From b6e2f1a86e2f75c8672b0e9fb8e75438a1f65db9 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 7 Aug 2002 11:24:24 -0300
Subject: [PATCH] small bugs when stack is reallocated

---
 lapi.c | 12 ++++++------
 lvm.c  | 20 +++++++++++---------
 2 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/lapi.c b/lapi.c
index f66ec097..4902be21 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 1.208 2002/08/06 17:06:56 roberto Exp roberto $
+** $Id: lapi.c,v 1.209 2002/08/06 18:54:18 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -747,15 +747,15 @@ LUA_API void *lua_newuserdata (lua_State *L, size_t size) {
 
 
 LUA_API int lua_pushupvalues (lua_State *L) {
-  TObject *func;
+  Closure *func;
   int n, i;
   lua_lock(L);
-  func = (L->ci->base - 1);
-  api_check(L, iscfunction(func));
-  n = clvalue(func)->c.nupvalues;
+  api_check(L, iscfunction(L->ci->base - 1));
+  func = clvalue(L->ci->base - 1);
+  n = func->c.nupvalues;
   luaD_checkstack(L, n + LUA_MINSTACK);
   for (i=0; i<n; i++) {
-    setobj(L->top, &clvalue(func)->c.upvalue[i]);
+    setobj(L->top, &func->c.upvalue[i]);
     L->top++;
   }
   lua_unlock(L);
diff --git a/lvm.c b/lvm.c
index 071b1d0f..3eeb2ff8 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 1.248 2002/07/17 16:25:13 roberto Exp $
+** $Id: lvm.c,v 1.249 2002/08/05 17:36:24 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -385,10 +385,12 @@ StkId luaV_execute (lua_State *L) {
   /* main loop of interpreter */
   for (;;) {
     const Instruction i = *pc++;
-    const StkId ra = RA(i);
+    StkId ra;
     if (L->hookmask >= LUA_MASKLINE &&
         (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE))
       traceexec(L);
+    /* warning!! several calls may realloc the stack and invalidate `ra' */
+    ra = RA(i);
     lua_assert(L->top <= L->stack + L->stacksize && L->top >= L->ci->base);
     lua_assert(L->top == L->ci->top ||
          GET_OPCODE(i) == OP_CALL ||   GET_OPCODE(i) == OP_TAILCALL ||
@@ -544,7 +546,7 @@ StkId luaV_execute (lua_State *L) {
         int b = GETARG_B(i);
         int c = GETARG_C(i);
         luaV_concat(L, c-b+1, c);  /* may change `base' (and `ra') */
-        setobj(base+GETARG_A(i), base+b);
+        setobj(RA(i), base+b);
         luaV_checkGC(L, base+c+1);
         break;
       }
@@ -634,13 +636,13 @@ StkId luaV_execute (lua_State *L) {
           return ra;  /* no: return */
         else {  /* yes: continue its execution (go through) */
           int nresults;
-          lua_assert(ttisfunction(ci->base-1));
-          ci->pc = &pc;  /* function is active again */
-          pc = ci->u.l.savedpc;
-          lua_assert(GET_OPCODE(*(pc-1)) == OP_CALL);
-          nresults = GETARG_C(*(pc-1)) - 1;
+          lua_assert(ttisfunction(ci->base - 1));
+          lua_assert(GET_OPCODE(*(ci->u.l.savedpc - 1)) == OP_CALL);
+          nresults = GETARG_C(*(ci->u.l.savedpc - 1)) - 1;
           luaD_poscall(L, nresults, ra);
           if (nresults >= 0) L->top = L->ci->top;
+          L->ci->pc = &pc;  /* function is active again */
+          pc = L->ci->u.l.savedpc;
           goto retentry;
         }
       }
@@ -670,7 +672,7 @@ StkId luaV_execute (lua_State *L) {
         L->top = ra+5;
         luaD_call(L, ra+2, GETARG_C(i) + 1);
         L->top = L->ci->top;
-        if (ttisnil(ra+2)) pc++;  /* skip jump (break loop) */
+        if (ttisnil(RA(i)+2)) pc++;  /* skip jump (break loop) */
         else dojump(pc, GETARG_sBx(*pc) + 1);  /* else jump back */
         break;
       }