wp/wp-includes/revision.php
changeset 0 d970ebf37754
child 5 5e2f62d02dcd
equal deleted inserted replaced
-1:000000000000 0:d970ebf37754
       
     1 <?php
       
     2 /**
       
     3  * Post revision functions.
       
     4  *
       
     5  * @package WordPress
       
     6  * @subpackage Post_Revisions
       
     7  */
       
     8 
       
     9 /**
       
    10  * Determines which fields of posts are to be saved in revisions.
       
    11  *
       
    12  * Does two things. If passed a post *array*, it will return a post array ready
       
    13  * to be inserted into the posts table as a post revision. Otherwise, returns
       
    14  * an array whose keys are the post fields to be saved for post revisions.
       
    15  *
       
    16  * @since 2.6.0
       
    17  * @access private
       
    18  *
       
    19  * @uses apply_filters() Calls '_wp_post_revision_fields' on 'title', 'content' and 'excerpt' fields.
       
    20  *
       
    21  * @param array $post Optional a post array to be processed for insertion as a post revision.
       
    22  * @param bool $autosave optional Is the revision an autosave?
       
    23  * @return array Post array ready to be inserted as a post revision or array of fields that can be versioned.
       
    24  */
       
    25 function _wp_post_revision_fields( $post = null, $autosave = false ) {
       
    26 	static $fields = false;
       
    27 
       
    28 	if ( !$fields ) {
       
    29 		// Allow these to be versioned
       
    30 		$fields = array(
       
    31 			'post_title' => __( 'Title' ),
       
    32 			'post_content' => __( 'Content' ),
       
    33 			'post_excerpt' => __( 'Excerpt' ),
       
    34 		);
       
    35 
       
    36 		// Runs only once
       
    37 		$fields = apply_filters( '_wp_post_revision_fields', $fields );
       
    38 
       
    39 		// WP uses these internally either in versioning or elsewhere - they cannot be versioned
       
    40 		foreach ( array( 'ID', 'post_name', 'post_parent', 'post_date', 'post_date_gmt', 'post_status', 'post_type', 'comment_count', 'post_author' ) as $protect )
       
    41 			unset( $fields[$protect] );
       
    42 	}
       
    43 
       
    44 	if ( !is_array($post) )
       
    45 		return $fields;
       
    46 
       
    47 	$return = array();
       
    48 	foreach ( array_intersect( array_keys( $post ), array_keys( $fields ) ) as $field )
       
    49 		$return[$field] = $post[$field];
       
    50 
       
    51 	$return['post_parent']   = $post['ID'];
       
    52 	$return['post_status']   = 'inherit';
       
    53 	$return['post_type']     = 'revision';
       
    54 	$return['post_name']     = $autosave ? "$post[ID]-autosave-v1" : "$post[ID]-revision-v1"; // "1" is the revisioning system version
       
    55 	$return['post_date']     = isset($post['post_modified']) ? $post['post_modified'] : '';
       
    56 	$return['post_date_gmt'] = isset($post['post_modified_gmt']) ? $post['post_modified_gmt'] : '';
       
    57 
       
    58 	return $return;
       
    59 }
       
    60 
       
    61 /**
       
    62  * Saves an already existing post as a post revision.
       
    63  *
       
    64  * Typically used immediately after post updates.
       
    65  * Adds a copy of the current post as a revision, so latest revision always matches current post
       
    66  *
       
    67  * @since 2.6.0
       
    68  *
       
    69  * @uses _wp_put_post_revision()
       
    70  *
       
    71  * @param int $post_id The ID of the post to save as a revision.
       
    72  * @return mixed Null or 0 if error, new revision ID, if success.
       
    73  */
       
    74 function wp_save_post_revision( $post_id ) {
       
    75 	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
       
    76 		return;
       
    77 
       
    78 	if ( ! $post = get_post( $post_id ) )
       
    79 		return;
       
    80 
       
    81 	if ( ! post_type_supports( $post->post_type, 'revisions' ) )
       
    82 		return;
       
    83 
       
    84 	if ( 'auto-draft' == $post->post_status )
       
    85 		return;
       
    86 
       
    87 	if ( ! wp_revisions_enabled( $post ) )
       
    88 		return;
       
    89 
       
    90 	// Compare the proposed update with the last stored revision verifying that
       
    91 	// they are different, unless a plugin tells us to always save regardless.
       
    92 	// If no previous revisions, save one
       
    93 	if ( $revisions = wp_get_post_revisions( $post_id ) ) {
       
    94 		// grab the last revision, but not an autosave
       
    95 		foreach ( $revisions as $revision ) {
       
    96 			if ( false !== strpos( $revision->post_name, "{$revision->post_parent}-revision" ) ) {
       
    97 				$last_revision = $revision;
       
    98 				break;
       
    99 			}
       
   100 		}
       
   101 
       
   102 		if ( isset( $last_revision ) && apply_filters( 'wp_save_post_revision_check_for_changes', true, $last_revision, $post ) ) {
       
   103 			$post_has_changed = false;
       
   104 
       
   105 			foreach ( array_keys( _wp_post_revision_fields() ) as $field ) {
       
   106 				if ( normalize_whitespace( $post->$field ) != normalize_whitespace( $last_revision->$field ) ) {
       
   107 					$post_has_changed = true;
       
   108 					break;
       
   109 				}
       
   110 			}
       
   111 			//don't save revision if post unchanged
       
   112 			if( ! $post_has_changed )
       
   113 				return;
       
   114 		}
       
   115 	}
       
   116 
       
   117 	$return = _wp_put_post_revision( $post );
       
   118 
       
   119 	$revisions_to_keep = wp_revisions_to_keep( $post );
       
   120 
       
   121 	if ( $revisions_to_keep < 0 )
       
   122 		return $return;
       
   123 
       
   124 	// all revisions and autosaves
       
   125 	$revisions = wp_get_post_revisions( $post_id, array( 'order' => 'ASC' ) );
       
   126 
       
   127 	$delete = count($revisions) - $revisions_to_keep;
       
   128 
       
   129 	if ( $delete < 1 )
       
   130 		return $return;
       
   131 
       
   132 	$revisions = array_slice( $revisions, 0, $delete );
       
   133 
       
   134 	for ( $i = 0; isset( $revisions[$i] ); $i++ ) {
       
   135 		if ( false !== strpos( $revisions[ $i ]->post_name, 'autosave' ) )
       
   136 			continue;
       
   137 
       
   138 		wp_delete_post_revision( $revisions[ $i ]->ID );
       
   139 	}
       
   140 
       
   141 	return $return;
       
   142 }
       
   143 
       
   144 /**
       
   145  * Retrieve the autosaved data of the specified post.
       
   146  *
       
   147  * Returns a post object containing the information that was autosaved for the
       
   148  * specified post. If the optional $user_id is passed, returns the autosave for that user
       
   149  * otherwise returns the latest autosave.
       
   150  *
       
   151  * @since 2.6.0
       
   152  *
       
   153  * @uses wp_get_post_revisions()
       
   154  *
       
   155  * @param int $post_id The post ID.
       
   156  * @param int $user_id optional The post author ID.
       
   157  * @return object|bool The autosaved data or false on failure or when no autosave exists.
       
   158  */
       
   159 function wp_get_post_autosave( $post_id, $user_id = 0 ) {
       
   160 	$revisions = wp_get_post_revisions( $post_id, array( 'check_enabled' => false ) );
       
   161 
       
   162 	foreach ( $revisions as $revision ) {
       
   163 		if ( false !== strpos( $revision->post_name, "{$post_id}-autosave" ) ) {
       
   164 			if ( $user_id && $user_id != $revision->post_author )
       
   165 				continue;
       
   166 
       
   167 			return $revision;
       
   168 			break;
       
   169 		}
       
   170 	}
       
   171 
       
   172 	return false;
       
   173 }
       
   174 
       
   175 /**
       
   176  * Determines if the specified post is a revision.
       
   177  *
       
   178  * @since 2.6.0
       
   179  *
       
   180  * @param int|object $post Post ID or post object.
       
   181  * @return bool|int False if not a revision, ID of revision's parent otherwise.
       
   182  */
       
   183 function wp_is_post_revision( $post ) {
       
   184 	if ( !$post = wp_get_post_revision( $post ) )
       
   185 		return false;
       
   186 
       
   187 	return (int) $post->post_parent;
       
   188 }
       
   189 
       
   190 /**
       
   191  * Determines if the specified post is an autosave.
       
   192  *
       
   193  * @since 2.6.0
       
   194  *
       
   195  * @param int|object $post Post ID or post object.
       
   196  * @return bool|int False if not a revision, ID of autosave's parent otherwise
       
   197  */
       
   198 function wp_is_post_autosave( $post ) {
       
   199 	if ( !$post = wp_get_post_revision( $post ) )
       
   200 		return false;
       
   201 
       
   202 	if ( false !== strpos( $post->post_name, "{$post->post_parent}-autosave" ) )
       
   203 		return (int) $post->post_parent;
       
   204 
       
   205 	return false;
       
   206 }
       
   207 
       
   208 /**
       
   209  * Inserts post data into the posts table as a post revision.
       
   210  *
       
   211  * @since 2.6.0
       
   212  * @access private
       
   213  *
       
   214  * @uses wp_insert_post()
       
   215  *
       
   216  * @param int|object|array $post Post ID, post object OR post array.
       
   217  * @param bool $autosave Optional. Is the revision an autosave?
       
   218  * @return mixed Null or 0 if error, new revision ID if success.
       
   219  */
       
   220 function _wp_put_post_revision( $post = null, $autosave = false ) {
       
   221 	if ( is_object($post) )
       
   222 		$post = get_object_vars( $post );
       
   223 	elseif ( !is_array($post) )
       
   224 		$post = get_post($post, ARRAY_A);
       
   225 
       
   226 	if ( !$post || empty($post['ID']) )
       
   227 		return;
       
   228 
       
   229 	if ( isset($post['post_type']) && 'revision' == $post['post_type'] )
       
   230 		return new WP_Error( 'post_type', __( 'Cannot create a revision of a revision' ) );
       
   231 
       
   232 	$post_id = $post['ID'];
       
   233 	$post = _wp_post_revision_fields( $post, $autosave );
       
   234 	$post = wp_slash($post); //since data is from db
       
   235 
       
   236 	$revision_id = wp_insert_post( $post );
       
   237 	if ( is_wp_error($revision_id) )
       
   238 		return $revision_id;
       
   239 
       
   240 	if ( $revision_id )
       
   241 		do_action( '_wp_put_post_revision', $revision_id );
       
   242 
       
   243 	return $revision_id;
       
   244 }
       
   245 
       
   246 /**
       
   247  * Gets a post revision.
       
   248  *
       
   249  * @since 2.6.0
       
   250  *
       
   251  * @uses get_post()
       
   252  *
       
   253  * @param int|object $post The post ID or object.
       
   254  * @param string $output Optional. OBJECT, ARRAY_A, or ARRAY_N.
       
   255  * @param string $filter Optional sanitation filter. @see sanitize_post().
       
   256  * @return mixed Null if error or post object if success.
       
   257  */
       
   258 function wp_get_post_revision(&$post, $output = OBJECT, $filter = 'raw') {
       
   259 	$null = null;
       
   260 	if ( !$revision = get_post( $post, OBJECT, $filter ) )
       
   261 		return $revision;
       
   262 	if ( 'revision' !== $revision->post_type )
       
   263 		return $null;
       
   264 
       
   265 	if ( $output == OBJECT ) {
       
   266 		return $revision;
       
   267 	} elseif ( $output == ARRAY_A ) {
       
   268 		$_revision = get_object_vars($revision);
       
   269 		return $_revision;
       
   270 	} elseif ( $output == ARRAY_N ) {
       
   271 		$_revision = array_values(get_object_vars($revision));
       
   272 		return $_revision;
       
   273 	}
       
   274 
       
   275 	return $revision;
       
   276 }
       
   277 
       
   278 /**
       
   279  * Restores a post to the specified revision.
       
   280  *
       
   281  * Can restore a past revision using all fields of the post revision, or only selected fields.
       
   282  *
       
   283  * @since 2.6.0
       
   284  *
       
   285  * @uses wp_get_post_revision()
       
   286  * @uses wp_update_post()
       
   287  * @uses do_action() Calls 'wp_restore_post_revision' on post ID and revision ID if wp_update_post()
       
   288  *  is successful.
       
   289  *
       
   290  * @param int|object $revision_id Revision ID or revision object.
       
   291  * @param array $fields Optional. What fields to restore from. Defaults to all.
       
   292  * @return mixed Null if error, false if no fields to restore, (int) post ID if success.
       
   293  */
       
   294 function wp_restore_post_revision( $revision_id, $fields = null ) {
       
   295 	if ( !$revision = wp_get_post_revision( $revision_id, ARRAY_A ) )
       
   296 		return $revision;
       
   297 
       
   298 	if ( !is_array( $fields ) )
       
   299 		$fields = array_keys( _wp_post_revision_fields() );
       
   300 
       
   301 	$update = array();
       
   302 	foreach( array_intersect( array_keys( $revision ), $fields ) as $field ) {
       
   303 		$update[$field] = $revision[$field];
       
   304 	}
       
   305 
       
   306 	if ( !$update )
       
   307 		return false;
       
   308 
       
   309 	$update['ID'] = $revision['post_parent'];
       
   310 
       
   311 	$update = wp_slash( $update ); //since data is from db
       
   312 
       
   313 	$post_id = wp_update_post( $update );
       
   314 	if ( ! $post_id || is_wp_error( $post_id ) )
       
   315 		return $post_id;
       
   316 
       
   317 	// Add restore from details
       
   318 	$restore_details = array(
       
   319 		'restored_revision_id' => $revision_id,
       
   320 		'restored_by_user'     => get_current_user_id(),
       
   321 		'restored_time'        => time()
       
   322 	);
       
   323 	update_post_meta( $post_id, '_post_restored_from', $restore_details );
       
   324 
       
   325 	// Update last edit user
       
   326 	update_post_meta( $post_id, '_edit_last', get_current_user_id() );
       
   327 
       
   328 	do_action( 'wp_restore_post_revision', $post_id, $revision['ID'] );
       
   329 
       
   330 	return $post_id;
       
   331 }
       
   332 
       
   333 /**
       
   334  * Deletes a revision.
       
   335  *
       
   336  * Deletes the row from the posts table corresponding to the specified revision.
       
   337  *
       
   338  * @since 2.6.0
       
   339  *
       
   340  * @uses wp_get_post_revision()
       
   341  * @uses wp_delete_post()
       
   342  *
       
   343  * @param int|object $revision_id Revision ID or revision object.
       
   344  * @return mixed Null or WP_Error if error, deleted post if success.
       
   345  */
       
   346 function wp_delete_post_revision( $revision_id ) {
       
   347 	if ( !$revision = wp_get_post_revision( $revision_id ) )
       
   348 		return $revision;
       
   349 
       
   350 	$delete = wp_delete_post( $revision->ID );
       
   351 	if ( is_wp_error( $delete ) )
       
   352 		return $delete;
       
   353 
       
   354 	if ( $delete )
       
   355 		do_action( 'wp_delete_post_revision', $revision->ID, $revision );
       
   356 
       
   357 	return $delete;
       
   358 }
       
   359 
       
   360 /**
       
   361  * Returns all revisions of specified post.
       
   362  *
       
   363  * @since 2.6.0
       
   364  *
       
   365  * @uses get_children()
       
   366  *
       
   367  * @param int|object $post_id Post ID or post object
       
   368  * @return array An array of revisions, or an empty array if none.
       
   369  */
       
   370 function wp_get_post_revisions( $post_id = 0, $args = null ) {
       
   371 	$post = get_post( $post_id );
       
   372 	if ( ! $post || empty( $post->ID ) )
       
   373 		return array();
       
   374 
       
   375 	$defaults = array( 'order' => 'DESC', 'orderby' => 'date', 'check_enabled' => true );
       
   376 	$args = wp_parse_args( $args, $defaults );
       
   377 
       
   378 	if ( $args['check_enabled'] && ! wp_revisions_enabled( $post ) )
       
   379 		return array();
       
   380 
       
   381 	$args = array_merge( $args, array( 'post_parent' => $post->ID, 'post_type' => 'revision', 'post_status' => 'inherit' ) );
       
   382 
       
   383 	if ( ! $revisions = get_children( $args ) )
       
   384 		return array();
       
   385 
       
   386 	return $revisions;
       
   387 }
       
   388 
       
   389 /**
       
   390  * Determine if revisions are enabled for a given post.
       
   391  *
       
   392  * @since 3.6.0
       
   393  *
       
   394  * @uses wp_revisions_to_keep()
       
   395  *
       
   396  * @param object $post The post object.
       
   397  * @return bool True if number of revisions to keep isn't zero, false otherwise.
       
   398  */
       
   399 function wp_revisions_enabled( $post ) {
       
   400 	return wp_revisions_to_keep( $post ) != 0;
       
   401 }
       
   402 
       
   403 /**
       
   404  * Determine how many revisions to retain for a given post.
       
   405  * By default, an infinite number of revisions are stored if a post type supports revisions.
       
   406  *
       
   407  * @since 3.6.0
       
   408  *
       
   409  * @uses post_type_supports()
       
   410  * @uses apply_filters() Calls 'wp_revisions_to_keep' hook on the number of revisions.
       
   411  *
       
   412  * @param object $post The post object.
       
   413  * @return int The number of revisions to keep.
       
   414  */
       
   415 function wp_revisions_to_keep( $post ) {
       
   416 	$num = WP_POST_REVISIONS;
       
   417 
       
   418 	if ( true === $num )
       
   419 		$num = -1;
       
   420 	else
       
   421 		$num = intval( $num );
       
   422 
       
   423 	if ( ! post_type_supports( $post->post_type, 'revisions' ) )
       
   424 		$num = 0;
       
   425 
       
   426 	return (int) apply_filters( 'wp_revisions_to_keep', $num, $post );
       
   427 }
       
   428 
       
   429 /**
       
   430  * Sets up the post object for preview based on the post autosave.
       
   431  *
       
   432  * @since 2.7.0
       
   433  * @access private
       
   434  */
       
   435 function _set_preview($post) {
       
   436 
       
   437 	if ( ! is_object($post) )
       
   438 		return $post;
       
   439 
       
   440 	$preview = wp_get_post_autosave($post->ID);
       
   441 
       
   442 	if ( ! is_object($preview) )
       
   443 		return $post;
       
   444 
       
   445 	$preview = sanitize_post($preview);
       
   446 
       
   447 	$post->post_content = $preview->post_content;
       
   448 	$post->post_title = $preview->post_title;
       
   449 	$post->post_excerpt = $preview->post_excerpt;
       
   450 
       
   451 	add_filter( 'get_the_terms', '_wp_preview_terms_filter', 10, 3 );
       
   452 
       
   453 	return $post;
       
   454 }
       
   455 
       
   456 /**
       
   457  * Filters the latest content for preview from the post autosave.
       
   458  *
       
   459  * @since 2.7.0
       
   460  * @access private
       
   461  */
       
   462 function _show_post_preview() {
       
   463 
       
   464 	if ( isset($_GET['preview_id']) && isset($_GET['preview_nonce']) ) {
       
   465 		$id = (int) $_GET['preview_id'];
       
   466 
       
   467 		if ( false == wp_verify_nonce( $_GET['preview_nonce'], 'post_preview_' . $id ) )
       
   468 			wp_die( __('You do not have permission to preview drafts.') );
       
   469 
       
   470 		add_filter('the_preview', '_set_preview');
       
   471 	}
       
   472 }
       
   473 
       
   474 /**
       
   475  * Filters terms lookup to set the post format.
       
   476  *
       
   477  * @since 3.6.0
       
   478  * @access private
       
   479  */
       
   480 function _wp_preview_terms_filter( $terms, $post_id, $taxonomy ) {
       
   481 	if ( ! $post = get_post() )
       
   482 		return $terms;
       
   483 
       
   484 	if ( empty( $_REQUEST['post_format'] ) || $post->ID != $post_id || 'post_format' != $taxonomy || 'revision' == $post->post_type )
       
   485 		return $terms;
       
   486 
       
   487 	if ( 'standard' == $_REQUEST['post_format'] )
       
   488 		$terms = array();
       
   489 	elseif ( $term = get_term_by( 'slug', 'post-format-' . sanitize_key( $_REQUEST['post_format'] ), 'post_format' ) )
       
   490 		$terms = array( $term ); // Can only have one post format
       
   491 
       
   492 	return $terms;
       
   493 }
       
   494 
       
   495 /**
       
   496  * Gets the post revision version.
       
   497  *
       
   498  * @since 3.6.0
       
   499  * @access private
       
   500 */
       
   501 function _wp_get_post_revision_version( $revision ) {
       
   502 	if ( is_object( $revision ) )
       
   503 		$revision = get_object_vars( $revision );
       
   504 	elseif ( !is_array( $revision ) )
       
   505 		return false;
       
   506 
       
   507 	if ( preg_match( '/^\d+-(?:autosave|revision)-v(\d+)$/', $revision['post_name'], $matches ) )
       
   508 		return (int) $matches[1];
       
   509 
       
   510 	return 0;
       
   511 }
       
   512 
       
   513 /**
       
   514  * Upgrade the revisions author, add the current post as a revision and set the revisions version to 1
       
   515  *
       
   516  * @since 3.6.0
       
   517  * @access private
       
   518  *
       
   519  * @uses wp_get_post_revisions()
       
   520  *
       
   521  * @param object $post Post object
       
   522  * @param array $revisions Current revisions of the post
       
   523  * @return bool true if the revisions were upgraded, false if problems
       
   524  */
       
   525 function _wp_upgrade_revisions_of_post( $post, $revisions ) {
       
   526 	global $wpdb;
       
   527 
       
   528 	// Add post option exclusively
       
   529 	$lock = "revision-upgrade-{$post->ID}";
       
   530 	$now = time();
       
   531 	$result = $wpdb->query( $wpdb->prepare( "INSERT IGNORE INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, 'no') /* LOCK */", $lock, $now ) );
       
   532 	if ( ! $result ) {
       
   533 		// If we couldn't get a lock, see how old the previous lock is
       
   534 		$locked = get_option( $lock );
       
   535 		if ( ! $locked ) {
       
   536 			// Can't write to the lock, and can't read the lock.
       
   537 			// Something broken has happened
       
   538 			return false;
       
   539 		}
       
   540 
       
   541 		if ( $locked > $now - 3600 ) {
       
   542 			// Lock is not too old: some other process may be upgrading this post.  Bail.
       
   543 			return false;
       
   544 		}
       
   545 
       
   546 		// Lock is too old - update it (below) and continue
       
   547 	}
       
   548 
       
   549 	// If we could get a lock, re-"add" the option to fire all the correct filters.
       
   550 	update_option( $lock, $now );
       
   551 
       
   552 	reset( $revisions );
       
   553 	$add_last = true;
       
   554 
       
   555 	do {
       
   556 		$this_revision = current( $revisions );
       
   557 		$prev_revision = next( $revisions );
       
   558 
       
   559 		$this_revision_version = _wp_get_post_revision_version( $this_revision );
       
   560 
       
   561 		// Something terrible happened
       
   562 		if ( false === $this_revision_version )
       
   563 			continue;
       
   564 
       
   565 		// 1 is the latest revision version, so we're already up to date.
       
   566 		// No need to add a copy of the post as latest revision.
       
   567 		if ( 0 < $this_revision_version ) {
       
   568 			$add_last = false;
       
   569 			continue;
       
   570 		}
       
   571 
       
   572 		// Always update the revision version
       
   573 		$update = array(
       
   574 			'post_name' => preg_replace( '/^(\d+-(?:autosave|revision))[\d-]*$/', '$1-v1', $this_revision->post_name ),
       
   575 		);
       
   576 
       
   577 		// If this revision is the oldest revision of the post, i.e. no $prev_revision,
       
   578 		// the correct post_author is probably $post->post_author, but that's only a good guess.
       
   579 		// Update the revision version only and Leave the author as-is.
       
   580 		if ( $prev_revision ) {
       
   581 			$prev_revision_version = _wp_get_post_revision_version( $prev_revision );
       
   582 
       
   583 			// If the previous revision is already up to date, it no longer has the information we need :(
       
   584 			if ( $prev_revision_version < 1 )
       
   585 				$update['post_author'] = $prev_revision->post_author;
       
   586 		}
       
   587 
       
   588 		// Upgrade this revision
       
   589 		$result = $wpdb->update( $wpdb->posts, $update, array( 'ID' => $this_revision->ID ) );
       
   590 
       
   591 		if ( $result )
       
   592 			wp_cache_delete( $this_revision->ID, 'posts' );
       
   593 
       
   594 	} while ( $prev_revision );
       
   595 
       
   596 	delete_option( $lock );
       
   597 
       
   598 	// Add a copy of the post as latest revision.
       
   599 	if ( $add_last )
       
   600 		wp_save_post_revision( $post->ID );
       
   601 
       
   602 	return true;
       
   603 }