m4/nut_check_libsystemd.m4: check if nut_have_libsystemd_inhibitor [n…

…etworkupstools#1070]

Signed-off-by: Jim Klimov <[email protected]>

configure.ac

@@ -4073,6 +4073,9 @@ AS_IF([test x"${with_libsystemd}" = xyes && test x"${SYSTEMD_SUPPORTS_DAEMON_TYP
 NUT_REPORT_FEATURE([build with tighter systemd support], [${with_libsystemd}], [],
 	[WITH_LIBSYSTEMD], [Define to build with tighter systemd support (sd_notify etc)])
 
+nut_with_libsystemd_inhibitor=0
+AS_IF([test x"${with_libsystemd}" = xyes && test x"${nut_have_libsystemd_inhibitor}" = xyes], [nut_with_libsystemd_inhibitor=1])
+AC_DEFINE_UNQUOTED(WITH_LIBSYSTEMD_INHIBITOR, [${nut_with_libsystemd_inhibitor}], [Define as 1 if we can use systemd inhibitor interface here])
 
 dnl
 dnl Tests for CppUnit availability and usability (will be built if we can,

m4/nut_check_libsystemd.m4

@@ -101,7 +101,12 @@ if test -z "${nut_have_libsystemd_seen}"; then
 		AC_CHECK_FUNCS(sd_booted sd_watchdog_enabled sd_notify_barrier)
 		LIBSYSTEMD_CFLAGS="${CFLAGS}"
 		LIBSYSTEMD_LIBS="${LIBS}"
-	])
+
+		dnl Since systemd 183: https://systemd.io/INHIBITOR_LOCKS/
+		dnl TODO: Which header?
+		nut_have_libsystemd_inhibitor=yes
+		AC_CHECK_FUNCS(Inhibit PrepareForSleep, [], [nut_have_libsystemd_inhibitor=no])
+	], [nut_have_libsystemd_inhibitor=no])
 
 	dnl restore original CFLAGS and LIBS
 	CFLAGS="${CFLAGS_ORIG}"