Here is a crash encountered in xemacs-20.4 The crash occurs whenever I type: /) to complete a regular expression. The stack trace is attached. Alex. (gdb) #0 0xfef969c8 in _libc_kill () #1 0x61c40 in fatal_error_signal (sig=11) at emacs.c:220 #2 <signal handler called> #3 skip_chars (buf=0x272200, forwardp=0, syntaxp=1, string=92, lim=1) at buffer.h:675 #4 0xe7980 in Fskip_syntax_backward (syntax=1612312664, lim=-1608241148, buffer=-1608241148) at search.c:936 #5 0x681b8 in funcall_recording_as (recorded_as=-1608140356, nargs=1, args=0xffbee73c) at eval.c:3235 #6 0x68778 in Ffuncall (nargs=2, args=0xffbee73c) at eval.c:3280 #7 0x4978c in Fbyte_code (bytestr=1612312264, vector=-2145783848, maxdepth=20) at bytecode.c:420 #8 0x694fc in funcall_lambda (fun=538571104, nargs=0, arg_vector=0xffbeea78) at eval.c:3665 #9 0x68724 in funcall_recording_as (recorded_as=-1607843884, nargs=0, args=0xffbeea74) at eval.c:3256 #10 0x68778 in Ffuncall (nargs=1, args=0xffbeea74) at eval.c:3280 #11 0x69b18 in call0 (fn=-1607843884) at eval.c:3991 #12 0x50f50 in internal_self_insert (c1=41, noautofill=0) at cmds.c:428 #13 0x50b78 in Fself_insert_command (arg=41) at cmds.c:322 #14 0x68410 in funcall_recording_as (recorded_as=-1608164112, nargs=1, args=0xffbeecb0) at eval.c:3239 #15 0x68778 in Ffuncall (nargs=2, args=0xffbeecb0) at eval.c:3280 #16 0x4bfa0 in Fcall_interactively (function=-1608164112, record_flag=-1608241148, keys=-1608241148) at callint.c:926 #17 0x66ee0 in Fcommand_execute (cmd=-1608164112, record=-1608241148, keys=-1608241148) at eval.c:2631 #18 0x8716c in execute_command_event (command_builder=0x280cc0, event=540602064) at event-stream.c:4253 #19 0x8774c in Fdispatch_event (event=540602064) at event-stream.c:4547 #20 0x50368 in Fcommand_loop_1 () at cmdloop.c:560 #21 0x50190 in command_loop_1 (dummy=-1608241148) at cmdloop.c:480 #22 0x65bf0 in condition_case_1 (handlers=-1608241068, bfun=0x5016c <command_loop_1>, barg=-1608241148, hfun=0x4faa4 <cmd_error>, harg=-1608241148) at eval.c:1696 #23 0x4fbbc in command_loop_3 () at cmdloop.c:242 #24 0x4fbe4 in command_loop_2 (dummy=-1608241148) at cmdloop.c:253 #25 0x65880 in internal_catch (tag=-1608164192, func=0x4fbd8 <command_loop_2>, arg=-1608241148, threw=0x0) at eval.c:1371 #26 0x4fdf0 in initial_command_loop (load_me=326616) at cmdloop.c:291 #27 0x62e18 in xemacs_20_4_sparc_sun_solaris2_5_1 (argc=2, argv=0xffbef4dc, envp=0xffbef4e8) at emacs.c:1493 #28 0x6351c in main (argc=0, argv=0xffbef4dc, envp=0xffbef4e8) at emacs.c:1849