From ffe7fcd3b0a49158ef1160e38162f7e413c8c1f4 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Wed, 29 Jan 2020 05:35:36 +0100
Subject: [PATCH] Allow to dis/engage rec-arm while looping

---
 libs/ardour/disk_writer.cc | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/libs/ardour/disk_writer.cc b/libs/ardour/disk_writer.cc
index cddfe7b09b..aafdcc5dcd 100644
--- a/libs/ardour/disk_writer.cc
+++ b/libs/ardour/disk_writer.cc
@@ -463,6 +463,17 @@ DiskWriter::run (BufferSet& bufs, samplepos_t start_sample, samplepos_t end_samp
 				*/
 				_capture_captured     = start_sample - loop_start;
 				_capture_start_sample = loop_start;
+				if (_capture_captured > 0) {
+					/* when enabling record while already looping,
+					 * zero fill region back to loop-start.
+					 */
+					for (chan = c->begin(), n = 0; chan != c->end(); ++chan, ++n) {
+						ChannelInfo* chaninfo (*chan);
+						for (samplecnt_t s = 0; s < _capture_captured; ++s) {
+							chaninfo->wbuf->write_one (0); // TODO: optimize
+						}
+					}
+				}
 			}
 
 			if (_midi_write_source) {