Could not reproduce the issue, that likely is specific to user environment.

Problem should happen when in "find" option menu you write something and drag & drop and press space bar AT THE SAME TIME when you start to drag.

 4702              gtk_entry_get_pixel_ranges (entry, &ranges, &n_ranges);
4703    
4704              button = gtk_gesture_single_get_current_button (GTK_GESTURE_SINGLE (gesture));
4705              gtk_drag_begin_with_coordinates (widget, target_list, actions,
4706                                               button, (GdkEvent*) event,
4707                                               priv->drag_start_x + ranges[0],
4708                                               priv->drag_start_y);
4709              g_free (ranges);

(gdb) p n_ranges
$1 = 0

  Since n_ranges is 0, it is perfectly valid for ranges to be NULL.

  A pseudo patch would be:

4707                                               priv->drag_start_x + (n_ranges ? ranges[0] : 0),