From 1c0651f7f4974fb404cf89f2233df01192ec1b24 Mon Sep 17 00:00:00 2001
From: nick_m <mainsbridge@gmail.com>
Date: Sat, 13 Aug 2016 05:37:18 +1000
Subject: [PATCH] Ensure BBTRulerDrag operates within the tempo map.

---
 gtk2_ardour/editor_drag.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gtk2_ardour/editor_drag.cc b/gtk2_ardour/editor_drag.cc
index 5852f10b43..20e8b4f054 100644
--- a/gtk2_ardour/editor_drag.cc
+++ b/gtk2_ardour/editor_drag.cc
@@ -3430,7 +3430,7 @@ void
 BBTRulerDrag::setup_pointer_frame_offset ()
 {
 	TempoMap& map (_editor->session()->tempo_map());
-	const double beat_at_frame = map.beat_at_frame (raw_grab_frame());
+	const double beat_at_frame = max (0.0, map.beat_at_frame (raw_grab_frame()));
 	const uint32_t divisions = _editor->get_grid_beat_divisions (0);
 	double beat = 0.0;