From 617be660158490c7f6558e82d9be2c667c48d9a4 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 6 Dec 1999 10:03:45 -0200
Subject: [PATCH] better control (and error recovery) for begin/end blocks

---
 lapi.c   | 11 ++++-------
 ldo.c    | 10 +++++++---
 lstate.c |  3 ++-
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/lapi.c b/lapi.c
index b4f17b37..953c066e 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 1.61 1999/12/01 19:50:08 roberto Exp roberto $
+** $Id: lapi.c,v 1.62 1999/12/02 16:24:45 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -592,19 +592,16 @@ const char *lua_getobjname (lua_State *L, lua_Object o, const char **name) {
 */
 
 
-#ifndef	MAX_C_BLOCKS
-#define MAX_C_BLOCKS	1000  /* arbitrary limit */
-#endif
-
-
 void lua_beginblock (lua_State *L) {
   luaM_growvector(L, L->Cblocks, L->numCblocks, 1, struct C_Lua_Stack,
-                  "too many nested blocks", MAX_C_BLOCKS);
+                  "too many nested blocks", L->stacksize);
   L->Cblocks[L->numCblocks] = L->Cstack;
   L->numCblocks++;
 }
 
 void lua_endblock (lua_State *L) {
+  if (L->numCblocks <= 0)
+    lua_error(L, "API error - no block to end");
   --L->numCblocks;
   L->Cstack = L->Cblocks[L->numCblocks];
   L->top = L->Cstack.base;
diff --git a/ldo.c b/ldo.c
index 71e19e0f..384bd244 100644
--- a/ldo.c
+++ b/ldo.c
@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 1.56 1999/12/02 16:41:29 roberto Exp roberto $
+** $Id: ldo.c,v 1.57 1999/12/06 11:43:58 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -243,12 +243,13 @@ void lua_error (lua_State *L, const char *s) {
 
 
 /*
-** Execute a protected call. Assumes that function is at L->Cstack.base and
-** parameters are on top of it. Leave nResults on the stack.
+** Execute a protected call. Assumes that function is at Cstack.base and
+** parameters are on top of it.
 */
 int luaD_protectedrun (lua_State *L) {
   struct lua_longjmp myErrorJmp;
   volatile StkId base = L->Cstack.base;
+  volatile int numCblocks = L->numCblocks;
   volatile int status;
   struct lua_longjmp *volatile oldErr = L->errorJmp;
   L->errorJmp = &myErrorJmp;
@@ -262,6 +263,7 @@ int luaD_protectedrun (lua_State *L) {
   else {  /* an error occurred: restore the stack */
     L->Cstack.num = 0;  /* no results */
     L->top = L->Cstack.base = L->Cstack.lua2C = base;
+    L->numCblocks = numCblocks;
     restore_stack_limit(L);
     status = 1;
   }
@@ -276,6 +278,7 @@ int luaD_protectedrun (lua_State *L) {
 static int protectedparser (lua_State *L, ZIO *z, int bin) {
   struct lua_longjmp myErrorJmp;
   volatile StkId base = L->Cstack.base;
+  volatile int numCblocks = L->numCblocks;
   volatile int status;
   TProtoFunc *volatile tf;
   struct lua_longjmp *volatile oldErr = L->errorJmp;
@@ -288,6 +291,7 @@ static int protectedparser (lua_State *L, ZIO *z, int bin) {
   else {  /* an error occurred: restore Cstack and top */
     L->Cstack.num = 0;  /* no results */
     L->top = L->Cstack.base = L->Cstack.lua2C = base;
+    L->numCblocks = numCblocks;
     tf = NULL;
     status = 1;
   }
diff --git a/lstate.c b/lstate.c
index 3306c780..04e7d419 100644
--- a/lstate.c
+++ b/lstate.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.c,v 1.19 1999/12/01 19:50:08 roberto Exp roberto $
+** $Id: lstate.c,v 1.20 1999/12/06 11:41:28 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -99,6 +99,7 @@ void lua_close (lua_State *L) {
   luaM_free(L, L->refArray);
   luaM_free(L, L->Mbuffer);
   luaM_free(L, L->Cblocks);
+  LUA_ASSERT(L, L->numCblocks == 0, "Cblocks still open");
   LUA_ASSERT(L, L->nblocks == 0, "wrong count for nblocks");
   LUA_ASSERT(L, L != lua_state || L->Cstack.lua2C == L->stack, "bad stack");
   LUA_ASSERT(L, L != lua_state || L->Cstack.base == L->stack, "bad stack");