crash in newlocale()

[Tony Cook <tony@develop-help.com>]

Hello everyone,

While tracking down a crash in development versions of perl the boostrap
miniperl executable was crashing early in the build process:

$ gdb --args ./miniperl -e0
GNU gdb (GDB) (Cygwin 11.2-1) 11.2
Copyright (C) 2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-pc-cygwin".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./miniperl...
(gdb) b locale.c:1154
Breakpoint 1 at 0x10077db13: file locale.c, line 1154.
(gdb) r
Starting program: /home/tony/dev/perl/git/perl/miniperl -e0
[New Thread 13624.0x1c7c]
[New Thread 13624.0x1978]
[New Thread 13624.0x2958]
[New Thread 13624.0x3374]

Thread 1 "miniperl" hit Breakpoint 1, S_emulate_setlocale_i (my_perl=0x800049910, index=0, new_locale=0x800066628 "en_US.UTF-8", recalc_LC_ALL=-1, line=4026) at locale.c:1154
1154            new_obj = newlocale(mask, new_locale, basis_obj);
(gdb) bt
#0  S_emulate_setlocale_i (my_perl=0x800049910, index=0,
    new_locale=0x800066628 "en_US.UTF-8", recalc_LC_ALL=-1, line=4026)
    at locale.c:1154
#1  0x0000000100783849 in Perl_init_i18nl10n (my_perl=0x800049910, printwarn=1)
    at locale.c:4026
#2  0x0000000100443c80 in perl_construct (my_perl=0x800049910)
    at /home/tony/dev/perl/git/perl/perl.c:447
#3  0x00000001007b7483 in main (argc=2, argv=0xffffcc30, env=0x8000281a0)
    at miniperlmain.c:108
(gdb) p mask
$1 = 4
(gdb) p new_locale
$2 = 0x800066628 "en_US.UTF-8"
(gdb) p basis_obj
$3 = (locale_t) 0x1802b3060 <__C_locale>
(gdb) n

Thread 1 "miniperl" received signal SIGSEGV, Segmentation fault.
0x000000080004a310 in ?? ()
(gdb) bt
#0  0x000000080004a310 in ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
(gdb)

While I get a SEGV from miniperl, a simple reproducer returns a
SIGTRAP:

tony@enceladus ~/dev/perl/git
$ cat newlocale-test.c
#include <locale.h>
#include <stdio.h>

int main() {
  locale_t st = newlocale(LC_ALL_MASK, "C", (locale_t)0);

  locale_t st2 = newlocale(LC_CTYPE_MASK, "en_US.UTF-8", st);
  printf("Done\n");
  return 0;
}
tony@enceladus ~/dev/perl/git
$ gcc -onewlocale-test -g newlocale-test.c

tony@enceladus ~/dev/perl/git
$ gdb ./newlocale-test.exe
GNU gdb (GDB) (Cygwin 11.2-1) 11.2
Copyright (C) 2022 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-pc-cygwin".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<https://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from ./newlocale-test.exe...
(gdb) r
Starting program: /home/tony/dev/perl/git/newlocale-test.exe
[New Thread 9176.0x3a8c]
[New Thread 9176.0x2014]
[New Thread 9176.0x2bc4]
[Thread 9176.0x2014 exited with code 3221225477]
[Thread 9176.0x3a8c exited with code 3221225477]
[Thread 9176.0x2bc4 exited with code 3221225477]

Program terminated with signal SIGTRAP, Trace/breakpoint trap.
The program no longer exists.
(gdb) b main
Breakpoint 1 at 0x10040108d: file newlocale-test.c, line 5.
(gdb) r
Starting program: /home/tony/dev/perl/git/newlocale-test.exe
[New Thread 13668.0x2a7c]
[New Thread 13668.0x15a0]
[New Thread 13668.0x2158]

Thread 1 "newlocale-test" hit Breakpoint 1, main () at newlocale-test.c:5
5         locale_t st = newlocale(LC_ALL_MASK, "C", (locale_t)0);
(gdb) n
7         locale_t st2 = newlocale(LC_CTYPE_MASK, "en_US.UTF-8", st);
(gdb)
[Thread 13668.0x2158 exited with code 3221225477]
[Thread 13668.0x35d0 exited with code 3221225477]
[Thread 13668.0x2a7c exited with code 3221225477]

Program terminated with signal SIGTRAP, Trace/breakpoint trap.
The program no longer exists.
(gdb)

Tony