metamethod has no relevance */
+      if (!ttisnil(oldval) ||
+         /* previous value is nil; must check the metamethod */
+         ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL &&
+         /* no metamethod; is there a previous entry in the table? */
+         (oldval != luaO_nilobject ||
+         /* no previous entry; must create one. (The next test is
+            always true; we only need the assignment.) */
+         (oldval = luaH_newkey(L, h, key), 1)))) {
+        /* no metamethod and (now) there is an entry with given key */
+        setobj2t(L, oldval, val);  /* assign new value to that entry */
+        invalidateTMcache(h);
         luaC_barrierback(L, obj2gco(h), val);
         return;
       }
-      /* else will try the tag method */
+      /* else will try the metamethod */
     }
-    else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
-      luaG_typeerror(L, t, "index");
+    else  /* not a table; check metamethod */
+      if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
+        luaG_typeerror(L, t, "index");
+    /* there is a metamethod */
     if (ttisfunction(tm)) {
       callTM(L, tm, t, key, val, 0);
       return;
     }
-    /* else repeat with 'tm' */
-    setobj(L, &temp, tm);  /* avoid pointing inside table (may rehash) */
-    t = &temp;
+    t = tm;  /* else repeat with 'tm' */
   }
   luaG_runerror(L, "loop in settable");
 }
@@ -217,9 +226,9 @@ int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) {
     return luai_numlt(L, nvalue(l), nvalue(r));
   else if (ttisstring(l) && ttisstring(r))
     return l_strcmp(rawtsvalue(l), rawtsvalue(r)) < 0;
-  else if ((res = call_orderTM(L, l, r, TM_LT)) != -1)
-    return res;
-  return luaG_ordererror(L, l, r);
+  else if ((res = call_orderTM(L, l, r, TM_LT)) < 0)
+    luaG_ordererror(L, l, r);
+  return res;
 }
 
 
@@ -229,11 +238,11 @@ int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) {
     return luai_numle(L, nvalue(l), nvalue(r));
   else if (ttisstring(l) && ttisstring(r))
     return l_strcmp(rawtsvalue(l), rawtsvalue(r)) <= 0;
-  else if ((res = call_orderTM(L, l, r, TM_LE)) != -1)  /* first try `le' */
+  else if ((res = call_orderTM(L, l, r, TM_LE)) >= 0)  /* first try `le' */
     return res;
-  else if ((res = call_orderTM(L, r, l, TM_LT)) != -1)  /* else try `lt' */
-    return !res;
-  return luaG_ordererror(L, l, r);
+  else if ((res = call_orderTM(L, r, l, TM_LT)) < 0)  /* else try `lt' */
+    luaG_ordererror(L, l, r);
+  return !res;
 }
 
 
@@ -808,7 +817,7 @@ void luaV_execute (lua_State *L) {
           luaH_resizearray(L, h, last);  /* pre-allocate it at once */
         for (; n > 0; n--) {
           TValue *val = ra+n;
-          setobj2t(L, luaH_setint(L, h, last--), val);
+          luaH_setint(L, h, last--, val);
           luaC_barrierback(L, obj2gco(h), val);
         }
         L->top = ci->top;  /* correct top (in case of previous open call) */