build-sys: workaround for autoconf "present but cannot be compiled"

See also:
https://www.gnu.org/software/autoconf/manual/autoconf-2.64/html_node/Present-But-Cannot-Be-Compiled.html

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/configure.ac b/configure.ac
index 30940ba2b99533f88cf91e8b2a5b4aa742a391de..2dbf592a009ca7170e88870da79b14bb7525fb61 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -216,7 +216,6 @@ AC_CHECK_HEADERS([ \
        linux/fd.h \
        linux/raw.h \
        linux/tiocl.h \
-       linux/gsmmux.h \
        linux/version.h \
        linux/securebits.h \
        locale.h \
@@ -262,6 +261,12 @@ AC_CHECK_HEADERS([ \
        utmp.h \
 ])
 
+AC_CHECK_HEADERS([linux/gsmmux.h ], [], [],
+ [#ifdef LINUX_GSMMUX_H
+   # include <linux/gsmmux.h>
+   #endif
+])
+
 AC_CHECK_HEADERS([security/pam_misc.h],
                [AM_CONDITIONAL([HAVE_LINUXPAM], [true])],
                [AM_CONDITIONAL([HAVE_LINUXPAM], [false])], [