+
+ if (!rec_regions.empty()) {
+ MidiRegionView* mrv = dynamic_cast<MidiRegionView*> (rec_regions.back().second);
+ mrv->end_write ();
+ }
+
+ PropertyList plist;
+
+ plist.add (ARDOUR::Properties::start, start);
+ plist.add (ARDOUR::Properties::length, 1);
+ /* Just above we're setting this nascent region's length to 1. I think this
+ is so that the RegionView gets created with a non-zero width, as apparently
+ creating a RegionView with a zero width causes it never to be displayed
+ (there is a warning in TimeAxisViewItem::init about this). However, we
+ must also set length_beats to something non-zero, otherwise the frame length
+ of 1 causes length_beats to be set to some small quantity << 1. Then
+ when the position is set up below, this length_beats is used to recompute
+ length using BeatsFramesConverter::to, which is slightly innacurate for small
+ beats values because it converts floating point beats to bars, beats and
+ integer ticks. The upshot of which being that length gets set back to 0,
+ meaning no region view is ever seen, meaning no MIDI notes during record (#3820).
+ */
+ plist.add (ARDOUR::Properties::length_beats, 1);
+ plist.add (ARDOUR::Properties::name, string());
+ plist.add (ARDOUR::Properties::layer, 0);
+