fix behavior of DiskReader when moved after an instrument

2 files changed, 32 insertions, 1 deletions

diff --git a/libs/ardour/ardour/disk_reader.h b/libs/ardour/ardour/disk_reader.h
index 725fa4b2ce..3116435606 100644
--- a/libs/ardour/ardour/disk_reader.h
+++ b/libs/ardour/ardour/disk_reader.h
@@ -50,6 +50,8 @@ public:
 	static samplecnt_t default_chunk_samples ();
 	static void set_chunk_samples (samplecnt_t n) { _chunk_samples = n; }
 
+	bool can_support_io_configuration (const ChanCount& in, ChanCount& out);
+
 	void run (BufferSet& /*bufs*/, samplepos_t /*start_sample*/, samplepos_t /*end_sample*/, double speed, pframes_t /*nframes*/, bool /*result_required*/);
 	void realtime_handle_transport_stopped ();
 	void realtime_locate (bool);
diff --git a/libs/ardour/disk_reader.cc b/libs/ardour/disk_reader.cc
index ea363061d6..fa8a063407 100644
--- a/libs/ardour/disk_reader.cc
+++ b/libs/ardour/disk_reader.cc
@@ -536,7 +536,7 @@ DiskReader::overwrite_existing_audio ()
 {
 	boost::shared_ptr<ChannelList> c = channels.reader();
 
-	if (c->empty ()) {
+	if (c->empty () || !_playlists[DataType::AUDIO]) {
 		return true;
 	}
 
@@ -1683,3 +1683,32 @@ DiskReader::reload_loop ()
 
 	}
 }
+
+bool
+DiskReader::can_support_io_configuration (const ChanCount& in, ChanCount& out)
+{
+	if (!DiskIOProcessor::can_support_io_configuration (in, out)) {
+		return false;
+	}
+
+	/* DiskIO might have done this too, but do it again anyway as a
+	 * starting point.
+	 */
+
+	out == in;
+
+	if (_playlists[DataType::AUDIO]) {
+		ChannelList::size_type naudio = max (ChannelList::size_type (1), channels.reader()->size());
+		if (out.n_audio() < naudio) {
+			out.set (DataType::AUDIO, naudio);
+		}
+	}
+
+	if (_playlists[DataType::MIDI]) {
+		if (out.n_midi() != 1) {
+			out.set (DataType::MIDI, 1);
+		}
+	}
+
+	return true;
+}