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-mbmemcasecmp1.sh
tests/test-mbmemcasecmp2.sh
tests/test-mbmemcasecmp3.sh
tests/test-mbmemcasecmp.c
tests/test-mbmemcasecmp.h
tests/macros.h
m4/locale-fr.m4
m4/locale-tr.m4
m4/codeset.m4

Depends-on:
stdbool
setlocale

configure.ac:
gt_LOCALE_FR
gt_LOCALE_FR_UTF8
gt_LOCALE_TR_UTF8

Makefile.am:
TESTS += test-mbmemcasecmp1.sh test-mbmemcasecmp2.sh test-mbmemcasecmp3.sh
TESTS_ENVIRONMENT += \
  LOCALE_FR='@LOCALE_FR@' \
  LOCALE_FR_UTF8='@LOCALE_FR_UTF8@' \
  LOCALE_TR_UTF8='@LOCALE_TR_UTF8@'
check_PROGRAMS += test-mbmemcasecmp