Original patch here: http://www.sxemacs.org/list-archives/html/sxemacs-patches/2007-01/msg0000... This varies quite a bit from that patch, since the 21.5 code is significantly different. src/ChangeLog addition: 2007-05-24 Aidan Kehoe <kehoea(a)parhasard.net&gt; * free-hook.c (check_free): * lisp.h: * lisp.h (xfree): Inspired by some of Sebastian Freundt's SXEmacs work, use a 64-bit constant on 64-bit platforms when making sure pointers haven't been freed twice. XEmacs Trunk source patch: Diff command: cvs -q diff -Nu Files affected: src/lisp.h =================================================================== RCS src/free-hook.c =================================================================== RCS Index: src/free-hook.c =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/free-hook.c,v retrieving revision 1.13 diff -u -u -r1.13 free-hook.c --- src/free-hook.c 2005/01/26 10:36:08 1.13 +++ src/free-hook.c 2007/05/24 07:35:03 ＠＠ -179,6 +179,8 ＠＠ / sizeof (long); unsigned long i; + /* Not using the DEADBEEF_CONSTANT #define, since we don't know + * that allocation sizes will be multiples of eight. */ for (i = 0; i < long_length; i++) ((unsigned long *) ptr)[i] = 0xdeadbeef; } Index: src/lisp.h =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/lisp.h,v retrieving revision 1.144 diff -u -u -r1.144 lisp.h --- src/lisp.h 2006/11/05 22:31:44 1.144 +++ src/lisp.h 2007/05/24 07:35:05 ＠＠ -250,6 +250,14 ＠＠ typedef unsigned long uintptr_t; #endif +#if SIZEOF_VOID_P == 8 +#define DEADBEEF_CONSTANT 0xCAFEBABEDEADBEEF +#elif SIZEOF_VOID_P == 4 +#define DEADBEEF_CONSTANT 0xDEADBEEF +#else +#error "What size are your pointers, really?" +#endif /* SIZEOF_VOID_P == 8 */ + /* ---------------------- definition of EMACS_INT --------------------- */ /* EMACS_INT is the underlying integral type into which a Lisp_Object must fit. ＠＠ -1084,7 +1092,7 ＠＠ #define xfree(lvalue, type) do \ { \ xfree_1 (lvalue); \ - VOIDP_CAST (lvalue) = (void *) 0xDEADBEEF; \ + VOIDP_CAST (lvalue) = (void *) DEADBEEF_CONSTANT; \ } while (0) #else #define xfree(lvalue,type) xfree_1 (lvalue) -- On the quay of the little Black Sea port, where the rescued pair came once more into contact with civilization, Dobrinton was bitten by a dog which was assumed to be mad, though it may only have been indiscriminating. (Saki) _______________________________________________ XEmacs-Patches mailing list XEmacs-Patches(a)xemacs.org http://calypso.tux.org/cgi-bin/mailman/listinfo/xemacs-patches