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:
freadable() function: Determine whether a FILE stream supports reading.

Files:
lib/freadable.h
lib/freadable.c
lib/stdio-impl.h
m4/freadable.m4

Depends-on:
stdbool

configure.ac:
gl_FUNC_FREADABLE
if test $ac_cv_func___freadable = no; then
  AC_LIBOBJ([freadable])
fi

Makefile.am:

Include:
"freadable.h"

License:
LGPL

Maintainer:
Bruno Haible, Eric Blake