tighter tests for stack overflow

1 files changed, 10 insertions, 7 deletions

diff --git a/lgc.c b/lgc.c
index 94d801ab..6beaa55b 100644
--- a/lgc.c
+++ b/lgc.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lgc.c,v 2.9 2004/08/24 20:12:06 roberto Exp roberto $
+** $Id: lgc.c,v 2.10 2004/08/30 13:44:44 roberto Exp roberto $
 ** Garbage Collector
 ** See Copyright Notice in lua.h
 */
@@ -239,14 +239,17 @@ static void traverseclosure (global_State *g, Closure *cl) {
 
 
 static void checkstacksizes (lua_State *L, StkId max) {
-  int used = L->ci - L->base_ci;  /* number of `ci' in use */
-  if (4*used < L->size_ci && 2*BASIC_CI_SIZE < L->size_ci)
+  int ci_used = L->ci - L->base_ci;  /* number of `ci' in use */
+  int s_used = max - L->stack;  /* part of stack in use */
+  if (L->size_ci > LUA_MAXCALLS)  /* handling overflow? */
+    return;  /* do not touch the stacks */
+  if (4*ci_used < L->size_ci && 2*BASIC_CI_SIZE < L->size_ci)
     luaD_reallocCI(L, L->size_ci/2);  /* still big enough... */
-  else condhardstacktests(luaD_reallocCI(L, L->size_ci));
-  used = max - L->stack;  /* part of stack in use */
-  if (4*used < L->stacksize && 2*(BASIC_STACK_SIZE+EXTRA_STACK) < L->stacksize)
+  condhardstacktests(luaD_reallocCI(L, ci_used + 1));
+  if (4*s_used < L->stacksize &&
+      2*(BASIC_STACK_SIZE+EXTRA_STACK) < L->stacksize)
     luaD_reallocstack(L, L->stacksize/2);  /* still big enough... */
-  else condhardstacktests(luaD_reallocstack(L, L->stacksize));
+  condhardstacktests(luaD_reallocstack(L, s_used));
 }