bug#33169: 26.1; emacs hangs when parenthesis entered in comment

[Paul Vogel]

--text follows this line--
Editing a C header file and trying to add a doxygen-style comment.  Itried to 
enter an open parenthesis in the comment and emacs hangs.  Iwas able to 
replicate this multiple times.  I was able to narrow it downto these lines 
being present in the file:
/* make sure LogStorageTable_t is packed 
*/COMPILE_TIME_ASSERT(sizeof(LogStorageTable_t) == ((sizeof(LogStorageArea_t) * 
                                                  LOG_STORAGE_NUM) +            
                                      sizeof(uint16_t)));
/** hang if open parenthesis is pressed here -> 
Entering a open parenthesis in the above line causes emacs to hang.  Isent 
signal USR2 to the process and got the attached screen shot (sorry,couldn't cut 
and paste from the emacs window after the hang).


In GNU Emacs 26.1 (build 1, x86_64-unknown-cygwin, GTK+ Version 3.22.28) of 
2018-05-28 built on DESKTOPRepository revision: 
d802fa4a0642157d7aff9a9d599785df7604e4d1Windowing system distributor 'The 
Cygwin/X Project', version 11.0.12000000Recent messages:Fill column set to 79 
(was 70)For information about GNU Emacs and the GNU system, type <f1> 
C-a.Making completion list... [2 times]
Configured using: 'configure 
--srcdir=/home/kbrown/src/cygemacs/emacs-26.1-1.x86_64/src/emacs-26.1 
--prefix=/usr --exec-prefix=/usr --localstatedir=/var --sysconfdir=/etc 
--docdir=/usr/share/doc/emacs --htmldir=/usr/share/doc/emacs/html -C 
'CFLAGS=-ggdb -O2 -pipe -Wall -Werror=format-security -Wp,-D_FORTIFY_SOURCE=2 
-fstack-protector-strong --param=ssp-buffer-size=4 
-fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-26.1-1.x86_64/build=/usr/src/debug/emacs-26.1-1
 
-fdebug-prefix-map=/home/kbrown/src/cygemacs/emacs-26.1-1.x86_64/src/emacs-26.1=/usr/src/debug/emacs-26.1-1'
 CPPFLAGS= LDFLAGS='
Configured features:XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND DBUS GSETTINGS 
NOTIFY ACLGNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB 
TOOLKIT_SCROLL_BARSGTK3 X11 THREADS LCMS2
Important settings:  value of $LANG: en_US.UTF-8  locale-coding-system: 
utf-8-unix
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 seq byte-opt 
gvbytecomp byte-compile cconv cl-loaddefs cl-lib dired 
dired-loaddefsformat-spec rfc822 mml easymenu mml-sec password-cache epa 
derived epgepg-config gnus-util rmail rmail-loaddefs mm-decode mm-bodies 
mm-encodemail-parse rfc2231 mailabbrev gmm-utils mailheader sendmail 
rfc2047rfc2045 ietf-drums mm-util mail-prsvr mail-utils elec-pair 
time-datemule-util tooltip eldoc electric uniquify ediff-hook 
vc-hookslisp-float-type mwheel term/x-win x-win term/common-win x-dnd 
tool-bardnd fontset image regexp-opt fringe tabulated-list replace 
newcommenttext-mode elisp-mode lisp-mode prog-mode register page 
menu-barrfn-eshadow isearch timer select scroll-bar mouse jit-lock 
font-locksyntax facemenu font-core term/tty-colors frame cl-generic cham 
georgianutf-8-lang misc-lang vietnamese tibetan thai tai-viet lao 
koreanjapanese eucjp-ms cp51932 hebrew greek romanian slovak czech 
europeanethiopic indian cyrillic chinese composite charscript 
charpropcase-table epa-hook jka-cmpr-hook help simple abbrev obarray 
minibuffercl-preloaded nadvice loaddefs button faces cus-face macroexp 
filestext-properties overlay sha1 md5 base64 format env code-pages mulecustom 
widget hashtable-print-readable backquote dbusbind gfilenotifylcms2 
dynamic-setting system-font-setting font-render-settingmove-toolbar gtk 
x-toolkit x multi-tty make-network-process emacs)
Memory information:((conses 16 95955 10383) (symbols 48 20382 1) (miscs 40 39 
143) (strings 32 28537 1006) (string-bytes 1 747190) (vectors 16 14589) 
(vector-slots 8 495926 9216) (floats 8 50 87) (intervals 56 248 0) (buffers 992 
12))