Fixed bug: line hooks in stripped functions

Line-hook handling was accessing debug info. without checking whether
it was present.

1 files changed, 3 insertions, 1 deletions

diff --git a/ldebug.c b/ldebug.c
index 9ff7edeb..8cb00e51 100644
--- a/ldebug.c
+++ b/ldebug.c
@@ -783,11 +783,13 @@ l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
 ** previous instruction 'oldpc'.
 */
 static int changedline (const Proto *p, int oldpc, int newpc) {
+  if (p->lineinfo == NULL)  /* no debug information? */
+    return 0;
   while (oldpc++ < newpc) {
     if (p->lineinfo[oldpc] != 0)
       return (luaG_getfuncline(p, oldpc - 1) != luaG_getfuncline(p, newpc));
   }
-  return 0;  /* no line changes in the way */
+  return 0;  /* no line changes between positions */
 }