apply_filters( 'attachment_fields_to_save', array $post, array $attachment )

803			 *804			 * @see wp_get_attachment_metadata()805			 *806			 * @param array $post       An array of post data.807			 * @param array $attachment An array of attachment metadata.808			 */809			$post = apply_filters( 'attachment_fields_to_save', $post, $attachment );810 811			if ( isset( $attachment['image_alt'] ) ) {812				$image_alt = wp_unslash( $attachment['image_alt'] );813 814				if ( get_post_meta( $attachment_id, '_wp_attachment_image_alt', true ) !== $image_alt ) {815					$image_alt = wp_strip_all_tags( $image_alt, true );