From aef363c7e8e942224e6cffc4398366c6e5d31749 Mon Sep 17 00:00:00 2001
From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Date: Thu, 11 Jun 2020 00:04:32 +0200
Subject: [PATCH] configure.ac: fix build failure when crypt() does not require
 libcrypt

Since commit 522246d20e4cd92fadc2d760228cb7e78cbeb4c5, the build fails
if "none required" is returned by AC_SEARCH_LIBS for libcrypt.

Resolves: https://github.com/linux-pam/linux-pam/pull/235
Fixes: http://autobuild.buildroot.org/results/92b3dd7c984d2b843ac9aacacd69eec99f28743e
Fixes: v1.4.0~228 ("Use cached 'crypt' library result correctly")

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
---
 configure.ac | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index ea08a7a3..c1862ea7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -428,7 +428,11 @@ AS_IF([test "x$ac_cv_header_xcrypt_h" = "xyes"],
   [crypt_libs="crypt"])
 
 BACKUP_LIBS=$LIBS
-AC_SEARCH_LIBS([crypt],[$crypt_libs], LIBCRYPT="${ac_cv_search_crypt}", LIBCRYPT="")
+AC_SEARCH_LIBS([crypt],[$crypt_libs])
+case "$ac_cv_search_crypt" in
+	-l*) LIBCRYPT="$ac_cv_search_crypt" ;;
+	*) LIBCRYPT="" ;;
+esac
 AC_CHECK_FUNCS(crypt_r crypt_gensalt_r)
 LIBS=$BACKUP_LIBS
 AC_SUBST(LIBCRYPT)