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>

Description:
isnand() function: test for NaN, without requiring libm.

Files:
lib/isnand-nolibm.h
lib/isnand.c
lib/isnan.c
lib/float+.h
m4/exponentd.m4
m4/isnand.m4

Depends-on:
fpieee
memcmp

configure.ac:
gl_FUNC_ISNAND_NO_LIBM
if test $gl_func_isnand_no_libm != yes; then
  AC_LIBOBJ([isnand])
  gl_PREREQ_ISNAND
fi

Makefile.am:

Include:
"isnand-nolibm.h"

License:
LGPL

Maintainer:
Bruno Haible