ru-se.com

revision.php (22542B)

---

 <?php
 /**
  * Post revision functions.
  *
  * @package WordPress
  * @subpackage Post_Revisions
  */
 
 /**
  * Determines which fields of posts are to be saved in revisions.
  *
  * @since 2.6.0
  * @since 4.5.0 A `WP_Post` object can now be passed to the `$post` parameter.
  * @since 4.5.0 The optional `$autosave` parameter was deprecated and renamed to `$deprecated`.
  * @access private
  *
  * @param array|WP_Post $post       Optional. A post array or a WP_Post object being processed
  *                                  for insertion as a post revision. Default empty array.
  * @param bool          $deprecated Not used.
  * @return array Array of fields that can be versioned.
  */
 function _wp_post_revision_fields( $post = array(), $deprecated = false ) {
 	static $fields = null;
 
 	if ( ! is_array( $post ) ) {
 		$post = get_post( $post, ARRAY_A );
 	}
 
 	if ( is_null( $fields ) ) {
 		// Allow these to be versioned.
 		$fields = array(
 			'post_title'   => __( 'Title' ),
 			'post_content' => __( 'Content' ),
 			'post_excerpt' => __( 'Excerpt' ),
 		);
 	}
 
 	/**
 	 * Filters the list of fields saved in post revisions.
 	 *
 	 * Included by default: 'post_title', 'post_content' and 'post_excerpt'.
 	 *
 	 * Disallowed fields: 'ID', 'post_name', 'post_parent', 'post_date',
 	 * 'post_date_gmt', 'post_status', 'post_type', 'comment_count',
 	 * and 'post_author'.
 	 *
 	 * @since 2.6.0
 	 * @since 4.5.0 The `$post` parameter was added.
 	 *
 	 * @param array $fields List of fields to revision. Contains 'post_title',
 	 *                      'post_content', and 'post_excerpt' by default.
 	 * @param array $post   A post array being processed for insertion as a post revision.
 	 */
 	$fields = apply_filters( '_wp_post_revision_fields', $fields, $post );
 
 	// WP uses these internally either in versioning or elsewhere - they cannot be versioned.
 	foreach ( array( 'ID', 'post_name', 'post_parent', 'post_date', 'post_date_gmt', 'post_status', 'post_type', 'comment_count', 'post_author' ) as $protect ) {
 		unset( $fields[ $protect ] );
 	}
 
 	return $fields;
 }
 
 /**
  * Returns a post array ready to be inserted into the posts table as a post revision.
  *
  * @since 4.5.0
  * @access private
  *
  * @param array|WP_Post $post     Optional. A post array or a WP_Post object to be processed
  *                                for insertion as a post revision. Default empty array.
  * @param bool          $autosave Optional. Is the revision an autosave? Default false.
  * @return array Post array ready to be inserted as a post revision.
  */
 function _wp_post_revision_data( $post = array(), $autosave = false ) {
 	if ( ! is_array( $post ) ) {
 		$post = get_post( $post, ARRAY_A );
 	}
 
 	$fields = _wp_post_revision_fields( $post );
 
 	$revision_data = array();
 
 	foreach ( array_intersect( array_keys( $post ), array_keys( $fields ) ) as $field ) {
 		$revision_data[ $field ] = $post[ $field ];
 	}
 
 	$revision_data['post_parent']   = $post['ID'];
 	$revision_data['post_status']   = 'inherit';
 	$revision_data['post_type']     = 'revision';
 	$revision_data['post_name']     = $autosave ? "$post[ID]-autosave-v1" : "$post[ID]-revision-v1"; // "1" is the revisioning system version.
 	$revision_data['post_date']     = isset( $post['post_modified'] ) ? $post['post_modified'] : '';
 	$revision_data['post_date_gmt'] = isset( $post['post_modified_gmt'] ) ? $post['post_modified_gmt'] : '';
 
 	return $revision_data;
 }
 
 /**
  * Creates a revision for the current version of a post.
  *
  * Typically used immediately after a post update, as every update is a revision,
  * and the most recent revision always matches the current post.
  *
  * @since 2.6.0
  *
  * @param int $post_id The ID of the post to save as a revision.
  * @return int|WP_Error|void Void or 0 if error, new revision ID, if success.
  */
 function wp_save_post_revision( $post_id ) {
 	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
 		return;
 	}
 
 	$post = get_post( $post_id );
 	if ( ! $post ) {
 		return;
 	}
 
 	if ( ! post_type_supports( $post->post_type, 'revisions' ) ) {
 		return;
 	}
 
 	if ( 'auto-draft' === $post->post_status ) {
 		return;
 	}
 
 	if ( ! wp_revisions_enabled( $post ) ) {
 		return;
 	}
 
 	/*
 	 * Compare the proposed update with the last stored revision verifying that
 	 * they are different, unless a plugin tells us to always save regardless.
 	 * If no previous revisions, save one.
 	 */
 	$revisions = wp_get_post_revisions( $post_id );
 	if ( $revisions ) {
 		// Grab the last revision, but not an autosave.
 		foreach ( $revisions as $revision ) {
 			if ( false !== strpos( $revision->post_name, "{$revision->post_parent}-revision" ) ) {
 				$last_revision = $revision;
 				break;
 			}
 		}
 
 		/**
 		 * Filters whether the post has changed since the last revision.
 		 *
 		 * By default a revision is saved only if one of the revisioned fields has changed.
 		 * This filter can override that so a revision is saved even if nothing has changed.
 		 *
 		 * @since 3.6.0
 		 *
 		 * @param bool    $check_for_changes Whether to check for changes before saving a new revision.
 		 *                                   Default true.
 		 * @param WP_Post $last_revision     The last revision post object.
 		 * @param WP_Post $post              The post object.
 		 */
 		if ( isset( $last_revision ) && apply_filters( 'wp_save_post_revision_check_for_changes', true, $last_revision, $post ) ) {
 			$post_has_changed = false;
 
 			foreach ( array_keys( _wp_post_revision_fields( $post ) ) as $field ) {
 				if ( normalize_whitespace( $post->$field ) !== normalize_whitespace( $last_revision->$field ) ) {
 					$post_has_changed = true;
 					break;
 				}
 			}
 
 			/**
 			 * Filters whether a post has changed.
 			 *
 			 * By default a revision is saved only if one of the revisioned fields has changed.
 			 * This filter allows for additional checks to determine if there were changes.
 			 *
 			 * @since 4.1.0
 			 *
 			 * @param bool    $post_has_changed Whether the post has changed.
 			 * @param WP_Post $last_revision    The last revision post object.
 			 * @param WP_Post $post             The post object.
 			 */
 			$post_has_changed = (bool) apply_filters( 'wp_save_post_revision_post_has_changed', $post_has_changed, $last_revision, $post );
 
 			// Don't save revision if post unchanged.
 			if ( ! $post_has_changed ) {
 				return;
 			}
 		}
 	}
 
 	$return = _wp_put_post_revision( $post );
 
 	// If a limit for the number of revisions to keep has been set,
 	// delete the oldest ones.
 	$revisions_to_keep = wp_revisions_to_keep( $post );
 
 	if ( $revisions_to_keep < 0 ) {
 		return $return;
 	}
 
 	$revisions = wp_get_post_revisions( $post_id, array( 'order' => 'ASC' ) );
 
 	$delete = count( $revisions ) - $revisions_to_keep;
 
 	if ( $delete < 1 ) {
 		return $return;
 	}
 
 	$revisions = array_slice( $revisions, 0, $delete );
 
 	for ( $i = 0; isset( $revisions[ $i ] ); $i++ ) {
 		if ( false !== strpos( $revisions[ $i ]->post_name, 'autosave' ) ) {
 			continue;
 		}
 
 		wp_delete_post_revision( $revisions[ $i ]->ID );
 	}
 
 	return $return;
 }
 
 /**
  * Retrieve the autosaved data of the specified post.
  *
  * Returns a post object with the information that was autosaved for the specified post.
  * If the optional $user_id is passed, returns the autosave for that user, otherwise
  * returns the latest autosave.
  *
  * @since 2.6.0
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param int $post_id The post ID.
  * @param int $user_id Optional The post author ID.
  * @return WP_Post|false The autosaved data or false on failure or when no autosave exists.
  */
 function wp_get_post_autosave( $post_id, $user_id = 0 ) {
 	global $wpdb;
 
 	$autosave_name = $post_id . '-autosave-v1';
 	$user_id_query = ( 0 !== $user_id ) ? "AND post_author = $user_id" : null;
 
 	// Construct the autosave query.
 	$autosave_query = "
 		SELECT *
 		FROM $wpdb->posts
 		WHERE post_parent = %d
 		AND post_type = 'revision'
 		AND post_status = 'inherit'
 		AND post_name   = %s " . $user_id_query . '
 		ORDER BY post_date DESC
 		LIMIT 1';
 
 	$autosave = $wpdb->get_results(
 		$wpdb->prepare(
 			$autosave_query,
 			$post_id,
 			$autosave_name
 		)
 	);
 
 	if ( ! $autosave ) {
 		return false;
 	}
 
 	return get_post( $autosave[0] );
 }
 
 /**
  * Determines if the specified post is a revision.
  *
  * @since 2.6.0
  *
  * @param int|WP_Post $post Post ID or post object.
  * @return int|false ID of revision's parent on success, false if not a revision.
  */
 function wp_is_post_revision( $post ) {
 	$post = wp_get_post_revision( $post );
 	if ( ! $post ) {
 		return false;
 	}
 
 	return (int) $post->post_parent;
 }
 
 /**
  * Determines if the specified post is an autosave.
  *
  * @since 2.6.0
  *
  * @param int|WP_Post $post Post ID or post object.
  * @return int|false ID of autosave's parent on success, false if not a revision.
  */
 function wp_is_post_autosave( $post ) {
 	$post = wp_get_post_revision( $post );
 	if ( ! $post ) {
 		return false;
 	}
 
 	if ( false !== strpos( $post->post_name, "{$post->post_parent}-autosave" ) ) {
 		return (int) $post->post_parent;
 	}
 
 	return false;
 }
 
 /**
  * Inserts post data into the posts table as a post revision.
  *
  * @since 2.6.0
  * @access private
  *
  * @param int|WP_Post|array|null $post     Post ID, post object OR post array.
  * @param bool                   $autosave Optional. Is the revision an autosave?
  * @return int|WP_Error WP_Error or 0 if error, new revision ID if success.
  */
 function _wp_put_post_revision( $post = null, $autosave = false ) {
 	if ( is_object( $post ) ) {
 		$post = get_object_vars( $post );
 	} elseif ( ! is_array( $post ) ) {
 		$post = get_post( $post, ARRAY_A );
 	}
 
 	if ( ! $post || empty( $post['ID'] ) ) {
 		return new WP_Error( 'invalid_post', __( 'Invalid post ID.' ) );
 	}
 
 	if ( isset( $post['post_type'] ) && 'revision' === $post['post_type'] ) {
 		return new WP_Error( 'post_type', __( 'Cannot create a revision of a revision' ) );
 	}
 
 	$post = _wp_post_revision_data( $post, $autosave );
 	$post = wp_slash( $post ); // Since data is from DB.
 
 	$revision_id = wp_insert_post( $post, true );
 	if ( is_wp_error( $revision_id ) ) {
 		return $revision_id;
 	}
 
 	if ( $revision_id ) {
 		/**
 		 * Fires once a revision has been saved.
 		 *
 		 * @since 2.6.0
 		 *
 		 * @param int $revision_id Post revision ID.
 		 */
 		do_action( '_wp_put_post_revision', $revision_id );
 	}
 
 	return $revision_id;
 }
 
 /**
  * Gets a post revision.
  *
  * @since 2.6.0
  *
  * @param int|WP_Post $post   The post ID or object.
  * @param string      $output Optional. The required return type. One of OBJECT, ARRAY_A, or ARRAY_N, which
  *                            correspond to a WP_Post object, an associative array, or a numeric array,
  *                            respectively. Default OBJECT.
  * @param string      $filter Optional sanitation filter. See sanitize_post().
  * @return WP_Post|array|null WP_Post (or array) on success, or null on failure.
  */
 function wp_get_post_revision( &$post, $output = OBJECT, $filter = 'raw' ) {
 	$revision = get_post( $post, OBJECT, $filter );
 	if ( ! $revision ) {
 		return $revision;
 	}
 	if ( 'revision' !== $revision->post_type ) {
 		return null;
 	}
 
 	if ( OBJECT === $output ) {
 		return $revision;
 	} elseif ( ARRAY_A === $output ) {
 		$_revision = get_object_vars( $revision );
 		return $_revision;
 	} elseif ( ARRAY_N === $output ) {
 		$_revision = array_values( get_object_vars( $revision ) );
 		return $_revision;
 	}
 
 	return $revision;
 }
 
 /**
  * Restores a post to the specified revision.
  *
  * Can restore a past revision using all fields of the post revision, or only selected fields.
  *
  * @since 2.6.0
  *
  * @param int|WP_Post $revision_id Revision ID or revision object.
  * @param array       $fields      Optional. What fields to restore from. Defaults to all.
  * @return int|false|null Null if error, false if no fields to restore, (int) post ID if success.
  */
 function wp_restore_post_revision( $revision_id, $fields = null ) {
 	$revision = wp_get_post_revision( $revision_id, ARRAY_A );
 	if ( ! $revision ) {
 		return $revision;
 	}
 
 	if ( ! is_array( $fields ) ) {
 		$fields = array_keys( _wp_post_revision_fields( $revision ) );
 	}
 
 	$update = array();
 	foreach ( array_intersect( array_keys( $revision ), $fields ) as $field ) {
 		$update[ $field ] = $revision[ $field ];
 	}
 
 	if ( ! $update ) {
 		return false;
 	}
 
 	$update['ID'] = $revision['post_parent'];
 
 	$update = wp_slash( $update ); // Since data is from DB.
 
 	$post_id = wp_update_post( $update );
 	if ( ! $post_id || is_wp_error( $post_id ) ) {
 		return $post_id;
 	}
 
 	// Update last edit user.
 	update_post_meta( $post_id, '_edit_last', get_current_user_id() );
 
 	/**
 	 * Fires after a post revision has been restored.
 	 *
 	 * @since 2.6.0
 	 *
 	 * @param int $post_id     Post ID.
 	 * @param int $revision_id Post revision ID.
 	 */
 	do_action( 'wp_restore_post_revision', $post_id, $revision['ID'] );
 
 	return $post_id;
 }
 
 /**
  * Deletes a revision.
  *
  * Deletes the row from the posts table corresponding to the specified revision.
  *
  * @since 2.6.0
  *
  * @param int|WP_Post $revision_id Revision ID or revision object.
  * @return array|false|WP_Post|WP_Error|null Null or WP_Error if error, deleted post if success.
  */
 function wp_delete_post_revision( $revision_id ) {
 	$revision = wp_get_post_revision( $revision_id );
 	if ( ! $revision ) {
 		return $revision;
 	}
 
 	$delete = wp_delete_post( $revision->ID );
 	if ( $delete ) {
 		/**
 		 * Fires once a post revision has been deleted.
 		 *
 		 * @since 2.6.0
 		 *
 		 * @param int     $revision_id Post revision ID.
 		 * @param WP_Post $revision    Post revision object.
 		 */
 		do_action( 'wp_delete_post_revision', $revision->ID, $revision );
 	}
 
 	return $delete;
 }
 
 /**
  * Returns all revisions of specified post.
  *
  * @since 2.6.0
  *
  * @see get_children()
  *
  * @param int|WP_Post $post_id Optional. Post ID or WP_Post object. Default is global `$post`.
  * @param array|null  $args    Optional. Arguments for retrieving post revisions. Default null.
  * @return array An array of revisions, or an empty array if none.
  */
 function wp_get_post_revisions( $post_id = 0, $args = null ) {
 	$post = get_post( $post_id );
 	if ( ! $post || empty( $post->ID ) ) {
 		return array();
 	}
 
 	$defaults = array(
 		'order'         => 'DESC',
 		'orderby'       => 'date ID',
 		'check_enabled' => true,
 	);
 	$args     = wp_parse_args( $args, $defaults );
 
 	if ( $args['check_enabled'] && ! wp_revisions_enabled( $post ) ) {
 		return array();
 	}
 
 	$args = array_merge(
 		$args,
 		array(
 			'post_parent' => $post->ID,
 			'post_type'   => 'revision',
 			'post_status' => 'inherit',
 		)
 	);
 
 	$revisions = get_children( $args );
 	if ( ! $revisions ) {
 		return array();
 	}
 
 	return $revisions;
 }
 
 /**
  * Determine if revisions are enabled for a given post.
  *
  * @since 3.6.0
  *
  * @param WP_Post $post The post object.
  * @return bool True if number of revisions to keep isn't zero, false otherwise.
  */
 function wp_revisions_enabled( $post ) {
 	return wp_revisions_to_keep( $post ) !== 0;
 }
 
 /**
  * Determine how many revisions to retain for a given post.
  *
  * By default, an infinite number of revisions are kept.
  *
  * The constant WP_POST_REVISIONS can be set in wp-config to specify the limit
  * of revisions to keep.
  *
  * @since 3.6.0
  *
  * @param WP_Post $post The post object.
  * @return int The number of revisions to keep.
  */
 function wp_revisions_to_keep( $post ) {
 	$num = WP_POST_REVISIONS;
 
 	if ( true === $num ) {
 		$num = -1;
 	} else {
 		$num = (int) $num;
 	}
 
 	if ( ! post_type_supports( $post->post_type, 'revisions' ) ) {
 		$num = 0;
 	}
 
 	/**
 	 * Filters the number of revisions to save for the given post.
 	 *
 	 * Overrides the value of WP_POST_REVISIONS.
 	 *
 	 * @since 3.6.0
 	 *
 	 * @param int     $num  Number of revisions to store.
 	 * @param WP_Post $post Post object.
 	 */
 	$num = apply_filters( 'wp_revisions_to_keep', $num, $post );
 
 	/**
 	 * Filters the number of revisions to save for the given post by its post type.
 	 *
 	 * Overrides both the value of WP_POST_REVISIONS and the {@see 'wp_revisions_to_keep'} filter.
 	 *
 	 * The dynamic portion of the hook name, `$post->post_type`, refers to
 	 * the post type slug.
 	 *
 	 * @since 5.8.0
 	 *
 	 * @param int     $num  Number of revisions to store.
 	 * @param WP_Post $post Post object.
 	 */
 	$num = apply_filters( "wp_{$post->post_type}_revisions_to_keep", $num, $post );
 
 	return (int) $num;
 }
 
 /**
  * Sets up the post object for preview based on the post autosave.
  *
  * @since 2.7.0
  * @access private
  *
  * @param WP_Post $post
  * @return WP_Post|false
  */
 function _set_preview( $post ) {
 	if ( ! is_object( $post ) ) {
 		return $post;
 	}
 
 	$preview = wp_get_post_autosave( $post->ID );
 	if ( ! is_object( $preview ) ) {
 		return $post;
 	}
 
 	$preview = sanitize_post( $preview );
 
 	$post->post_content = $preview->post_content;
 	$post->post_title   = $preview->post_title;
 	$post->post_excerpt = $preview->post_excerpt;
 
 	add_filter( 'get_the_terms', '_wp_preview_terms_filter', 10, 3 );
 	add_filter( 'get_post_metadata', '_wp_preview_post_thumbnail_filter', 10, 3 );
 
 	return $post;
 }
 
 /**
  * Filters the latest content for preview from the post autosave.
  *
  * @since 2.7.0
  * @access private
  */
 function _show_post_preview() {
 	if ( isset( $_GET['preview_id'] ) && isset( $_GET['preview_nonce'] ) ) {
 		$id = (int) $_GET['preview_id'];
 
 		if ( false === wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . $id ) ) {
 			wp_die( __( 'Sorry, you are not allowed to preview drafts.' ), 403 );
 		}
 
 		add_filter( 'the_preview', '_set_preview' );
 	}
 }
 
 /**
  * Filters terms lookup to set the post format.
  *
  * @since 3.6.0
  * @access private
  *
  * @param array  $terms
  * @param int    $post_id
  * @param string $taxonomy
  * @return array
  */
 function _wp_preview_terms_filter( $terms, $post_id, $taxonomy ) {
 	$post = get_post();
 	if ( ! $post ) {
 		return $terms;
 	}
 
 	if ( empty( $_REQUEST['post_format'] ) || $post->ID != $post_id
 		|| 'post_format' !== $taxonomy || 'revision' === $post->post_type
 	) {
 		return $terms;
 	}
 
 	if ( 'standard' === $_REQUEST['post_format'] ) {
 		$terms = array();
 	} else {
 		$term = get_term_by( 'slug', 'post-format-' . sanitize_key( $_REQUEST['post_format'] ), 'post_format' );
 		if ( $term ) {
 			$terms = array( $term ); // Can only have one post format.
 		}
 	}
 
 	return $terms;
 }
 
 /**
  * Filters post thumbnail lookup to set the post thumbnail.
  *
  * @since 4.6.0
  * @access private
  *
  * @param null|array|string $value    The value to return - a single metadata value, or an array of values.
  * @param int               $post_id  Post ID.
  * @param string            $meta_key Meta key.
  * @return null|array The default return value or the post thumbnail meta array.
  */
 function _wp_preview_post_thumbnail_filter( $value, $post_id, $meta_key ) {
 	$post = get_post();
 	if ( ! $post ) {
 		return $value;
 	}
 
 	if ( empty( $_REQUEST['_thumbnail_id'] ) ||
 		empty( $_REQUEST['preview_id'] ) ||
 		$post->ID != $post_id ||
 		'_thumbnail_id' !== $meta_key ||
 		'revision' === $post->post_type ||
 		$post_id != $_REQUEST['preview_id'] ) {
 
 		return $value;
 	}
 
 	$thumbnail_id = (int) $_REQUEST['_thumbnail_id'];
 	if ( $thumbnail_id <= 0 ) {
 		return '';
 	}
 
 	return (string) $thumbnail_id;
 }
 
 /**
  * Gets the post revision version.
  *
  * @since 3.6.0
  * @access private
  *
  * @param WP_Post $revision
  * @return int|false
  */
 function _wp_get_post_revision_version( $revision ) {
 	if ( is_object( $revision ) ) {
 		$revision = get_object_vars( $revision );
 	} elseif ( ! is_array( $revision ) ) {
 		return false;
 	}
 
 	if ( preg_match( '/^\d+-(?:autosave|revision)-v(\d+)$/', $revision['post_name'], $matches ) ) {
 		return (int) $matches[1];
 	}
 
 	return 0;
 }
 
 /**
  * Upgrade the revisions author, add the current post as a revision and set the revisions version to 1
  *
  * @since 3.6.0
  * @access private
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param WP_Post $post      Post object
  * @param array   $revisions Current revisions of the post
  * @return bool true if the revisions were upgraded, false if problems
  */
 function _wp_upgrade_revisions_of_post( $post, $revisions ) {
 	global $wpdb;
 
 	// Add post option exclusively.
 	$lock   = "revision-upgrade-{$post->ID}";
 	$now    = time();
 	$result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, 'no') /* LOCK */", $lock, $now ) );
 	if ( ! $result ) {
 		// If we couldn't get a lock, see how old the previous lock is.
 		$locked = get_option( $lock );
 		if ( ! $locked ) {
 			// Can't write to the lock, and can't read the lock.
 			// Something broken has happened.
 			return false;
 		}
 
 		if ( $locked > $now - 3600 ) {
 			// Lock is not too old: some other process may be upgrading this post. Bail.
 			return false;
 		}
 
 		// Lock is too old - update it (below) and continue.
 	}
 
 	// If we could get a lock, re-"add" the option to fire all the correct filters.
 	update_option( $lock, $now );
 
 	reset( $revisions );
 	$add_last = true;
 
 	do {
 		$this_revision = current( $revisions );
 		$prev_revision = next( $revisions );
 
 		$this_revision_version = _wp_get_post_revision_version( $this_revision );
 
 		// Something terrible happened.
 		if ( false === $this_revision_version ) {
 			continue;
 		}
 
 		// 1 is the latest revision version, so we're already up to date.
 		// No need to add a copy of the post as latest revision.
 		if ( 0 < $this_revision_version ) {
 			$add_last = false;
 			continue;
 		}
 
 		// Always update the revision version.
 		$update = array(
 			'post_name' => preg_replace( '/^(\d+-(?:autosave|revision))[\d-]*$/', '$1-v1', $this_revision->post_name ),
 		);
 
 		/*
 		 * If this revision is the oldest revision of the post, i.e. no $prev_revision,
 		 * the correct post_author is probably $post->post_author, but that's only a good guess.
 		 * Update the revision version only and Leave the author as-is.
 		 */
 		if ( $prev_revision ) {
 			$prev_revision_version = _wp_get_post_revision_version( $prev_revision );
 
 			// If the previous revision is already up to date, it no longer has the information we need :(
 			if ( $prev_revision_version < 1 ) {
 				$update['post_author'] = $prev_revision->post_author;
 			}
 		}
 
 		// Upgrade this revision.
 		$result = $wpdb->update( $wpdb->posts, $update, array( 'ID' => $this_revision->ID ) );
 
 		if ( $result ) {
 			wp_cache_delete( $this_revision->ID, 'posts' );
 		}
 	} while ( $prev_revision );
 
 	delete_option( $lock );
 
 	// Add a copy of the post as latest revision.
 	if ( $add_last ) {
 		wp_save_post_revision( $post->ID );
 	}
 
 	return true;
 }