4 files changed, 17 insertions, 6 deletions
diff --git a/lapi.h b/lapi.h
index 5a4206f1..f48d14fd 100644
--- a/lapi.h
+++ b/lapi.h
@@ -11,12 +11,22 @@
 #include "llimits.h"
 #include "lstate.h"
+/* Increments 'L->top', checking for stack overflows */
 #define api_incr_top(L)   {L->top++; api_check(L, L->top <= L->ci->top, \
                                "stack overflow");}
+/*
+** If a call returns too many multiple returns, the callee may not have
+** stack space to accomodate all results. In this case, this macro
+** increases its stack space ('L->ci->top').
+*/
 #define adjustresults(L,nres) \
    { if ((nres) <= LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; }
+/* Ensure the stack has at least 'n' elements */
 #define api_checknelems(L,n)    api_check(L, (n) < (L->top - L->ci->func), \
                                  "not enough elements in the stack")
diff --git a/lparser.c b/lparser.c
index b70c609e..7447222b 100644
--- a/lparser.c
+++ b/lparser.c
@@ -694,9 +694,10 @@ static Proto *addprototype (LexState *ls) {
 /*
 ** codes instruction to create new closure in parent function.
-** The OP_CLOSURE instruction must use the last available register,
+** The OP_CLOSURE instruction uses the last available register,
 ** so that, if it invokes the GC, the GC knows which registers
 ** are in use at that time.
 */
 static void codeclosure (LexState *ls, expdesc *v) {
  FuncState *fs = ls->fs->prev;
diff --git a/lvm.c b/lvm.c
index d9bd0ab3..26477c2c 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1258,7 +1258,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
        if (TESTARG_k(i))
          c += GETARG_Ax(*pc) * (MAXARG_C + 1);
        pc++;  /* skip extra argument */
-        L->top = ci->top;  /* correct top in case of GC */
+        L->top = ra + 1;  /* correct top in case of emergency GC */
        t = luaH_new(L);  /* memory allocation */
        sethvalue2s(L, ra, t);
        if (b != 0 || c != 0)
@@ -1478,7 +1478,6 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
        vmbreak;
      }
      vmcase(OP_CLOSE) {
-        L->top = ra + 1;  /* everything is free after this slot */
        Protect(luaF_close(L, ra, LUA_OK));
        vmbreak;
      }
@@ -1755,7 +1754,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
        /* push function, state, and control variable */
        memcpy(ra + 4, ra, 3 * sizeof(*ra));
        L->top = ra + 4 + 3;
-        Protect(luaD_call(L, ra + 4, GETARG_C(i)));  /* do the call */
+        ProtectNT(luaD_call(L, ra + 4, GETARG_C(i)));  /* do the call */
        updatestack(ci);  /* stack may have changed */
        i = *(pc++);  /* go to next instruction */
        lua_assert(GET_OPCODE(i) == OP_TFORLOOP && ra == RA(i));
@@ -1776,7 +1775,7 @@ void luaV_execute (lua_State *L, CallInfo *ci) {
        if (n == 0)
          n = cast_int(L->top - ra) - 1;  /* get up to the top */
        else
-          L->top = ci->top;  /* correct top in case of GC */
+          L->top = ci->top;  /* correct top in case of emergency GC */
        last += n;
        if (TESTARG_k(i)) {
          last += GETARG_Ax(*pc) * (MAXARG_C + 1);
diff --git a/testes/nextvar.lua b/testes/nextvar.lua
index a7fe625e..9d919631 100644
--- a/testes/nextvar.lua
+++ b/testes/nextvar.lua
@@ -671,7 +671,8 @@ collectgarbage()
 local function f (n, p)
  local t = {}; for i=1,p do t[i] = i*10 end
-  return function (_,n)
+  return function (_, n, ...)
+           assert(select("#", ...) == 0)  -- no extra arguments
           if n > 0 then
             n = n-1
             return n, table.unpack(t)