configure.ac: detect jack_set_info_function()

configure.ac

@@ -620,6 +620,16 @@ if test x$enable_jack = xyes; then
 	                  [enable_jack=no;AC_MSG_WARN([JACK not found -- disabling])])
 fi
 
+if test x$enable_jack = xyes; then
+	# check whether jack_set_info_function() is available
+	old_LIBS=$LIBS
+	LIBS="$LIBS $JACK_LIBS"
+
+	AC_CHECK_FUNCS(jack_set_info_function)
+
+	LIBS=$old_LIBS
+fi
+
 AM_CONDITIONAL(HAVE_JACK, test x$enable_jack = xyes)
 
 if test x$enable_id3 = xyes; then

src/output/jack_plugin.c

@@ -165,11 +165,13 @@ mpd_jack_error(const char *msg)
 	g_warning("%s", msg);
 }
 
+#ifdef HAVE_JACK_SET_INFO_FUNCTION
 static void
 mpd_jack_info(const char *msg)
 {
 	g_message("%s", msg);
 }
+#endif
 
 static void *
 mpd_jack_init(struct audio_output *ao,
@@ -205,7 +207,10 @@ mpd_jack_init(struct audio_output *ao,
 		config_get_block_unsigned(param, "ringbuffer_size", 32768);
 
 	jack_set_error_function(mpd_jack_error);
+
+#ifdef HAVE_JACK_SET_INFO_FUNCTION
 	jack_set_info_function(mpd_jack_info);
+#endif
 
 	return jd;
 }