From f52f357a5576aad0794e4c46b86bba5c75ddcf3d Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 7 Jul 2003 10:37:56 -0300
Subject: [PATCH] correct handling when a thread turns on line hooks in another
 thread

---
 lvm.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/lvm.c b/lvm.c
index 1905b8d1..b8ac9ec8 100644
--- a/lvm.c
+++ b/lvm.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lvm.c,v 1.286 2003/05/13 20:15:59 roberto Exp roberto $
+** $Id: lvm.c,v 1.287 2003/05/14 12:09:12 roberto Exp roberto $
 ** Lua virtual machine
 ** See Copyright Notice in lua.h
 */
@@ -76,13 +76,15 @@ static void traceexec (lua_State *L) {
   if (mask & LUA_MASKLINE) {
     CallInfo *ci = L->ci;
     Proto *p = ci_func(ci)->l.p;
-    int newline = getline(p, pcRel(*ci->u.l.pc, p));
+    int pc = pcRel(*ci->u.l.pc, p);
+    int newline = getline(p, pc);
     if (!L->hookinit) {
       luaG_inithooks(L);
-      return;
+      if (pc != 0)  /* not function start? */
+        return;  /* begin tracing on next line */
     }
     lua_assert(ci->state & CI_HASFRAME);
-    if (pcRel(*ci->u.l.pc, p) == 0)  /* tracing may be starting now? */
+    if (pc == 0)  /* function may be starting now? */
       ci->u.l.savedpc = *ci->u.l.pc;  /* initialize `savedpc' */
     /* calls linehook when enters a new line or jumps back (loop) */
     if (*ci->u.l.pc <= ci->u.l.savedpc ||