Reproducing crash caused by "clear()" in webdriver 1.8.x

fiddle.php

<?php

namespace Facebook\WebDriver;

use Facebook\WebDriver\Remote\DesiredCapabilities;
use Facebook\WebDriver\Remote\RemoteWebDriver;

require_once('vendor/autoload.php');

// Start Chrome in headless mode
// Chromedriver should already be running and listening.
$host = 'http://localhost:9515';
$capabilities = DesiredCapabilities::chrome();
$driver = RemoteWebDriver::create($host, $capabilities, 5000);

$driver->get('https://the-internet.herokuapp.com/login');

// Check page
echo "The title is '" . $driver->getTitle() . "'\n";

/*
 * Fills in login form - we simulate typing.
 *
 * Comment out both "clear() line to make login works / fails.
 *
 * Clear makes "sendKeys" fails, the value is not entered correctly:
 * either the whole string either some chars from end of string are "eaten".
 * Adding a "sleep()" does not help, it does not seem to be a timing issue.
 * The crash looks to be caused by lines 76-93 of RemoteWebElement::clear().
 * Replacing "WebDriverKeys::BACKSPACE" by "WebDriverKeys::DELETE" fixed it.
 */

$username = $driver->findElement(WebDriverBy::name('username'));
$username->clear(); // Comment to fix
$username->sendKeys('tomsmith');

// Password field
$password = $driver->findElement(WebDriverBy::name('password'));
$password->clear(); // Comment to fix
$password->sendKeys('SuperSecretPassword!');

$driver->takeScreenshot('before_login.png');

// We click on submit button
$driver->findElement(WebDriverBy::cssSelector('button[type="submit"]'))
    ->click();

if (!assert('https://the-internet.herokuapp.com/secure' === $driver->getCurrentURL(), 'Login failed')) {
    $driver->takeScreenshot('failure.png');
}

// close the browser
$driver->quit();