Program: 19011
Project: 19011
Buggy source:
/** 
 * Main handler for PlayerInterfact events.
 * @param event		the event to handle
 * @return			true if the event has been handled and should be cancelled now, false otherwise
 * @throws SMSException	for any error that should be reported to the player
 */
private boolean handleInteraction(PlayerInteractEvent event) throws SMSException {
  Player player=event.getPlayer();
  Block block=event.getClickedBlock();
  SMSMapView mapView=player.getItemInHand().getType() == Material.MAP ? SMSMapView.getViewForId(player.getItemInHand().getDurability()) : null;
  if (block == null && mapView == null) {
    return false;
  }
  ScrollingMenuSign plugin=ScrollingMenuSign.getInstance();
  SMSView locView=block == null ? null : SMSView.getViewForLocation(block.getLocation());
  if (plugin.expecter.isExpecting(player,ExpectCommandSubstitution.class)) {
    plugin.expecter.cancelAction(player,ExpectCommandSubstitution.class);
    MiscUtil.alertMessage(player,"String_Node_Str");
  }
 else   if (plugin.expecter.isExpecting(player,ExpectViewCreation.class) && block != null) {
    if (event.getAction() == Action.LEFT_CLICK_BLOCK) {
      ExpectViewCreation c=(ExpectViewCreation)plugin.expecter.getAction(player,ExpectViewCreation.class);
      c.setLocation(block.getLocation());
      plugin.expecter.handleAction(player,c.getClass());
    }
 else     if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
      plugin.expecter.cancelAction(player,ExpectViewCreation.class);
      MiscUtil.statusMessage(player,"String_Node_Str");
    }
  }
 else   if (mapView != null) {
    Debugger.getDebugger().debug("String_Node_Str" + mapView.getMapView().getId() + "String_Node_Str"+ player.getName()+ "String_Node_Str"+ event.getAction()+ "String_Node_Str"+ mapView.getMenu().getName());
    if (block != null & block.getType() == Material.GLASS) {
      tryToDeactivateMap(block,player);
    }
 else     if (locView == null && block.getState() instanceof Sign) {
      tryToActivateSign(block,player,mapView);
    }
 else {
      SMSUserAction action=SMSUserAction.getAction(event);
      if (action != null) {
        action.execute(player,mapView);
      }
    }
  }
 else   if (block != null) {
    if (locView == null && block.getState() instanceof Sign && player.getItemInHand().getTypeId() == 0) {
      tryToActivateSign(block,player);
    }
 else     if (locView != null && player.getItemInHand().getType() == Material.MAP && !SMSMapView.usedByOtherPlugin(player.getItemInHand())) {
      tryToActivateMap(block,player);
    }
 else     if (locView != null) {
      Debugger.getDebugger().debug("String_Node_Str" + block.getLocation() + "String_Node_Str"+ player.getName()+ "String_Node_Str"+ event.getAction()+ "String_Node_Str"+ locView.getMenu().getName());
      SMSUserAction action=SMSUserAction.getAction(event);
      if (action != null) {
        action.execute(player,locView);
      }
    }
 else {
      return false;
    }
  }
  return true;
}

Fixed version (ground truth):
/** 
 * Main handler for PlayerInterfact events.
 * @param event		the event to handle
 * @return			true if the event has been handled and should be cancelled now, false otherwise
 * @throws SMSException	for any error that should be reported to the player
 */
private boolean handleInteraction(PlayerInteractEvent event) throws SMSException {
  Player player=event.getPlayer();
  Block block=event.getClickedBlock();
  SMSMapView mapView=player.getItemInHand().getType() == Material.MAP ? SMSMapView.getViewForId(player.getItemInHand().getDurability()) : null;
  if (block == null && mapView == null) {
    return false;
  }
  ScrollingMenuSign plugin=ScrollingMenuSign.getInstance();
  SMSView locView=block == null ? null : SMSView.getViewForLocation(block.getLocation());
  if (plugin.expecter.isExpecting(player,ExpectCommandSubstitution.class)) {
    plugin.expecter.cancelAction(player,ExpectCommandSubstitution.class);
    MiscUtil.alertMessage(player,"String_Node_Str");
  }
 else   if (plugin.expecter.isExpecting(player,ExpectViewCreation.class) && block != null) {
    if (event.getAction() == Action.LEFT_CLICK_BLOCK) {
      ExpectViewCreation c=(ExpectViewCreation)plugin.expecter.getAction(player,ExpectViewCreation.class);
      c.setLocation(block.getLocation());
      plugin.expecter.handleAction(player,c.getClass());
    }
 else     if (event.getAction() == Action.RIGHT_CLICK_BLOCK) {
      plugin.expecter.cancelAction(player,ExpectViewCreation.class);
      MiscUtil.statusMessage(player,"String_Node_Str");
    }
  }
 else   if (mapView != null) {
    Debugger.getDebugger().debug("String_Node_Str" + mapView.getMapView().getId() + "String_Node_Str"+ player.getName()+ "String_Node_Str"+ event.getAction()+ "String_Node_Str"+ mapView.getMenu().getName());
    if (block != null & block.getType() == Material.GLASS) {
      tryToDeactivateMap(block,player);
    }
 else     if (locView == null && block.getState() instanceof Sign) {
      tryToActivateSign(block,player,mapView);
    }
 else {
      SMSUserAction action=SMSUserAction.getAction(event);
      if (action != null) {
        action.execute(player,mapView);
      }
    }
  }
 else   if (block != null) {
    if (locView == null && block.getState() instanceof Sign && player.getItemInHand().getTypeId() == 0) {
      return tryToActivateSign(block,player);
    }
 else     if (locView != null && player.getItemInHand().getType() == Material.MAP && !SMSMapView.usedByOtherPlugin(player.getItemInHand())) {
      tryToActivateMap(block,player);
    }
 else     if (locView != null) {
      Debugger.getDebugger().debug("String_Node_Str" + block.getLocation() + "String_Node_Str"+ player.getName()+ "String_Node_Str"+ event.getAction()+ "String_Node_Str"+ locView.getMenu().getName());
      SMSUserAction action=SMSUserAction.getAction(event);
      if (action != null) {
        action.execute(player,locView);
      }
    }
 else {
      return false;
    }
  }
  return true;
}