From 6d83e47860f3dd419d7bb70eae5bc65648636e6a Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 24 Jun 2020 23:56:42 +0200
Subject: [PATCH] Fix Plugin-preset saving when preset exists

Previously the GUI explicitly called remove_preset() before
saving a plugin-preset. This functionality is now moved
into the backend.

This fixes a case when a user tries to save/replace factory presets
and works around https://github.com/lv2/lilv/issues/37
---
 libs/ardour/audio_unit.cc    |  3 +++
 libs/ardour/ladspa_plugin.cc |  2 ++
 libs/ardour/lv2_plugin.cc    | 10 ++++++++++
 libs/ardour/plugin.cc        | 25 ++++++++++++++++++-------
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/libs/ardour/audio_unit.cc b/libs/ardour/audio_unit.cc
index d3b88d66c9..699e7090c4 100644
--- a/libs/ardour/audio_unit.cc
+++ b/libs/ardour/audio_unit.cc
@@ -2224,6 +2224,9 @@ AUPlugin::do_save_preset (string preset_name)
 
 	user_preset_path = Glib::build_filename (v);
 
+	/* delete old preset if it exists */
+	g_unlink (user_preset_path.c_str());
+
 	set_preset_name_in_plist (propertyList, preset_name);
 
 	if (save_property_list (propertyList, user_preset_path)) {
diff --git a/libs/ardour/ladspa_plugin.cc b/libs/ardour/ladspa_plugin.cc
index e1f43b54a1..f9ac3eb63f 100644
--- a/libs/ardour/ladspa_plugin.cc
+++ b/libs/ardour/ladspa_plugin.cc
@@ -899,6 +899,8 @@ string
 LadspaPlugin::do_save_preset (string name)
 {
 #ifdef HAVE_LRDF
+	do_remove_preset (name);
+
 	/* make a vector of pids that are input parameters */
 	vector<int> input_parameter_pids;
 	for (uint32_t i = 0; i < parameter_count(); ++i) {
diff --git a/libs/ardour/lv2_plugin.cc b/libs/ardour/lv2_plugin.cc
index a69ea0f819..24e08ac1c6 100644
--- a/libs/ardour/lv2_plugin.cc
+++ b/libs/ardour/lv2_plugin.cc
@@ -1633,6 +1633,15 @@ LV2Plugin::do_save_preset(string name)
 #endif
 
 	/* delete reference to old preset (if any) */
+#if 0 // prefer this when https://github.com/lv2/lilv/issues/37 is resolved
+	do_remove_preset (name);
+#else
+	/* this works around https://github.com/lv2/lilv/issues/37
+	 *
+	 * do_remove_preset() calls lilv_state_delete(); That
+	 * deletes all mapped files without re-creating them.
+	 * So for the time being we just leave them in place.
+	 */
 	const PresetRecord* r = preset_by_label(name);
 	if (r) {
 		LilvNode*  pset  = lilv_new_uri (_world.world, r->uri.c_str());
@@ -1641,6 +1650,7 @@ LV2Plugin::do_save_preset(string name)
 			lilv_node_free(pset);
 		}
 	}
+#endif
 
 	LilvState* state = lilv_state_new_from_instance(
 		_impl->plugin,
diff --git a/libs/ardour/plugin.cc b/libs/ardour/plugin.cc
index 1330011173..748019e450 100644
--- a/libs/ardour/plugin.cc
+++ b/libs/ardour/plugin.cc
@@ -153,20 +153,31 @@ Plugin::remove_preset (string name)
 Plugin::PresetRecord
 Plugin::save_preset (string name)
 {
-	if (preset_by_label (name)) {
-		PBD::error << _("Preset with given name already exists.") << endmsg;
+	Plugin::PresetRecord const* p = preset_by_label (name);
+	if (p && !p->user) {
+		PBD::error << _("A factory presets with given name already exists.") << endmsg;
 		return Plugin::PresetRecord ();
 	}
 
 	string const uri = do_save_preset (name);
 
-	if (!uri.empty()) {
-		_presets.insert (make_pair (uri, PresetRecord (uri, name)));
-		_have_presets = false;
-		PresetsChanged (unique_id(), this, true); /* EMIT SIGNAL */
-		PresetAdded (); /* EMIT SIGNAL */
+	if (uri.empty()) {
+		/* save failed, clean up preset */
+		do_remove_preset (name);
+		PBD::error << _("Failed to save plugin preset.") << endmsg;
+		return Plugin::PresetRecord ();
 	}
 
+	if (p) {
+		_presets.erase (p->uri);
+		_parameter_changed_since_last_preset = false;
+	}
+
+	_presets.insert (make_pair (uri, PresetRecord (uri, name)));
+	_have_presets = false;
+	PresetsChanged (unique_id(), this, true); /* EMIT SIGNAL */
+	PresetAdded (); /* EMIT SIGNAL */
+
 	return PresetRecord (uri, name);
 }