🚀 go-pugleaf

In GNU Emacs 19.26.2 (i486-esix5r4, X toolkit) of Fri Sep  9 1994 on ptdca3

I am getting segmentation faults with 19.26 that did not occur in 19.25.
I am using X11R5 on esix svr4.

Here is a recipe to create the problem:

$ cd <emacs src directory>
$ ./emacs -q

find-file xterm.c
font-lock-mode

During the regex parsing, emacs locks up.  Doing exactly the same
procedure under emacs 19.25 worked properly.

Here is the output from running under sdb:

[emacs/emacs-19.26/src] sdb -s 14 ./emacs
can't find memory segment for r_debug (0x32252063)!
666:      Vcommand_history = Qnil;
*r -q
SIGNALED 11 process 4252 function alloca() in alloca.c
216:        ((header *) new)->h.next = last_alloca_header;
*t
alloca(size=20) [alloca.c:216]
re_match_2_internal(bufp=0x814c4e4,string1="/* X Communication module for termin
als which understand the X protocol.\n   Copyright (C) 1989, 1993, 1994 Free Sof
tware Foundation, Inc.\n\nThis file is part of GNU Emacs.\n\nGNU Emacs is free s
oftware; you can redistribute it and/or modify\nit under the terms of the GNU Ge
neral Public License as published by\nthe Free Software Foundation; either versi
on 2, or (at your option)\nany later version.\n\nGNU Emacs is distributed in the
 hope that it will be useful,\nbut WITHOUT ANY WARRANTY; without even the implie
d warranty of\nMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\nGN
U General Public License for more details.\n\nYou should have received a copy of
 the GNU General Public License\nalong with GNU Emacs; see the file COPYING.  If
 not, write to\nthe Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 USA.  */\n\n/* Xt features made by Fred Pierresteguy.  */\n\n/* On 4.3 these lo
se if they come after xterm.h.  */\n/* On HP-UX 8.0 signal.h loses if it comes a
fter",size1=176912,string2="\365\003",size2=0,pos=88142,regs=0x81471b8,stop=1769
12)     [regex.c:3482]
re_search_2(bufp=0x814c4e4,string1="/* X Communication module for terminals whic
h understand the X protocol.\n   Copyright (C) 1989, 1993, 1994 Free Software Fo
undation, Inc.\n\nThis file is part of GNU Emacs.\n\nGNU Emacs is free software;
 you can redistribute it and/or modify\nit under the terms of the GNU General Pu
blic License as published by\nthe Free Software Foundation; either version 2, or
 (at your option)\nany later version.\n\nGNU Emacs is distributed in the hope th
at it will be useful,\nbut WITHOUT ANY WARRANTY; without even the implied warran
ty of\nMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\nGNU Genera
l Public License for more details.\n\nYou should have received a copy of the GNU
 General Public License\nalong with GNU Emacs; see the file COPYING.  If not, wr
ite to\nthe Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  *
/\n\n/* Xt features made by Fred Pierresteguy.  */\n\n/* On 4.3 these lose if th
ey come after xterm.h.  */\n/* On HP-UX 8.0 signal.h loses if it comes after",si
ze1=176912,string2="\365\003",size2=0,startpos=88142,range=88770,regs=0x81471b8,
stop=176912)    [regex.c:3190]
search_buffer(string=51986568,pos=1,lim=176913,n=1,RE=1,trt=0,inverse_trt=0)
[search.c:720]
search_command(string=51986568,bound=176913,noerror=18157016,count=18156976,dire
ction=1,RE=1)   [search.c:563]
Fre_search_forward(regexp=51986568,bound=176913,noerror=18157016,count=18156976)
        [search.c:1157]
Ffuncall(nargs=4,args=0x81b0f00)        [eval.c:2067]
Fbyte_code(bytestr=51981740,vector=68880176,maxdepth=14)        [bytecode.c:422]
funcall_lambda(fun=102501320,nargs=3,arg_vector=0x81a2378)      [eval.c:2231]
Ffuncall(nargs=4,args=0x81a2374)        [eval.c:2097]
Fbyte_code(bytestr=51983584,vector=68880580,maxdepth=4) [bytecode.c:422]
funcall_lambda(fun=102056760,nargs=0,arg_vector=0x8167658)      [eval.c:2231]
Ffuncall(nargs=1,args=0x8167654)        [eval.c:2097]
Fbyte_code(bytestr=51982340,vector=68880460,maxdepth=4) [bytecode.c:422]
funcall_lambda(fun=102465788,nargs=1,arg_vector=0x81b02f8)      [eval.c:2231]
Ffuncall(nargs=2,args=0x81b02f4)        [eval.c:2097]
Fcall_interactively(function=18317628,record=18157016)  [callint.c:586]
Fcommand_execute(cmd=18317628,record=18157016)  [keyboard.c:5289]
Fexecute_extended_command(prefixarg=18156976)   [keyboard.c:5366]
Ffuncall(nargs=2,args=0x81af034)        [eval.c:2056]
Fcall_interactively(function=18185308,record=18156976)  [callint.c:586]
Fcommand_execute(cmd=18185308,record=18156976)  [keyboard.c:5289]
command_loop_1()        [keyboard.c:1230]
internal_condition_case(0x8074278,0x1150edc,0x8073e5c)  [eval.c:1096]
command_loop_2(0x1150db0)       [keyboard.c:879]
internal_catch(tag=18157256,0x8074138,0x1150db0)        [eval.c:886]
command_loop()  [keyboard.c:859]
recursive_edit_1()      [keyboard.c:694]
Frecursive_edit()       [keyboard.c:736]
main(argc=1,argv=0x80475fc,envp=0x8047650)      [emacs.c:762]
_start()
*