regex: avoid glibc deadlock during configure glibc has a known bug where certain corruptions of the heap can cause malloc to default to printing a debug message that includes a backtrace, but the act of getting the backtrace uses dlopen which in turn calls into malloc, causing a recursive lock ending in deadlock. Thus, when configure is probing for a known glibc heap corruption bug, the overall configure would hang. The solution suggested by glibc developers is to force malloc to quit printing debug messages, which avoids recursive malloc. * m4/regex.m4 (gl_REGEX): Avoid recursive malloc deadlock when glibc bug 15078 in turn triggers bug 16159. Reported by Michal Privoznik. Signed-off-by: Eric Blake <eblake@redhat.com>

Files:
tests/test-posix_spawn3.c
tests/signature.h

Depends-on:
posix_spawn_file_actions_init
posix_spawn_file_actions_addopen
posix_spawn_file_actions_destroy
stdbool
unistd
sys_wait

configure.ac:
AC_EGREP_CPP([notposix], [[
#if defined _MSC_VER || defined __MINGW32__
  notposix
#endif
  ]],
  [posix_spawn_ported=no],
  [posix_spawn_ported=yes])
AM_CONDITIONAL([POSIX_SPAWN_PORTED], [test $posix_spawn_ported = yes])

Makefile.am:
if POSIX_SPAWN_PORTED
TESTS += test-posix_spawn3
check_PROGRAMS += test-posix_spawn3
endif