I typed C-w. Emacs crashed. This was in "emacs -Q" (master), in a message-mode buffer. Backtraces: (gdb) bt #0 0x00007ff9ab4cc803 in KERNELBASE!DebugBreak () from C:\WINDOWS\System32\KernelBase.dll #1 0x00000004003862d9 in emacs_abort () at w32fns.c:10802 #2 0x000000040014afee in terminate_due_to_signal (sig=11, backtrace_limit=40) at emacs.c:401 #3 0x0000000400182aed in handle_fatal_signal (sig=11) at sysdep.c:1790 #4 0x0000000400182ac0 in deliver_thread_signal (sig=11, handler=0x400182ad5 ) at sysdep.c:1764 #5 0x0000000400182b29 in deliver_fatal_thread_signal (sig=11) at sysdep.c:1802 #6 0x000000040043e766 in _gnu_exception_handler (exception_data=0xbf2d40) at E:/mingwbuild/mingw-w64-crt-git/src/mingw-w64/mingw-w64-crt/crt/crt_handler.c:223 #7 0x00007ff9abb58048 in msvcrt!__C_specific_handler () from C:\WINDOWS\System32\msvcrt.dll #8 0x00007ff9adb735df in ntdll!.chkstk () from C:\WINDOWS\SYSTEM32\ntdll.dll #9 0x00007ff9adb220a9 in ntdll!RtlRaiseException () from C:\WINDOWS\SYSTEM32\ntdll.dll #10 0x00007ff9adb7224e in ntdll!KiUserExceptionDispatcher () from C:\WINDOWS\SYSTEM32\ntdll.dll #11 0x0000000400217205 in re_match_2_internal (bufp=0x4008fdef0 , string1=0x1600000 "MZ\220", size1=179, string2=0x1601569 "", size2=3470, pos=1589, regs=0x400790778 , stop=1931) at regex-emacs.c:4940 #12 0x000000040021108a in rpl_re_search_2 (bufp=0x4008fdef0 , str1=0x1600000 "MZ\220", size1=179, str2=0x1601569 "", size2=3470, startpos=1589, range=342, regs=0x400790778 , stop=1931) at regex-emacs.c:3373 #13 0x00000004001fb4b4 in search_buffer_re (string=XIL(0xe420e4), pos=1426, pos_byte=1426, lim=1932, lim_byte=1932, n=1, trt=XIL(0), inverse_trt=XIL(0), posix=false) at search.c:1244 #14 0x00000004001fc373 in search_buffer (string=XIL(0xe420e4), pos=1426, pos_byte=1426, lim=1932, lim_byte=1932, n=1, RE=1, trt=XIL(0), inverse_trt=XIL(0), posix=false) at search.c:1506 #15 0x00000004001facb7 in search_command (string=XIL(0xe420e4), bound=make_fixnum(1932), noerror=XIL(0x30), count=XIL(0), direction=1, RE=1, posix=false) at search.c:1048 #16 0x00000004001fe4ac in Fre_search_forward (regexp=XIL(0xe420e4), bound=make_fixnum(1932), noerror=XIL(0x30), count=XIL(0)) at search.c:2277 #17 0x0000000400275106 in funcall_subr (subr=0x40079c480 , numargs=3, args=0xbf5500) at eval.c:2875 #18 0x0000000400274ca2 in Ffuncall (nargs=4, args=0xbf54f8) at eval.c:2794 #19 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x8f35554), vector=XIL(0x8ec9335), maxdepth=make_fixnum(9), args_template=make_fixnum(257), nargs=1, args=0xbf5a70) at bytecode.c:633 #20 0x00000004002756b5 in funcall_lambda (fun=XIL(0x8ec7fc5), nargs=1, arg_vector=0xbf5a68) at eval.c:2989 #21 0x0000000400274ce6 in Ffuncall (nargs=2, args=0xbf5a60) at eval.c:2796 #22 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x4164334), vector=XIL(0x415dc25), maxdepth=make_fixnum(25), args_template=make_fixnum(770), nargs=3, args=0xbf6118) at bytecode.c:633 #23 0x00000004002756b5 in funcall_lambda (fun=XIL(0x415dbf5), nargs=3, arg_vector=0xbf6100) at eval.c:2989 #24 0x0000000400274ce6 in Ffuncall (nargs=4, args=0xbf60f8) at eval.c:2796 #25 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x428e534), vector=XIL(0x415d1d5), maxdepth=make_fixnum(14), args_template=make_fixnum(771), nargs=3, args=0xbf66a0) at bytecode.c:633 #26 0x00000004002756b5 in funcall_lambda (fun=XIL(0x415d1a5), nargs=3, arg_vector=0xbf6688) at eval.c:2989 #27 0x0000000400274ce6 in Ffuncall (nargs=4, args=0xbf6680) at eval.c:2796 #28 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x428e734), vector=XIL(0x415d10d), maxdepth=make_fixnum(7), args_template=make_fixnum(770), nargs=2, args=0xbf6b68) at bytecode.c:633 #29 0x00000004002756b5 in funcall_lambda (fun=XIL(0x415d0dd), nargs=2, arg_vector=0xbf6b58) at eval.c:2989 #30 0x0000000400274ce6 in Ffuncall (nargs=3, args=0xbf6b50) at eval.c:2796 #31 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x42891b4), vector=XIL(0x902b8d5), maxdepth=make_fixnum(10), args_template=make_fixnum(257), nargs=1, args=0xbf72b0) at bytecode.c:633 #32 0x00000004002756b5 in funcall_lambda (fun=XIL(0x902b925), nargs=1, arg_vector=0xbf72a8) at eval.c:2989 #33 0x0000000400274ce6 in Ffuncall (nargs=2, args=0xbf72a0) at eval.c:2796 #34 0x000000040027421f in run_hook_wrapped_funcall (nargs=2, args=0xbf72a0) at eval.c:2531 #35 0x00000004002744a1 in run_hook_with_args (nargs=2, args=0xbf72a0, funcall=0x4002741d6 ) at eval.c:2612 #36 0x0000000400274271 in Frun_hook_wrapped (nargs=2, args=0xbf72a0) at eval.c:2546 #37 0x0000000400274f9b in funcall_subr (subr=0x4007a0480 , numargs=2, args=0xbf72a0) at eval.c:2847 #38 0x0000000400274ca2 in Ffuncall (nargs=3, args=0xbf7298) at eval.c:2794 #39 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x428929c), vector=XIL(0x428913d), maxdepth=make_fixnum(19), args_template=make_fixnum(514), nargs=2, args=0xbf7810) at bytecode.c:633 #40 0x00000004002756b5 in funcall_lambda (fun=XIL(0x428910d), nargs=2, arg_vector=0xbf7800) at eval.c:2989 #41 0x0000000400274ce6 in Ffuncall (nargs=3, args=0xbf77f8) at eval.c:2796 #42 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x4289384), vector=XIL(0x4288e4d), maxdepth=make_fixnum(27), args_template=make_fixnum(512), nargs=2, args=0xbf7e48) at bytecode.c:633 #43 0x00000004002756b5 in funcall_lambda (fun=XIL(0x4288e1d), nargs=2, arg_vector=0xbf7e38) at eval.c:2989 #44 0x0000000400274ce6 in Ffuncall (nargs=3, args=0xbf7e30) at eval.c:2796 #45 0x00000004002e2faa in exec_byte_code (bytestr=XIL(0x429230c), vector=XIL(0x4291f25), maxdepth=make_fixnum(12), args_template=make_fixnum(257), nargs=1, args=0xbf83d0) at bytecode.c:633 #46 0x00000004002756b5 in funcall_lambda (fun=XIL(0x4291ef5), nargs=1, arg_vector=0xbf83c8) at eval.c:2989 #47 0x0000000400274ce6 in Ffuncall (nargs=2, args=0xbf83c0) at eval.c:2796 #48 0x00000004002716e7 in internal_condition_case_n (bfun=0x400274b02 , nargs=2, args=0xbf83c0, handlers=XIL(0x30), hfun=0x40003ae7e ) at eval.c:1435 #49 0x000000040003b093 in safe__call (inhibit_quit=false, nargs=2, func=XIL(0xfffffffc0398b140), ap=0xbf8488 "\001") at xdisp.c:2740 #50 0x000000040003b0f9 in safe_call (nargs=2, func=XIL(0xfffffffc0398b140)) at xdisp.c:2755 #51 0x000000040003b12c in safe_call1 (fn=XIL(0xfffffffc0398b140), arg=make_fixnum(1426)) at xdisp.c:2766 #52 0x000000040003e0a7 in handle_fontified_prop (it=0xbf9cc0) at xdisp.c:4062 #53 0x000000040003ce05 in handle_stop (it=0xbf9cc0) at xdisp.c:3590 #54 0x000000040004a47c in next_element_from_buffer (it=0xbf9cc0) at xdisp.c:8635 #55 0x0000000400046af0 in get_next_display_element (it=0xbf9cc0) at xdisp.c:7229 #56 0x0000000400072313 in display_line (it=0xbf9cc0, cursor_vpos=40) at xdisp.c:21903 #57 0x0000000400066a2c in try_window (window=XIL(0x4a32ba5), pos=..., flags=1) at xdisp.c:17953 #58 0x00000004000643ee in redisplay_window (window=XIL(0x4a32ba5), just_this_one_p=true) at xdisp.c:17401 #59 0x000000040005d189 in redisplay_window_1 (window=XIL(0x4a32ba5)) at xdisp.c:15136 #60 0x000000040027155d in internal_condition_case_1 (bfun=0x40005d14a , arg=XIL(0x4a32ba5), handlers=XIL(0x4365af3), hfun=0x40005d0bf ) at eval.c:1379 #61 0x000000040005c43b in redisplay_internal () at xdisp.c:14706 #62 0x000000040005a0fb in redisplay () at xdisp.c:13818 #63 0x00000004001590c8 in read_char (commandflag=1, map=XIL(0xe27813), prev_event=XIL(0), used_mouse_menu=0xbff22f, end_time=0x0) at keyboard.c:2472 #64 0x0000000400166a9c in read_key_sequence (keybuf=0xbff460, prompt=XIL(0), dont_downcase_last=false, can_return_switch_frame=true, fix_current_buffer=true, prevent_redisplay=false) at keyboard.c:9125 #65 0x00000004001565fb in command_loop_1 () at keyboard.c:1345 #66 0x00000004002714a3 in internal_condition_case (bfun=0x400156121 , handlers=XIL(0x90), hfun=0x4001556f9 ) at eval.c:1355 #67 0x0000000400155d7f in command_loop_2 (ignore=XIL(0)) at keyboard.c:1091 #68 0x0000000400270d47 in internal_catch (tag=XIL(0xdda0), func=0x400155d4d , arg=XIL(0)) at eval.c:1116 #69 0x0000000400155cd3 in command_loop () at keyboard.c:1070 #70 0x0000000000000000 in ?? () Backtrace stopped: previous frame inner to this frame (corrupt stack?) Lisp Backtrace: "re-search-forward" (0xbf5500) 0x8ec7fc0 PVEC_COMPILED "font-lock-fontify-keywords-region" (0xbf6100) "font-lock-default-fontify-region" (0xbf6688) "font-lock-fontify-region" (0xbf6b58) 0x902b920 PVEC_COMPILED "run-hook-wrapped" (0xbf72a0) "jit-lock--run-functions" (0xbf7800) "jit-lock-fontify-now" (0xbf7e38) "jit-lock-function" (0xbf83c8) "redisplay_internal (C function)" (0x0) In GNU Emacs 27.0.50 (build 12, x86_64-w64-mingw32) of 2019-10-01 built on MACHINE Repository revision: 72dec8539ea7a0d2fd28bf02abb2d55b329b813f Repository branch: buster Windowing system distributor 'Microsoft Corp.', version 10.0.18890 System Description: Microsoft Windows 10 Pro (v10.0.1903.18890.1000) Recent messages: For information about GNU Emacs and the GNU system, type C-h C-a. Configured using: 'configure --config-cache --with-modules --without-pop --without-dbus --without-gconf --without-gsettings 'CFLAGS=-O0 -ggdb3'' Configured features: XPM JPEG TIFF GIF PNG RSVG SOUND NOTIFY W32NOTIFY ACL GNUTLS LIBXML2 HARFBUZZ ZLIB TOOLKIT_SCROLL_BARS MODULES THREADS JSON PDUMPER LCMS2 GMP Important settings: value of $LANG: ENG locale-coding-system: cp1252 Major mode: Lisp Interaction Minor modes in effect: tooltip-mode: t global-eldoc-mode: t eldoc-mode: t electric-indent-mode: t mouse-wheel-mode: t tool-bar-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-composition-mode: t auto-encryption-mode: t auto-compression-mode: t line-number-mode: t transient-mark-mode: t Load-path shadows: None found. Features: (shadow sort mail-extr emacsbug message rmc puny dired dired-loaddefs format-spec rfc822 mml easymenu mml-sec password-cache epa derived epg epg-config gnus-util rmail rmail-loaddefs text-property-search time-date subr-x seq byte-opt gv bytecomp byte-compile compile comint ansi-color ring cconv mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util mail-prsvr mail-utils tooltip eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel dos-w32 ls-lisp disp-table term/w32-win w32-win w32-vars term/common-win tool-bar dnd fontset image regexp-opt fringe tabulated-list replace newcomment text-mode elisp-mode lisp-mode prog-mode register page menu-bar rfn-eshadow isearch timer select scroll-bar mouse jit-lock font-lock syntax facemenu font-core term/tty-colors frame cl-generic cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese composite charscript charprop case-table epa-hook jka-cmpr-hook help simple abbrev obarray minibuffer cl-preloaded nadvice loaddefs button faces cus-face macroexp files text-properties overlay sha1 md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote threads w32notify w32 lcms2 multi-tty make-network-process emacs) Memory information: ((conses 16 51879 6844) (symbols 48 6571 1) (strings 32 18260 1549) (string-bytes 1 571256) (vectors 16 10618) (vector-slots 8 133305 9570) (floats 8 23 199) (intervals 56 220 7) (buffers 992 11))