From 4a56b92b13591f41c28cbd69c06c78ff2562b3c8 Mon Sep 17 00:00:00 2001
From: nick_m <mainsbridge@gmail.com>
Date: Thu, 5 Jan 2017 00:15:14 +1100
Subject: [PATCH] disallow tempi of 0 ntpm or less.

---
 libs/ardour/tempo.cc | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/libs/ardour/tempo.cc b/libs/ardour/tempo.cc
index 7c281a3e13..7bb542fb51 100644
--- a/libs/ardour/tempo.cc
+++ b/libs/ardour/tempo.cc
@@ -1058,6 +1058,10 @@ TempoMap::do_insert (MetricSection* section)
 TempoSection*
 TempoMap::add_tempo (const Tempo& tempo, const double& pulse, const framepos_t& frame, ARDOUR::TempoSection::Type type, PositionLockStyle pls)
 {
+	if (tempo.note_types_per_minute() <= 0.0) {
+		return 0;
+	}
+
 	TempoSection* ts = 0;
 	{
 		Glib::Threads::RWLock::WriterLock lm (lock);
@@ -1073,6 +1077,10 @@ TempoMap::add_tempo (const Tempo& tempo, const double& pulse, const framepos_t&
 void
 TempoMap::replace_tempo (const TempoSection& ts, const Tempo& tempo, const double& pulse, const framepos_t& frame, TempoSection::Type type, PositionLockStyle pls)
 {
+	if (tempo.note_types_per_minute() <= 0.0) {
+		return;
+	}
+
 	const bool locked_to_meter = ts.locked_to_meter();
 
 	{