Fix move existing track when adding duplicate with note

Fixes #161

app/models.py

@@ -373,6 +373,15 @@ class PlaylistRows(Base):
         session.add(self)
         session.flush()
 
+    def append_note(self, extra_note: str) -> None:
+        """Append passed note to any existing note"""
+
+        current_note = self.note
+        if current_note:
+            self.note = current_note + '\n' + extra_note
+        else:
+            self.note = extra_note
+
     @staticmethod
     def copy_playlist(session: scoped_session,
                       src_id: int,

app/playlists.py

@@ -696,7 +696,11 @@ class PlaylistTab(QTableWidget):
         if existing_plr and ask_yes_no("Duplicate row",
                                        "Track already in playlist. "
                                        "Move to new location?"):
-            # Yes it is and we shoudl reuse it
+            # Yes it is and we should reuse it
+            # If we've been passed a note, we need to add that to the
+            # existing track
+            if note:
+                existing_plr.append_note(note)
             return self._move_row(session, existing_plr, row_number)
 
         # Build playlist_row object
@@ -1356,7 +1360,8 @@ class PlaylistTab(QTableWidget):
 
         return playlistrow_id
 
-    def _get_playlistrow_object(self, session: scoped_session, row: int) -> int:
+    def _get_playlistrow_object(self, session: scoped_session,
+                                row: int) -> int:
         """Return the playlistrow object associated with this row"""
 
         playlistrow_id = (self.item(row, USERDATA).data(self.PLAYLISTROW_ID))