Adding items to a list inside a timer sometimes results in "BUG" console warnings #118

*** BUG ***
In pixman_region32_init_rect: Invalid rectangle passed
Set a breakpoint on '_pixman_log_error' to debug

<?php

/**
 * Demo of refresh bug in list controls when amending them from a timer:
 *
 *      *** BUG ***
 *      In pixman_region32_init_rect: Invalid rectangle passed
 *      Set a breakpoint on '_pixman_log_error' to debug
 *
 * Does not help:
 *
 * - Creating the timer after the window is shown
 * - Letting the first timer event do nothing
 * - Disable the list control whilst it is being updated
 * - Refresh control after each change
 * - Disable or freeze control during changes
 *
 * This works:
 *
 * - Make control invisible whilst it is being updated
 */

// Create main window
$frame = new BackgroundPopulationFrame();
$frame->Show();

wxEntry();


class BackgroundPopulationFrame extends \wxFrame
{
    const FIX_BUG = false;
    // The bug seems to be subject to race conditions, so increase
    // this if you don't see warnings in the console
    const LOOP_COUNT = 10;

    protected $list;
    protected $timer;

    public function __construct($parent = null)
    {
        // Create a main window
        parent::__construct($parent, wxID_TOP, "Title");

        // Create a list control
        $this->list = new \wxListCtrl($this, wxID_ANY);
        $this->list->SetWindowStyleFlag(wxLC_REPORT);
        $this->list->InsertColumn(0, "Title");

        // Place window in centre of the screen
        $this->Centre(wxBOTH);

        // Start the background population
        $this->startPopulateTimer();
    }

    /**
     * Call a timer device to populate the list box
     */
    protected function startPopulateTimer()
    {
        $this->timer = new \wxTimer($this);
        $this->Connect(wxEVT_TIMER, array($this, "onTimer"));
        $this->timer->Start(50);
    }

    public function onTimer()
    {
        if (self::FIX_BUG)
        {
            #$this->list->Disable(); // Doesn't work
            #$this->list->Freeze(); // Doesn't work
            $this->list->Hide(); // Works but will be rather confusing for it to disappear
        }

        for($i = 0; $i < self::LOOP_COUNT; $i++)
        {
            $this->list->InsertItem($this->createCell($i, 0, "Title " . $i));
            #$this->list->Refresh(); // Doesn't work
        }

        $this->timer->Stop();

        if (self::FIX_BUG)
        {
            #$this->list->Enable(); // Doesn't work
            #$this->list->Thaw(); // Doesn't work
            $this->list->Show();
        }
    }

    protected function createCell($row, $column, $name)
    {
        $item = new \wxListItem();
        $item->SetId($row);
        $item->SetColumn($column);
        $item->SetText($name);

        return $item;
    }
}