From 720664d9d37bc272014d7d435468d01180eb666b Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 18 Feb 2020 20:44:49 +0100
Subject: [PATCH] Fix loading send gain automation

This cleans up various issues that have been accumulated over the past
and fixes bugs introduced in d4e023e1 and e31f5d99.

Previously GainControl as saved as part of the Amp, however the
automation was saved via Send (is-a Automatable).

In d4e023e1cb, the GainControl was changed a "BusSendLevel"
parameter, but AutomationList was not updated. This prevented
loading existing automation (control parameter was not found).
---
 libs/ardour/send.cc | 54 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 10 deletions(-)

diff --git a/libs/ardour/send.cc b/libs/ardour/send.cc
index d913693909..d3a5a3b28e 100644
--- a/libs/ardour/send.cc
+++ b/libs/ardour/send.cc
@@ -30,6 +30,7 @@
 #include "ardour/buffer_set.h"
 #include "ardour/debug.h"
 #include "ardour/delayline.h"
+#include "ardour/event_type_map.h"
 #include "ardour/gain_control.h"
 #include "ardour/io.h"
 #include "ardour/meter.h"
@@ -100,7 +101,7 @@ Send::Send (Session& s, boost::shared_ptr<Pannable> p, boost::shared_ptr<MuteMas
 
 	//boost_debug_shared_ptr_mark_interesting (this, "send");
 
-	boost::shared_ptr<AutomationList> gl (new AutomationList (Evoral::Parameter (GainAutomation)));
+	boost::shared_ptr<AutomationList> gl (new AutomationList (Evoral::Parameter (BusSendLevel)));
 	_gain_control = boost::shared_ptr<GainControl> (new GainControl (_session, Evoral::Parameter(BusSendLevel), gl));
 	_gain_control->set_flags (Controllable::Flag ((int)_gain_control->flags() | Controllable::InlineControl));
 	add_control (_gain_control);
@@ -279,7 +280,7 @@ Send::state ()
 
 	node.set_property ("selfdestruct", _remove_on_disconnect);
 
-	node.add_child_nocopy (_amp->get_state ());
+	node.add_child_nocopy (_gain_control->get_state());
 
 	return node;
 }
@@ -291,11 +292,51 @@ Send::set_state (const XMLNode& node, int version)
 		return set_state_2X (node, version);
 	}
 
-	XMLProperty const * prop;
+	XMLNode* gain_node;
+	if ((gain_node = node.child (Controllable::xml_node_name.c_str ())) != 0) {
+		_gain_control->set_state (*gain_node, version);
+	}
+
+	if (version <= 6000) {
+		/* convert GainAutomation to BusSendLevel
+		 *
+		 * (early Ardour 6.0-pre0 and Mixbus 6.0 used "BusSendLevel"
+		 *  control with GainAutomation, so we check version <= 6000.
+		 *  New A6 sessions do not have a GainAutomation parameter,
+		 *  so this is safe.)
+		 *
+		 * Normally this is restored via
+		 * Delivery::set_state() -> Processor::set_state()
+		 * -> Automatable::set_automation_xml_state()
+		 */
+		XMLNodeList nlist;
+		XMLNode* automation = node.child ("Automation");
+		if (automation) {
+			nlist = automation->children();
+		}
+		for (XMLNodeIterator i = nlist.begin(); i != nlist.end(); ++i) {
+			if ((*i)->name() != "AutomationList") {
+				continue;
+			}
+			XMLProperty const* id_prop = (*i)->property("automation-id");
+			if (!id_prop) {
+				continue;
+			}
+			Evoral::Parameter param = EventTypeMap::instance().from_symbol (id_prop->value());
+			if (param.type() != GainAutomation) {
+				continue;
+			}
+			XMLNode xn (**i);
+			xn.set_property ("automation-id", EventTypeMap::instance().to_symbol(Evoral::Parameter (BusSendLevel)));
+			_gain_control->alist()->set_state (xn, version);
+			break;
+		}
+	}
 
 	Delivery::set_state (node, version);
 
 	if (node.property ("ignore-bitslot") == 0) {
+		XMLProperty const* prop;
 
 		/* don't try to reset bitslot if there is a node for it already: this can cause
 		   issues with the session's accounting of send ID's
@@ -328,13 +369,6 @@ Send::set_state (const XMLNode& node, int version)
 
 	node.get_property (X_("selfdestruct"), _remove_on_disconnect);
 
-	XMLNodeList nlist = node.children();
-	for (XMLNodeIterator i = nlist.begin(); i != nlist.end(); ++i) {
-		if ((*i)->name() == X_("Processor")) {
-			_amp->set_state (**i, version);
-		}
-	}
-
 	_send_delay->set_name ("Send-" + name());
 	_thru_delay->set_name ("Thru-" + name());