From 4e43741943780b6fc21d2e93d1e99812778cad24 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 30 Mar 2009 15:39:20 -0300
Subject: [PATCH] in 'lua_call', avoid preparing a continuation when thread
 cannot yield.

---
 lapi.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/lapi.c b/lapi.c
index eb4fe4f3..9b1f2462 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.71 2009/03/10 17:14:37 roberto Exp roberto $
+** $Id: lapi.c,v 2.72 2009/03/23 14:26:12 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -779,14 +779,14 @@ LUA_API void lua_callk (lua_State *L, int nargs, int nresults, int ctx,
   api_checknelems(L, nargs+1);
   checkresults(L, nargs, nresults);
   func = L->top - (nargs+1);
-  if (k != NULL) {
-    L->ci->u.c.k = k;
-    L->ci->u.c.ctx = ctx;
-    L->ci->callstatus |= CIST_CTX;
-    luaD_call(L, func, nresults, 1);
+  if (k != NULL && L->nny == 0) {  /* need to prepare continuation? */
+    L->ci->u.c.k = k;  /* save continuation */
+    L->ci->u.c.ctx = ctx;  /* save context */
+    L->ci->callstatus |= CIST_CTX;  /* mark that call has context */
+    luaD_call(L, func, nresults, 1);  /* do the call */
   }
-  else
-    luaD_call(L, func, nresults, 0);
+  else  /* no continuation or no yieldable */
+    luaD_call(L, func, nresults, 0);  /* just do the call */
   adjustresults(L, nresults);
   lua_unlock(L);
 }