Prepare for non-bypassable plugins (Mixbus channelstrip)

libs/ardour/ardour/plugin_insert.h

@@ -115,6 +115,10 @@ public:
 
 #ifdef MIXBUS
 	bool is_channelstrip () const;
+	bool is_nonbypassable () const;
+#else
+	bool is_channelstrip () const { return false; }
+	bool is_nonbypassable () const { return false; }
 #endif
 
 	void set_input_map (uint32_t, ChanMapping);

libs/ardour/luabindings.cc

@@ -1462,6 +1462,8 @@ LuaBindings::common (lua_State* L)
 		.addFunction ("type", &PluginInsert::type)
 		.addFunction ("signal_latency", &PluginInsert::signal_latency)
 		.addFunction ("get_count", &PluginInsert::get_count)
+		.addFunction ("is_channelstrip", &PluginInsert::is_channelstrip)
+		.addFunction ("is_nonbypassable", &PluginInsert::is_channelstrip)
 		.endClass ()
 
 		.deriveWSPtrClass <ReadOnlyControl, PBD::StatefulDestructible> ("ReadOnlyControl")

libs/ardour/plugin_insert.cc

@@ -639,6 +639,11 @@ PluginInsert::activate ()
 void
 PluginInsert::deactivate ()
 {
+#ifdef MIXBUS
+	if (is_nonbypassable ()) {
+		return;
+	}
+#endif
 	_timing_stats.reset ();
 	Processor::deactivate ();
 
@@ -1551,6 +1556,10 @@ bool
 PluginInsert::is_channelstrip () const {
 	return _plugins.front()->is_channelstrip();
 }
+bool
+PluginInsert::is_nonbypassable () const {
+	return _plugins.front()->is_nonbypassable ();
+}
 #endif
 
 bool