Part 2, modify lilv API as needed

source/backend/plugin/Lv2Plugin.cpp

@@ -1010,6 +1010,7 @@ public:
     {
         CARLA_ASSERT(fRdfDescriptor != nullptr);
         CARLA_ASSERT(index >= -1 && index < static_cast<int32_t>(fRdfDescriptor->PresetCount));
+        CARLA_ASSERT(sendGui || sendOsc || sendCallback); // never call this from RT
 
         if (index < -1)
             index = -1;
@@ -1018,10 +1019,15 @@ public:
 
         if (index >= 0 && index < static_cast<int32_t>(fRdfDescriptor->PresetCount))
         {
-            const ScopedSingleProcessLocker spl(this, (sendGui || sendOsc || sendCallback));
+            const ScopedDisabler sd(this);
 
             if (const LilvState* state = gLv2World.getState(fRdfDescriptor->Presets[index].URI, (LV2_URID_Map*)fFeatures[kFeatureIdUridMap]->data))
-                lilv_state_restore(state, nullptr, carla_lilv_set_port_value, this, 0, fFeatures);
+            {
+                lilv_state_restore(state, fExt.state, fHandle, carla_lilv_set_port_value, this, 0, fFeatures);
+
+                if (fHandle2 != nullptr)
+                    lilv_state_restore(state, fExt.state, fHandle2, carla_lilv_set_port_value, this, 0, fFeatures);
+            }
         }
 
         CarlaPlugin::setProgram(index, sendGui, sendOsc, sendCallback);

source/libs/lilv/lilv-0.16.0/lilv/lilv.h

@@ -27,6 +27,7 @@
 #include <stdio.h>
 
 #include "lv2/lv2.h"
+#include "lv2/state.h"
 #include "lv2/urid.h"
 
 #ifdef LILV_SHARED
@@ -1415,7 +1416,8 @@ typedef void (*LilvSetPortValueFunc)(const char* port_symbol,
 LILV_API
 void
 lilv_state_restore(const LilvState*           state,
-                   LilvInstance*              instance,
+                   const LV2_State_Interface* iface,
+                   LV2_Handle                 handle,
                    LilvSetPortValueFunc       set_value,
                    void*                      user_data,
                    uint32_t                   flags,

source/libs/lilv/lilv-0.16.0/src/state.c

@@ -399,30 +399,18 @@ lilv_state_new_from_instance(const LilvPlugin*          plugin,
 LILV_API
 void
 lilv_state_restore(const LilvState*           state,
-                   LilvInstance*              instance,
+                   const LV2_State_Interface* iface,
+                   LV2_Handle                 handle,
                    LilvSetPortValueFunc       set_value,
                    void*                      user_data,
                    uint32_t                   flags,
                    const LV2_Feature *const * features)
 {
-	LV2_State_Map_Path map_path = {
-		(LilvState*)state, abstract_path, absolute_path };
-	LV2_Feature map_feature = { LV2_STATE__mapPath, &map_path };
-
-	const LV2_Feature** sfeatures = add_features(features, &map_feature, NULL);
-
-	const LV2_Descriptor*      desc  = instance->lv2_descriptor;
-	const LV2_State_Interface* iface = (desc->extension_data)
-		? (LV2_State_Interface*)desc->extension_data(LV2_STATE__interface)
-		: NULL;
-
 	if (iface) {
-		iface->restore(instance->lv2_handle, retrieve_callback,
-		               (LV2_State_Handle)state, flags, sfeatures);
+		iface->restore(handle, retrieve_callback,
+		               (LV2_State_Handle)state, flags, features);
 	}
 
-	free(sfeatures);
-
 	if (set_value) {
 		for (uint32_t i = 0; i < state->num_values; ++i) {
 			const PortValue* val = &state->values[i];