commit 22352b90e78e2d162b98b5ef6c84672c397be40a
Author: Lars Wendler <polynomial-c@gentoo.org>
Date:   Wed Mar 17 17:49:18 2021 +0100

    autoconf-2.70 fix
    
    autoconf-2.70 and newer are more strict with quoting etc. and thus generate
    a broken configure file:
    
      configure: 20855: Syntax error: ")" unexpected (expecting "fi")
    
    Gentoo-bug: https://bugs.gentoo.org/776241
    Signed-off-by: Lars Wendler <polynomial-c@gentoo.org>

diff --git a/cf/check-var.m4 b/cf/check-var.m4
index 2fd7bca6f..71d6f70ca 100644
--- a/cf/check-var.m4
+++ b/cf/check-var.m4
@@ -20,7 +20,7 @@ AC_MSG_RESULT($ac_foo)
 if test "$ac_foo" = yes; then
 	AC_DEFINE_UNQUOTED(AS_TR_CPP(HAVE_[]$1), 1, 
 		[Define if you have the `]$1[' variable.])
-	m4_ifval([$2], AC_CHECK_DECLS([$1],[],[],[$2]))
+	m4_ifval([$2], [AC_CHECK_DECLS([$1],[],[],[$2])])
 fi
 ])