diff -up grep-2.5.3/src/search.c.bz479152 grep-2.5.3/src/search.c

--- grep-2.5.3/src/search.c.bz479152	2009-01-08 09:57:12.000000000 +0100

+++ grep-2.5.3/src/search.c	2009-01-08 09:58:57.000000000 +0100

@@ -757,7 +757,7 @@ EXECUTE_FCT(Fexecute)

   const char *last_char = NULL;

 #endif /* MBS_SUPPORT */

-  for (beg = start_ptr ? start_ptr : buf; beg <= buf + size; beg++)

+  for (beg = start_ptr ? start_ptr : buf; beg < buf + size; beg++)

     {

       size_t offset = kwsexec (kwset, beg, buf + size - beg, &kwsmatch);

       if (offset == (size_t) -1)