media_upload_gallery

		// Set variables for storage, fix file filename for query strings.
		preg_match( '/[^\?]+\.(jpe?g|jpe|gif|png)\b/i', $file, $matches );

		if ( ! $matches ) {
			return new WP_Error( 'image_sideload_failed', __( 'Invalid image URL.' ) );
		}

		$file_array         = array();
		$file_array['name'] = wp_basename( $matches[0] );

		// Download file to temp location.
		$file_array['tmp_name'] = download_url( $file );

		// If error storing temporarily, return the error.
		if ( is_wp_error( $file_array['tmp_name'] ) ) {
			return $file_array['tmp_name'];