From de042dcde763427ace79cb33ad2f1fd7770b2d33 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Thu, 27 Nov 2025 01:31:27 +0100
Subject: [PATCH] De-click External Sends

---
 libs/ardour/delivery.cc | 11 ++++++++++-
 libs/ardour/send.cc     |  8 ++++++--
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/libs/ardour/delivery.cc b/libs/ardour/delivery.cc
index f1092cebfd..e3845afb87 100644
--- a/libs/ardour/delivery.cc
+++ b/libs/ardour/delivery.cc
@@ -322,7 +322,11 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 {
 	assert (_output);
 
-	if (!check_active()) {
+	/* Do not use check_active() here, because we need to continue running
+	 * until the gain has gone to zero.
+	 */
+
+	if (!_active && !_pending_active) {
 		_output->silence (nframes);
 		return;
 	}
@@ -347,6 +351,11 @@ Delivery::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample
 	// which cannot do this.
 
 	tgain = target_gain ();
+	const bool converged = fabsf (_current_gain - tgain) < GAIN_COEFF_DELTA;
+
+	if (converged) {
+		_active = _pending_active;
+	}
 
 	if (tgain != _current_gain) {
 		/* target gain has changed */
diff --git a/libs/ardour/send.cc b/libs/ardour/send.cc
index 6e6af79eea..d6714fa509 100644
--- a/libs/ardour/send.cc
+++ b/libs/ardour/send.cc
@@ -151,7 +151,7 @@ Send::deactivate ()
 samplecnt_t
 Send::signal_latency () const
 {
-	if (!_pending_active) {
+	if (!_pending_active && !_active) {
 		 return 0;
 	}
 	if (_delay_out > _delay_in) {
@@ -242,7 +242,11 @@ Send::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_sample, do
 		return;
 	}
 
-	if (!check_active()) {
+	/* Do not use check_active() here, because we need to continue running
+	 * until the gain has gone to zero.
+	 */
+
+	if (!_active && !_pending_active) {
 		_meter->reset ();
 		_output->silence (nframes);
 		return;