Make getting current row safer

app/musicmuster.py

@@ -666,6 +666,17 @@ class Window(QMainWindow, Ui_MainWindow):
 
         return idx
 
+    def current_row_or_end(self) -> int:
+        """
+        If a row or rows are selected, return the row number of the first
+        selected row otherwise return the row number for a new row at the
+        of the playlist.
+        """
+
+        if self.current.selected_rows:
+            return self.current.selected_rows[0]
+        return self.current.base_model.rowCount()
+
     def debug(self):
         """Invoke debugger"""
 
@@ -848,7 +859,7 @@ class Window(QMainWindow, Ui_MainWindow):
         # garbage collected while import threads are still running
         self.importer = FileImporter(
             self.current.base_model,
-            self.current.selected_rows[0],
+            self.current_row_or_end()
         )
         self.importer.do_import()
 
@@ -862,27 +873,19 @@ class Window(QMainWindow, Ui_MainWindow):
         dlg.resize(500, 100)
         ok = dlg.exec()
         if ok:
-            if self.current.selected_rows:
-                new_row_number = self.current.selected_rows[0]
-            else:
-                new_row_number = self.current.base_model.rowCount()
             self.current.base_model.insert_row(
-                proposed_row_number=new_row_number,
+                proposed_row_number=self.current_row_or_end(),
                 note=dlg.textValue(),
             )
 
     def insert_track(self) -> None:
         """Show dialog box to select and add track from database"""
 
-        if self.current.selected_rows:
-            new_row_number = self.current.selected_rows[0]
-        else:
-            new_row_number = self.current.base_model.rowCount()
         with db.Session() as session:
             dlg = TrackSelectDialog(
                 parent=self,
                 session=session,
-                new_row_number=new_row_number,
+                new_row_number=self.current_row_or_end(),
                 base_model=self.current.base_model,
             )
             dlg.exec()
@@ -1147,11 +1150,7 @@ class Window(QMainWindow, Ui_MainWindow):
             return
 
         to_playlist_model = self.current.base_model
-        selected_rows = self.current.selected_rows
+        destination_row = self.current_row_or_end()
-        if selected_rows:
-            destination_row = selected_rows[0]
-        else:
-            destination_row = self.current.base_model.rowCount()
 
         # If we move a row to immediately under the current track, make
         # that moved row the next track
@@ -1516,7 +1515,10 @@ class Window(QMainWindow, Ui_MainWindow):
         next track. If no next track, return None.
         """
 
-        row_number = self.current.selected_rows[0]
+        row_number: Optional[int] = None
+
+        if self.current.selected_rows:
+            row_number = self.current.selected_rows[0]
         if row_number is None:
             if track_sequence.next:
                 if track_sequence.next.track_id: