Estoy intentando que una biblioteca de carga múltiple funcione para mi sitio web basado en Codeigniter. Lo tengo funcionando casi pero tengo un pequeño problema si subo más de una imagen, las extensiones de archivo se arruinan; por ejemplo, si subo tres JPEGS, obtengo esto en mi carpeta de subidas,

image1.jpg
image2.jpg.jpg
image3.jpg.jpg.jpg

No puedo ver lo que lo está causando, esta es la biblioteca en cuestión y estoy bastante seguro de que el problema es ahí,

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); 

/**
* This library assumes that you have already loaded the default CI Upload Library seperately
* 
* Functions is based upon CI_Upload, Feel free to modify this 
*   library to function as an extension to CI_Upload
* 
* Library modified by: Alvin Mites
* http://www.mitesdesign.com
* 
*/

class Multi_upload  {
    function Multi_upload () {
//      $CI =& get_instance();
    }

    /**
     * Perform multiple file uploads
     * Based upon JQuery Multiple Upload Class
     * see http://www.fyneworks.com/jquery/multiple-file-upload/
     */ 
    function go_upload($field = 'userfile') {
        $CI =& get_instance(); 
        // Is $_FILES[$field] set? If not, no reason to continue.
        if ( ! isset($_FILES[$field]['name'][0]))
        {
            $CI->upload->set_error('upload_no_file_selected');
            return FALSE;
        } else
        {
            $num_files = count($_FILES[$field]['name']) -1;
            $file_list = array();
            $error_hold = array();
            $error_upload = FALSE;
        }

        // Is the upload path valid?
        if ( ! $CI->upload->validate_upload_path())
        {
            // errors will already be set by validate_upload_path() so just return FALSE
            return FALSE;
        }

        for ($i=0; $i < $num_files; $i++) {

//          $fname = $_FILES[$field]['name'][$i];
//          echo "$fname\n\n<br><br>\n\n";

            $error_hold[$i] = FALSE;

            // Was the file able to be uploaded? If not, determine the reason why.
            if ( ! is_uploaded_file($_FILES[$field]['tmp_name'][$i]))
            {
                $error = ( ! isset($_FILES[$field]['error'][$i])) ? 4 : $_FILES[$field]['error'][$i];

                switch($error)
                {
                    case 1:  // UPLOAD_ERR_INI_SIZE
                        $error_hold[$i] = 'upload_file_exceeds_limit';
                        break;
                    case 2: // UPLOAD_ERR_FORM_SIZE
                        $error_hold[$i] = 'upload_file_exceeds_form_limit';
                        break;
                    case 3: // UPLOAD_ERR_PARTIAL
                       $error_hold[$i] = 'upload_file_partial';
                        break;
                    case 4: // UPLOAD_ERR_NO_FILE
                       $error_hold[$i] = 'upload_no_file_selected';
                        break;
                    case 6: // UPLOAD_ERR_NO_TMP_DIR
                        $error_hold[$i] = 'upload_no_temp_directory';
                        break;
                    case 7: // UPLOAD_ERR_CANT_WRITE
                        $error_hold[$i] = 'upload_unable_to_write_file';
                        break;
                    case 8: // UPLOAD_ERR_EXTENSION
                        $error_hold[$i] = 'upload_stopped_by_extension';
                        break;
                    default :
                        $error_hold[$i] = 'upload_no_file_selected';
                        break;
                }

                return FALSE;
            }

            // Set the uploaded data as class variables
            $CI->upload->file_temp = $_FILES[$field]['tmp_name'][$i];        
            $CI->upload->file_name = $CI->upload->_prep_filename($_FILES[$field]['name'][$i]);
            $CI->upload->file_size = $_FILES[$field]['size'][$i];        
            $CI->upload->file_type = preg_replace("/^(.+?);.*$/", "\\1", $_FILES[$field]['type'][$i]);
            $CI->upload->file_type = strtolower($CI->upload->file_type);
            $CI->upload->file_ext  = $CI->upload->get_extension($_FILES[$field]['name'][$i]);

            // Convert the file size to kilobytes
            if ($CI->upload->file_size > 0)
            {
                $CI->upload->file_size = round($CI->upload->file_size/1024, 2);
            }

            // Is the file type allowed to be uploaded?
            if ( ! $CI->upload->is_allowed_filetype())
            {
                $error_hold[$i] = 'upload_invalid_filetype';
            }

            // Is the file size within the allowed maximum?
            if ( ! $CI->upload->is_allowed_filesize())
            {
                $error_hold[$i] = 'upload_invalid_filesize';
            }

            // Are the image dimensions within the allowed size?
            // Note: This can fail if the server has an open_basdir restriction.
            if ( ! $CI->upload->is_allowed_dimensions())
            {
                $error_hold[$i] = 'upload_invalid_dimensions';
            }

            // Sanitize the file name for security
            $CI->upload->file_name = $CI->upload->clean_file_name($CI->upload->file_name);

            // Remove white spaces in the name
            if ($CI->upload->remove_spaces == TRUE)
            {
                $CI->upload->file_name = preg_replace("/\s+/", "_", $CI->upload->file_name);
            }

            /*
             * Validate the file name
             * This function appends an number onto the end of
             * the file if one with the same name already exists.
             * If it returns false there was a problem.
             */
            $CI->upload->orig_name = $CI->upload->file_name;

            if ($CI->upload->overwrite == FALSE)
            {
                $CI->upload->file_name = $CI->upload->set_filename($CI->upload->upload_path, $CI->upload->file_name);

                if ($CI->upload->file_name === FALSE)
                {
                    $error_hold[$i] = TRUE;
                }
            }

            /*
             * Move the file to the final destination
             * To deal with different server configurations
             * we'll attempt to use copy() first.  If that fails
             * we'll use move_uploaded_file().  One of the two should
             * reliably work in most environments
             */
            if ( ! @copy($CI->upload->file_temp, $CI->upload->upload_path.$CI->upload->file_name))
            {
                if ( ! @move_uploaded_file($CI->upload->file_temp, $CI->upload->upload_path.$CI->upload->file_name))
                {
                     $error_hold[$i] = 'upload_destination_error';
                }
            }

            /*
             * Run the file through the XSS hacking filter
             * This helps prevent malicious code from being
             * embedded within a file.  Scripts can easily
             * be disguised as images or other file types.
             */
            if ($CI->upload->xss_clean == TRUE)
            {
                $CI->upload->do_xss_clean();
            }

            if ($error_hold[$i]) {
                $error_upload = TRUE;

//                echo $error_hold[$i];
            } else {
                if ($imageVar = $this->multiple_image_properties($CI->upload->upload_path.$CI->upload->file_name)) {

                    $file_list[] = array(
                            'name' => $CI->upload->file_name,
                            'file' => $CI->upload->upload_path.$CI->upload->file_name,
                            'size' => $CI->upload->file_size,
                            'ext' => $CI->upload->file_ext,
                            'image_type' => $imageVar->image_type,
                            'height' => $imageVar->height,
                            'width' => $imageVar->width
                            );
                } else {
                    $file_list[] = array(
                            'name' => $CI->upload->file_name,
                            'file' => $CI->upload->upload_path.$CI->upload->file_name,
                            'size' => $CI->upload->file_size,
                            'type' => $CI->upload->file_type,
                            'ext' => $CI->upload->file_ext,
                            );
                }
            }

// For debugging
/*            
            if (strlen($error_hold[$i]) > 1) {
                    print_r($error_hold);
            }
*/            
        } // end for loop

        // Add error display for individual files        
        if ($error_upload) {
            $this->set_error($error_hold);
            return FALSE;
        } else {
            return $file_list;
        }    
    }

    // --------------------------------------------------------------------

    /**
     * Set Image Properties
     *
     * Uses GD to determine the width/height/type of image
     *
     * @access    public
     * @param    string
     * @return    void
     */    
    function multiple_image_properties($path = '')
    {
        $CI =& get_instance(); 
        if ( ! $CI->upload->is_image())
        {
            return false;
        }

        if (function_exists('getimagesize'))
        {
            if (FALSE !== ($D = @getimagesize($path)))
            {    
                $types = array(1 => 'gif', 2 => 'jpeg', 3 => 'png');

                $image->width       = $D['0'];
                $image->height      = $D['1'];
                $image->image_type        = ( ! isset($types[$D['2']])) ? 'unknown' : $types[$D['2']];

                return $image;
            }
        }
    }

    // --------------------------------------------------------------------

    /**
     * Set an error message
     *
     * @access    public
     * @param    string
     * @return    void
     */    
    function set_error($msg)
    {
        $CI =& get_instance();    
        $CI->lang->load('upload');

        if (is_array($msg))
        {
            foreach ($msg as $val)
            {
                $msg = ($CI->lang->line($val) == FALSE) ? $val : $CI->lang->line($val);                
                $this->error_msg[] = $msg;
                log_message('error', $msg);
            }        
        }
        else
        {
            $msg = ($CI->lang->line($msg) == FALSE) ? $msg : $CI->lang->line($msg);
            $this->error_msg[] = $msg;
            log_message('error', $msg);
        }
    }

    // --------------------------------------------------------------------
}
?>