Does anyone care about this error at all? I don't do X internals much at all, never have, never really cared to. I've been reporting this occasionally since I first began using 21.2, around -b6 I believe, in the hope that someone might at least have an idea of what add'l info I could dredge up when it happens, to help identify the flaw. Still happens, once or twice a week -- something is misusing a null frame pointer as a consequence of Xt event handling. --karl Program received signal SIGSEGV, Segmentation fault. x_to_emacs_keysym (event=0x7ffff508, simple_p=0) at frame.h:259 259 assert (EQ (FRAME_TYPE (f), sym)); (gdb) bt #0 x_to_emacs_keysym (event=0x7ffff508, simple_p=0) at frame.h:259 #1 0x81b45d4 in x_event_to_emacs_event (x_event=0x7ffff508, emacs_event=0x8967280) at event-Xt.c:999 #2 0x81b67d3 in emacs_Xt_event_handler (wid=0x85b3528, closure=0x0, event=0x7ffff508, continue_to_dispatch=0x7ffff443 "\001ÀtP\b,") at event-Xt.c:2470 #3 0x2ab9cc9f in XtDispatchEventToWidget () #4 0x2ab9d6fd in _XtDefaultDispatcher () #5 0x2ab9d975 in XtDispatchEvent () #6 0x2aba83d5 in XtAppProcessEvent () #7 0x81b6f3f in emacs_Xt_event_pending_p (user_p=1) at event-Xt.c:2626 #8 0x80da8bd in detect_input_pending () at event-stream.c:945 #9 0x80dce11 in Fnext_event (event=146267928, prompt=137162676) at event-stream.c:2237 #10 0x807330e in Fcommand_loop_1 () at cmdloop.c:569 #11 0x807309d in command_loop_1 (dummy=137162676) at cmdloop.c:493 #12 0x8091785 in condition_case_1 (handlers=137162772, bfun=0x807304c <command_loop_1>, barg=137162676, hfun=0x80724d0 <cmd_error>, harg=137162676) at eval.c:1640 #13 0x8073538 in command_loop_2 (dummy=137162676) at cmdloop.c:255 #14 0x8091360 in internal_catch (tag=137236964, func=0x8073504 <command_loop_2>, arg=137162676, threw=0x0) at eval.c:1315 #15 0x8072937 in initial_command_loop (load_me=137162676) at cmdloop.c:304 #16 0x808cfa1 in xemacs_21_2_b19_i686_pc_linux (argc=5, argv=0x7ffff994, envp=0x7ffff9ac, restart=0) at emacs.c:1763 #17 0x808d72d in main (argc=5, argv=0x7ffff994, envp=0x7ffff9ac) at emacs.c:2188 (gdb) list 254 INLINE struct frame * 255 error_check_frame_type (struct frame * f, Lisp_Object sym); 256 INLINE struct frame * 257 error_check_frame_type (struct frame * f, Lisp_Object sym) 258 { 259 assert (EQ (FRAME_TYPE (f), sym)); 260 return f; 261 } 262 # define FRAME_TYPE_DATA(f, type) \ 263 ((struct type##_frame *) (error_check_frame_type (f, Q##type))->frame_data) (gdb) p f $1 = (struct frame *) 0x0 uname -a: Linux beaver.jprc.com 2.2.10-ac10 #1 SMP Tue Jul 13 13:23:27 EDT 1999 i686 unknown ./configure '--with-pop' '--with-mule' '--with-png' XEmacs 21.2-b19 "Shinjuku" configured for `i686-pc-linux'. Where should the build process find the source code? /home/karl/src/x/xemacs-21/xemacs-21.2.19 What installation prefix should install use? /usr/local What operating system and machine description files should XEmacs use? `s/linux.h' and `m/intel386.h' What compiler should XEmacs be built with? gcc -g -O3 -Wall -Wno-switch Should XEmacs use the GNU version of malloc? yes (Using Doug Lea's new malloc from the GNU C Library.) Should XEmacs use the relocating allocator for buffers? yes What window system should XEmacs use? x11 Where do we find X Windows header files? /usr/X11R6/include Where do we find X Windows libraries? /usr/X11R6/lib Compiling in support for XAUTH. Compiling in support for XPM images. Compiling in support for PNG image handling. Compiling in support for (builtin) GIF image handling. Compiling in support for JPEG image handling. Compiling in support for TIFF image handling. Compiling in support for X-Face message headers. Compiling in native sound support. Compiling in support for Berkeley DB. Compiling in support for GNU DBM. Compiling in support for ncurses. Compiling in support for GPM (General Purpose Mouse). Compiling in Mule (multi-lingual) support. Compiling in XIM (X11R5+ I18N input method) support. Using raw Xlib to provide XIM support. Compiling in support for proper WM_COMMAND handling. Using Lucid menubars. Using Lucid scrollbars. Using Athena dialog boxes. Compiling in DSO module support. movemail will use "dot-locking" for locking mail spool files. Using POP for mail access. Compiling in extra code for debugging. WARNING: --------------------------------------------------------- WARNING: Compiling in support for runtime error checking. WARNING: XEmacs will run noticeably more slowly as a result. WARNING: Error checking is on by default for XEmacs beta releases. WARNING: ---------------------------------------------------------