Bug2588: Amend the fix at 3c76cea to be safe during append-record

src/tracks/playabletrack/wavetrack/ui/SpectrumView.cpp

@@ -637,6 +637,15 @@ void SpectrumView::Draw(
 {
    if ( iPass == TrackArtist::PassTracks ) {
       auto &dc = context.dc;
+      // Update cache for locations, e.g. cutlines and merge points
+      // Bug2588: do this for both channels, even if one is not drawn, so that
+      // cut-line editing (which depends on the locations cache) works properly.
+      // If both channels are visible, we will duplicate this effort, but that
+      // matters little.
+      for( auto channel:
+          TrackList::Channels(static_cast<WaveTrack*>(FindTrack().get())) )
+         channel->UpdateLocationsCache();
+
       const auto wt = std::static_pointer_cast<const WaveTrack>(
          FindTrack()->SubstitutePendingChangedTrack());
 

src/tracks/playabletrack/wavetrack/ui/WaveTrackView.cpp

@@ -728,14 +728,6 @@ void WaveTrackSubView::DrawBoldBoundaries(
    auto &dc = context.dc;
    const auto artist = TrackArtist::Get( context );
 
-   // Update cache for locations, e.g. cutlines and merge points
-   // Bug2588: do this for both channels, even if one is not drawn, so that
-   // cut-line editing (which depends on the locations cache) works properly.
-   // If both channels are visible, we will duplicate this effort, but that
-   // matters little.
-   for( auto channel: TrackList::Channels(track))
-      channel->UpdateLocationsCache();
-
    const auto &zoomInfo = *artist->pZoomInfo;
 
 #ifdef EXPERIMENTAL_TRACK_PANEL_HIGHLIGHTING

src/tracks/playabletrack/wavetrack/ui/WaveformView.cpp

@@ -1008,6 +1008,15 @@ void WaveformView::Draw(
 {
    if ( iPass == TrackArtist::PassTracks ) {
       auto &dc = context.dc;
+      // Update cache for locations, e.g. cutlines and merge points
+      // Bug2588: do this for both channels, even if one is not drawn, so that
+      // cut-line editing (which depends on the locations cache) works properly.
+      // If both channels are visible, we will duplicate this effort, but that
+      // matters little.
+      for( auto channel:
+          TrackList::Channels(static_cast<WaveTrack*>(FindTrack().get())) )
+         channel->UpdateLocationsCache();
+
       const auto wt = std::static_pointer_cast<const WaveTrack>(
          FindTrack()->SubstitutePendingChangedTrack());