PR merged https://github.com/pbiering/ipv6calc/pull/51.patch
use LIBS instead of LDFLAGS #962710
fix the failure that might happen with --as-needed
--- a/configure.ac
+++ b/configure.ac
@@ -310,8 +310,8 @@ AC_CHECK_HEADER(md5.h, [
 	AC_MSG_RESULT([libmd/md5.h header file found])
 	AC_CHECK_LIB(md, MD5Init,
 	[
-		LDFLAGS_ORIG="$LDFLAGS"
-		LDFLAGS="-lmd $LDFLAGS"
+		LIBS_ORIG="$LIBS"
+		LIBS="-lmd $LIBS"
 		HAVE_LIBMD_MD5=1
 		AC_CHECK_FUNCS(MD5Init MD5Update MD5Final,
 		[
@@ -319,7 +319,7 @@ AC_CHECK_HEADER(md5.h, [
 			AC_MSG_RESULT([libmd crypto library supports MD5])
 			HAVE_OPENSSL_MD5=0
 		])
-		LDFLAGS="$LDFLAGS_ORIG"
+		LIBS="$LIBS_ORIG"
 
 		if test "$HAVE_LIBMD_MD5" = "1"; then
 			AC_MSG_RESULT([*** libmd crypto library supports MD5])
@@ -336,8 +336,8 @@ AC_CHECK_HEADER(openssl/evp.h, [
 	AC_MSG_RESULT([openssl/evp.h header file found])
 	AC_CHECK_LIB(crypto, EVP_DigestInit_ex,
 	[
-		LDFLAGS_ORIG="$LDFLAGS"
-		LDFLAGS="-lcrypto $LDFLAGS"
+		LIBS_ORIG="$LIBS"
+		LIBS="-lcrypto $LIBS"
 		HAVE_OPENSSL_EVP_MD5=1
 		HAVE_OPENSSL_EVP_MD5_LEGACY=1
 
@@ -357,7 +357,7 @@ AC_CHECK_HEADER(openssl/evp.h, [
 			HAVE_OPENSSL_EVP_MD5_LEGACY=0
 		])
 
-		LDFLAGS="$LDFLAGS_ORIG"
+		LIBS="$LIBS_ORIG"
 
 		if test "$HAVE_OPENSSL_EVP_MD5" = "1"; then
 			AC_MSG_RESULT([*** OpenSSL crypto library supports MD5 via EVP implementation])
@@ -374,8 +374,8 @@ AC_CHECK_HEADER(openssl/md5.h, [
 	AC_MSG_RESULT([openssl/md5.h header file found])
 	AC_CHECK_LIB(crypto, MD5_Init,
 	[
-		LDFLAGS_ORIG="$LDFLAGS"
-		LDFLAGS="-lcrypto $LDFLAGS"
+		LIBS_ORIG="$LIBS"
+		LIBS="-lcrypto $LIBS"
 		HAVE_OPENSSL_MD5=1
 		AC_CHECK_FUNCS(MD5_Init MD5_Update MD5_Final,
 		[
@@ -383,7 +383,7 @@ AC_CHECK_HEADER(openssl/md5.h, [
 			AC_MSG_RESULT([OpenSSL crypto library supports MD5 via legacy implementation])
 			HAVE_OPENSSL_MD5=0
 		])
-		LDFLAGS="$LDFLAGS_ORIG"
+		LIBS="$LIBS_ORIG"
 
 		if test "$HAVE_OPENSSL_MD5" = "1"; then
 			AC_MSG_RESULT([*** OpenSSL crypto library supports MD5 via legacy implementation])