<form method="POST">
    <h3>Editing: FileBag.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\HttpFoundation;

use Symfony\Component\HttpFoundation\File\UploadedFile;

/**
 * FileBag is a container for uploaded files.
 *
 * @author Fabien Potencier &lt;fabien@symfony.com&gt;
 * @author Bulat Shakirzyanov &lt;mallluhuct@gmail.com&gt;
 */
class FileBag extends ParameterBag
{
    private const FILE_KEYS = ['error', 'name', 'size', 'tmp_name', 'type'];

    /**
     * @param array|UploadedFile[] $parameters An array of HTTP files
     */
    public function __construct(array $parameters = [])
    {
        $this-&gt;replace($parameters);
    }

    /**
     * {@inheritdoc}
     */
    public function replace(array $files = [])
    {
        $this-&gt;parameters = [];
        $this-&gt;add($files);
    }

    /**
     * {@inheritdoc}
     */
    public function set(string $key, $value)
    {
        if (!\is_array($value) &amp;&amp; !$value instanceof UploadedFile) {
            throw new \InvalidArgumentException('An uploaded file must be an array or an instance of UploadedFile.');
        }

        parent::set($key, $this-&gt;convertFileInformation($value));
    }

    /**
     * {@inheritdoc}
     */
    public function add(array $files = [])
    {
        foreach ($files as $key =&gt; $file) {
            $this-&gt;set($key, $file);
        }
    }

    /**
     * Converts uploaded files to UploadedFile instances.
     *
     * @param array|UploadedFile $file A (multi-dimensional) array of uploaded file information
     *
     * @return UploadedFile[]|UploadedFile|null
     */
    protected function convertFileInformation($file)
    {
        if ($file instanceof UploadedFile) {
            return $file;
        }

        $file = $this-&gt;fixPhpFilesArray($file);
        $keys = array_keys($file);
        sort($keys);

        if (self::FILE_KEYS == $keys) {
            if (\UPLOAD_ERR_NO_FILE == $file['error']) {
                $file = null;
            } else {
                $file = new UploadedFile($file['tmp_name'], $file['name'], $file['type'], $file['error'], false);
            }
        } else {
            $file = array_map(function ($v) { return $v instanceof UploadedFile || \is_array($v) ? $this-&gt;convertFileInformation($v) : $v; }, $file);
            if (array_keys($keys) === $keys) {
                $file = array_filter($file);
            }
        }

        return $file;
    }

    /**
     * Fixes a malformed PHP $_FILES array.
     *
     * PHP has a bug that the format of the $_FILES array differs, depending on
     * whether the uploaded file fields had normal field names or array-like
     * field names (&quot;normal&quot; vs. &quot;parent[child]&quot;).
     *
     * This method fixes the array to look like the &quot;normal&quot; $_FILES array.
     *
     * It's safe to pass an already converted array, in which case this method
     * just returns the original array unmodified.
     *
     * @return array
     */
    protected function fixPhpFilesArray(array $data)
    {
        // Remove extra key added by PHP 8.1.
        unset($data['full_path']);
        $keys = array_keys($data);
        sort($keys);

        if (self::FILE_KEYS != $keys || !isset($data['name']) || !\is_array($data['name'])) {
            return $data;
        }

        $files = $data;
        foreach (self::FILE_KEYS as $k) {
            unset($files[$k]);
        }

        foreach ($data['name'] as $key =&gt; $name) {
            $files[$key] = $this-&gt;fixPhpFilesArray([
                'error' =&gt; $data['error'][$key],
                'name' =&gt; $name,
                'type' =&gt; $data['type'][$key],
                'tmp_name' =&gt; $data['tmp_name'][$key],
                'size' =&gt; $data['size'][$key],
            ]);
        }

        return $files;
    }
}
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