From 01286b442ee2e09472aebe8491b2755c82f07e44 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 26 Apr 2016 12:56:52 +0200
Subject: [PATCH] don't show engine dialog when loading a session..

..and the engine is running at the desired samplerate
---
 libs/ardour/ardour/session.h |  2 +-
 libs/ardour/session.cc       | 11 ++++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 5734ec4c87..f81ff3efcd 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1414,7 +1414,7 @@ class LIBARDOUR_API Session : public PBD::StatefulDestructible, public PBD::Scop
 	void             auto_loop_changed (Location *);
 	void             auto_loop_declick_range (Location *, framepos_t &, framepos_t &);
 
-	int  ensure_engine (uint32_t desired_sample_rate);
+	int  ensure_engine (uint32_t desired_sample_rate, bool);
 	void pre_engine_init (std::string path);
 	int  post_engine_init ();
 	int  immediately_post_engine ();
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 38324075c4..6555d27f81 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -333,7 +333,7 @@ Session::Session (AudioEngine &eng,
 #ifdef USE_TRACKS_CODE_FEATURES
 		sr = EngineStateController::instance()->get_current_sample_rate();
 #endif
-		if (ensure_engine (sr)) {
+		if (ensure_engine (sr, true)) {
 			destroy ();
 			throw SessionException (_("Cannot connect to audio/midi engine"));
 		}
@@ -387,7 +387,7 @@ Session::Session (AudioEngine &eng,
 			}
 		}
 
-		if (ensure_engine (sr)) {
+		if (ensure_engine (sr, false)) {
 			destroy ();
 			throw SessionException (_("Cannot connect to audio/midi engine"));
 		}
@@ -500,7 +500,7 @@ Session::init_name_id_counter (guint n)
 }
 
 int
-Session::ensure_engine (uint32_t desired_sample_rate)
+Session::ensure_engine (uint32_t desired_sample_rate, bool isnew)
 {
 	if (_engine.current_backend() == 0) {
 		/* backend is unknown ... */
@@ -508,6 +508,8 @@ Session::ensure_engine (uint32_t desired_sample_rate)
 		if (r.get_value_or (-1) != 0) {
 			return -1;
 		}
+	} else if (!isnew && _engine.running() && _engine.sample_rate () == desired_sample_rate) {
+		/* keep engine */
 	} else if (_engine.setup_required()) {
 		/* backend is known, but setup is needed */
 		boost::optional<int> r = AudioEngineSetupRequired (desired_sample_rate);
@@ -520,8 +522,7 @@ Session::ensure_engine (uint32_t desired_sample_rate)
 		}
 	}
 
-	/* at this point the engine should be running
-	*/
+	/* at this point the engine should be running */
 
 	if (!_engine.running()) {
 		return -1;