From b890cf73ad54adfff08b181694ad1d42b6fe2b7f Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sun, 17 Mar 2019 17:19:02 +0100
Subject: [PATCH] Prepare to configure procs only once - fix missing panners

During session load, all earlier configure_processors() calls
were useless and not taking I/O into account! The Delivery ::pan_out()
needs _output I/O ports in order to correctly report the correct
port-count!

This worked in earlier versions because Config->map_parameters()
triggered [two] processor re-configs via ::listen_position_changed().
That behavior was changed in 1af123465c290664
---
 libs/ardour/session_state.cc | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/libs/ardour/session_state.cc b/libs/ardour/session_state.cc
index b7c4faf5a4..1a25fd4e36 100644
--- a/libs/ardour/session_state.cc
+++ b/libs/ardour/session_state.cc
@@ -316,6 +316,19 @@ Session::post_engine_init ()
 		config.map_parameters (ft);
 		_butler->map_parameters ();
 
+		/* Configure all processors; now that the
+		 * engine is running, ports are re-established,
+		 * and IOChange are complete.
+		 */
+		{
+			Glib::Threads::Mutex::Lock lx (AudioEngine::instance()->process_lock ());
+			ProcessorChangeBlocker pcb (this);
+			boost::shared_ptr<RouteList> r = routes.reader ();
+			for (RouteList::iterator i = r->begin(); i != r->end(); ++i) {
+				(*i)->configure_processors (0);
+			}
+		}
+
 		/* Reset all panners */
 
 		Delivery::reset_panners ();