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    <h3>Editing: UrlMatcher.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Routing\Matcher;

use Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface;
use Symfony\Component\ExpressionLanguage\ExpressionLanguage;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Exception\MethodNotAllowedException;
use Symfony\Component\Routing\Exception\NoConfigurationException;
use Symfony\Component\Routing\Exception\ResourceNotFoundException;
use Symfony\Component\Routing\RequestContext;
use Symfony\Component\Routing\Route;
use Symfony\Component\Routing\RouteCollection;

/**
 * UrlMatcher matches URL based on a set of routes.
 *
 * @author Fabien Potencier &lt;fabien@symfony.com&gt;
 */
class UrlMatcher implements UrlMatcherInterface, RequestMatcherInterface
{
    public const REQUIREMENT_MATCH = 0;
    public const REQUIREMENT_MISMATCH = 1;
    public const ROUTE_MATCH = 2;

    /** @var RequestContext */
    protected $context;

    /**
     * Collects HTTP methods that would be allowed for the request.
     */
    protected $allow = [];

    /**
     * Collects URI schemes that would be allowed for the request.
     *
     * @internal
     */
    protected $allowSchemes = [];

    protected $routes;
    protected $request;
    protected $expressionLanguage;

    /**
     * @var ExpressionFunctionProviderInterface[]
     */
    protected $expressionLanguageProviders = [];

    public function __construct(RouteCollection $routes, RequestContext $context)
    {
        $this-&gt;routes = $routes;
        $this-&gt;context = $context;
    }

    /**
     * {@inheritdoc}
     */
    public function setContext(RequestContext $context)
    {
        $this-&gt;context = $context;
    }

    /**
     * {@inheritdoc}
     */
    public function getContext()
    {
        return $this-&gt;context;
    }

    /**
     * {@inheritdoc}
     */
    public function match(string $pathinfo)
    {
        $this-&gt;allow = $this-&gt;allowSchemes = [];

        if ($ret = $this-&gt;matchCollection(rawurldecode($pathinfo) ?: '/', $this-&gt;routes)) {
            return $ret;
        }

        if ('/' === $pathinfo &amp;&amp; !$this-&gt;allow &amp;&amp; !$this-&gt;allowSchemes) {
            throw new NoConfigurationException();
        }

        throw 0 &lt; \count($this-&gt;allow) ? new MethodNotAllowedException(array_unique($this-&gt;allow)) : new ResourceNotFoundException(sprintf('No routes found for &quot;%s&quot;.', $pathinfo));
    }

    /**
     * {@inheritdoc}
     */
    public function matchRequest(Request $request)
    {
        $this-&gt;request = $request;

        $ret = $this-&gt;match($request-&gt;getPathInfo());

        $this-&gt;request = null;

        return $ret;
    }

    public function addExpressionLanguageProvider(ExpressionFunctionProviderInterface $provider)
    {
        $this-&gt;expressionLanguageProviders[] = $provider;
    }

    /**
     * Tries to match a URL with a set of routes.
     *
     * @param string $pathinfo The path info to be parsed
     *
     * @return array
     *
     * @throws NoConfigurationException  If no routing configuration could be found
     * @throws ResourceNotFoundException If the resource could not be found
     * @throws MethodNotAllowedException If the resource was found but the request method is not allowed
     */
    protected function matchCollection(string $pathinfo, RouteCollection $routes)
    {
        // HEAD and GET are equivalent as per RFC
        if ('HEAD' === $method = $this-&gt;context-&gt;getMethod()) {
            $method = 'GET';
        }
        $supportsTrailingSlash = 'GET' === $method &amp;&amp; $this instanceof RedirectableUrlMatcherInterface;
        $trimmedPathinfo = rtrim($pathinfo, '/') ?: '/';

        foreach ($routes as $name =&gt; $route) {
            $compiledRoute = $route-&gt;compile();
            $staticPrefix = rtrim($compiledRoute-&gt;getStaticPrefix(), '/');
            $requiredMethods = $route-&gt;getMethods();

            // check the static prefix of the URL first. Only use the more expensive preg_match when it matches
            if ('' !== $staticPrefix &amp;&amp; !str_starts_with($trimmedPathinfo, $staticPrefix)) {
                continue;
            }
            $regex = $compiledRoute-&gt;getRegex();

            $pos = strrpos($regex, '$');
            $hasTrailingSlash = '/' === $regex[$pos - 1];
            $regex = substr_replace($regex, '/?$', $pos - $hasTrailingSlash, 1 + $hasTrailingSlash);

            if (!preg_match($regex, $pathinfo, $matches)) {
                continue;
            }

            $hasTrailingVar = $trimmedPathinfo !== $pathinfo &amp;&amp; preg_match('#\{\w+\}/?$#', $route-&gt;getPath());

            if ($hasTrailingVar &amp;&amp; ($hasTrailingSlash || (null === $m = $matches[\count($compiledRoute-&gt;getPathVariables())] ?? null) || '/' !== ($m[-1] ?? '/')) &amp;&amp; preg_match($regex, $trimmedPathinfo, $m)) {
                if ($hasTrailingSlash) {
                    $matches = $m;
                } else {
                    $hasTrailingVar = false;
                }
            }

            $hostMatches = [];
            if ($compiledRoute-&gt;getHostRegex() &amp;&amp; !preg_match($compiledRoute-&gt;getHostRegex(), $this-&gt;context-&gt;getHost(), $hostMatches)) {
                continue;
            }

            $status = $this-&gt;handleRouteRequirements($pathinfo, $name, $route);

            if (self::REQUIREMENT_MISMATCH === $status[0]) {
                continue;
            }

            if ('/' !== $pathinfo &amp;&amp; !$hasTrailingVar &amp;&amp; $hasTrailingSlash === ($trimmedPathinfo === $pathinfo)) {
                if ($supportsTrailingSlash &amp;&amp; (!$requiredMethods || \in_array('GET', $requiredMethods))) {
                    return $this-&gt;allow = $this-&gt;allowSchemes = [];
                }
                continue;
            }

            if ($route-&gt;getSchemes() &amp;&amp; !$route-&gt;hasScheme($this-&gt;context-&gt;getScheme())) {
                $this-&gt;allowSchemes = array_merge($this-&gt;allowSchemes, $route-&gt;getSchemes());
                continue;
            }

            if ($requiredMethods &amp;&amp; !\in_array($method, $requiredMethods)) {
                $this-&gt;allow = array_merge($this-&gt;allow, $requiredMethods);
                continue;
            }

            return $this-&gt;getAttributes($route, $name, array_replace($matches, $hostMatches, $status[1] ?? []));
        }

        return [];
    }

    /**
     * Returns an array of values to use as request attributes.
     *
     * As this method requires the Route object, it is not available
     * in matchers that do not have access to the matched Route instance
     * (like the PHP and Apache matcher dumpers).
     *
     * @return array
     */
    protected function getAttributes(Route $route, string $name, array $attributes)
    {
        $defaults = $route-&gt;getDefaults();
        if (isset($defaults['_canonical_route'])) {
            $name = $defaults['_canonical_route'];
            unset($defaults['_canonical_route']);
        }
        $attributes['_route'] = $name;

        return $this-&gt;mergeDefaults($attributes, $defaults);
    }

    /**
     * Handles specific route requirements.
     *
     * @return array The first element represents the status, the second contains additional information
     */
    protected function handleRouteRequirements(string $pathinfo, string $name, Route $route)
    {
        // expression condition
        if ($route-&gt;getCondition() &amp;&amp; !$this-&gt;getExpressionLanguage()-&gt;evaluate($route-&gt;getCondition(), ['context' =&gt; $this-&gt;context, 'request' =&gt; $this-&gt;request ?: $this-&gt;createRequest($pathinfo)])) {
            return [self::REQUIREMENT_MISMATCH, null];
        }

        return [self::REQUIREMENT_MATCH, null];
    }

    /**
     * Get merged default parameters.
     *
     * @return array
     */
    protected function mergeDefaults(array $params, array $defaults)
    {
        foreach ($params as $key =&gt; $value) {
            if (!\is_int($key) &amp;&amp; null !== $value) {
                $defaults[$key] = $value;
            }
        }

        return $defaults;
    }

    protected function getExpressionLanguage()
    {
        if (null === $this-&gt;expressionLanguage) {
            if (!class_exists(ExpressionLanguage::class)) {
                throw new \LogicException('Unable to use expressions as the Symfony ExpressionLanguage component is not installed.');
            }
            $this-&gt;expressionLanguage = new ExpressionLanguage(null, $this-&gt;expressionLanguageProviders);
        }

        return $this-&gt;expressionLanguage;
    }

    /**
     * @internal
     */
    protected function createRequest(string $pathinfo): ?Request
    {
        if (!class_exists(Request::class)) {
            return null;
        }

        return Request::create($this-&gt;context-&gt;getScheme().'://'.$this-&gt;context-&gt;getHost().$this-&gt;context-&gt;getBaseUrl().$pathinfo, $this-&gt;context-&gt;getMethod(), $this-&gt;context-&gt;getParameters(), [], [], [
            'SCRIPT_FILENAME' =&gt; $this-&gt;context-&gt;getBaseUrl(),
            'SCRIPT_NAME' =&gt; $this-&gt;context-&gt;getBaseUrl(),
        ]);
    }
}
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