From 2bb259f6cbef1686175a469a6007b0f2d0d69415 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Sat, 3 Jan 2026 09:55:31 -0700
Subject: [PATCH] prevent drags on the tempo/meter markers representing a BBT
 marker

---
 gtk2_ardour/editor_drag.cc  | 11 +++++++++++
 gtk2_ardour/editor_mouse.cc | 11 ++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index 2a3e1af3d0..5e3b903f09 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -3078,6 +3078,12 @@ MeterMarkerDrag::MeterMarkerDrag (Editor& e, ArdourCanvas::Item* i, bool c)
 	, _old_snap_mode (e.snap_mode ())
 	, before_state (0)
 {
+	Temporal::MeterPoint const & mp (_marker->meter());
+
+	if (dynamic_cast<Temporal::MusicTimePoint const *> (&mp)) {
+		throw failed_constructor ();
+	}
+
 	DEBUG_TRACE (DEBUG::Drags, "New MeterMarkerDrag\n");
 	assert (_marker);
 	_movable = !TempoMap::use ()->is_initial (_marker->meter ());
@@ -3280,6 +3286,11 @@ TempoMarkerDrag::TempoMarkerDrag (Editor& e, ArdourCanvas::Item* i)
 
 	_marker       = reinterpret_cast<TempoMarker*> (_item->get_data ("marker"));
 	_real_section = &_marker->tempo ();
+
+	if (dynamic_cast<Temporal::MusicTimePoint const *> (_real_section)) {
+		throw failed_constructor ();
+	}
+
 	_movable      = !TempoMap::use ()->is_initial (_marker->tempo ());
 	_grab_bpm     = _real_section->note_types_per_minute ();
 	_grab_qn      = _real_section->beats ();
diff --git a/gtk2_ardour/editor_mouse.cc b/gtk2_ardour/editor_mouse.cc
index 88c729f6d5..f7d2465b3e 100644
--- a/gtk2_ardour/editor_mouse.cc
+++ b/gtk2_ardour/editor_mouse.cc
@@ -574,7 +574,10 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 		if (ArdourKeyboard::indicates_constraint (event->button.state)) {
 			_drags->set (new TempoEndDrag (*this, item), event);
 		} else {
-			_drags->set (new TempoMarkerDrag (*this, item), event);
+			try {
+				_drags->set (new TempoMarkerDrag (*this, item), event);
+			} catch (...) {
+			}
 		}
 
 		return true;
@@ -588,8 +591,10 @@ Editor::button_press_handler_1 (ArdourCanvas::Item* item, GdkEvent* event, ItemT
 		return true;
 
 	case MeterMarkerItem:
-		_drags->set (
-			new MeterMarkerDrag (*this, item, ArdourKeyboard::indicates_copy (event->button.state)), event);
+		try {
+			_drags->set (new MeterMarkerDrag (*this, item, ArdourKeyboard::indicates_copy (event->button.state)), event);
+		} catch (...) {
+		}
 		return true;
 
 	case VideoBarItem: