The reproducer does the ulimit itself, that's why you're getting a core.
The example code in 1726372 specifically does:
corelimit.rlim_cur = RLIM_INFINITY; corelimit.rlim_max = RLIM_INFINITY; setrlimit(RLIMIT_CORE, &corelimit);
Which is equivalent to "ulimit -c unlimited"
The reproducer does the ulimit itself, that's why you're getting a core.
The example code in 1726372 specifically does:
corelimit. rlim_cur = RLIM_INFINITY; rlim_max = RLIM_INFINITY; RLIMIT_ CORE, &corelimit);
corelimit.
setrlimit(
Which is equivalent to "ulimit -c unlimited"