Added check whether malloc(0) returns NULL or not.
diff --git a/configure b/configure
index 83418cf..41dad21 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
#! /bin/sh
-# From configure.in Revision: 1.53
+# From configure.in Revision: 1.54
# Guess values for system-dependent variables and create Makefiles.
# Generated automatically using autoconf version 2.12
@@ -3666,6 +3666,59 @@
echo "$ac_t""$ac_cv_func_getopt" 1>&6
test $ac_cv_func_getopt = no && LIBOBJS="$LIBOBJS getopt.o"
+# check whether malloc(0) returns NULL or not
+
+echo $ac_n "checking what malloc(0) returns""... $ac_c" 1>&6
+echo "configure:3673: checking what malloc(0) returns" >&5
+if eval "test \"`echo '$''{'ac_cv_malloc_zero'+set}'`\" = set"; then
+ echo $ac_n "(cached) $ac_c" 1>&6
+else
+ if test "$cross_compiling" = yes; then
+ { echo "configure: error: can not run test program while cross compiling" 1>&2; exit 1; }
+else
+ cat > conftest.$ac_ext <<EOF
+#line 3681 "configure"
+#include "confdefs.h"
+#include <stdio.h>
+#ifdef HAVE_STDLIB
+#include <stdlib.h>
+#else
+char *malloc(), *realloc();
+int *free();
+#endif
+main() {
+ char *p;
+ p = malloc(0);
+ if (p == NULL) exit(1);
+ p = realloc(p, 0);
+ if (p == NULL) exit(1);
+ free(p);
+ exit(0);
+}
+EOF
+if { (eval echo configure:3700: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest && (./conftest; exit) 2>/dev/null
+then
+ ac_cv_malloc_zero=nonnull
+else
+ echo "configure: failed program was:" >&5
+ cat conftest.$ac_ext >&5
+ rm -fr conftest*
+ ac_cv_malloc_zero=null
+fi
+rm -fr conftest*
+fi
+
+fi
+
+echo "$ac_t""$ac_cv_malloc_zero" 1>&6
+if test "$ac_cv_malloc_zero" = null
+then
+ cat >> confdefs.h <<\EOF
+#define MALLOC_ZERO_RETURNS_NULL 1
+EOF
+
+fi
+
# generate output files
trap '' 1 2 15
cat > confcache <<\EOF
@@ -3820,6 +3873,7 @@
s%@WANT_SIGFPE_HANDLER@%$WANT_SIGFPE_HANDLER%g
s%@LIBM@%$LIBM%g
s%@LIBC@%$LIBC%g
+s%@MALLOC_ZERO_RETURNS_NULL@%$MALLOC_ZERO_RETURNS_NULL%g
CEOF
EOF