From 7408a9958e6e7d46f97a7787bb1aef5a5dc8560c Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Sat, 6 Aug 2022 21:44:55 +0200
Subject: [PATCH] Fix duplicate UI initialization

When loading the very first session is canceled (e.g.
sample-rate mismatch -> Do not load session) or fails otherwise,
execution returns to the startupFSM.

Loading another session after that then takes the same path again:

StartupFSM::dialog_response_handler() -> StartupFSM::engine_running()
-> ARDOUR_UI::attach_to_engine()

The call needs to be idempotent, otherwise setup_windows(),
create_editor() etc are called a second time and Ardour crashes.
---
 gtk2_ardour/ardour_ui.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gtk2_ardour/ardour_ui.cc b/gtk2_ardour/ardour_ui.cc
index 9dac19ca19..884685d605 100644
--- a/gtk2_ardour/ardour_ui.cc
+++ b/gtk2_ardour/ardour_ui.cc
@@ -593,8 +593,13 @@ ARDOUR_UI::create_global_port_matrix (ARDOUR::DataType type)
 void
 ARDOUR_UI::attach_to_engine ()
 {
+	static bool first_time = true;
+	if (!first_time) {
+		return;
+	}
 	AudioEngine::instance()->Running.connect (forever_connections, MISSING_INVALIDATOR, boost::bind (&ARDOUR_UI::engine_running, this, _1), gui_context());
 	engine_running (0);
+	first_time = false;
 }
 
 void