ches all
 * children for the same to retrieve all children of a page. Does not make any
 * SQL queries to get the children.
 *
 * @since 1.5.1
 *
 * @param int $page_id Page ID.
 * @param array $pages List of pages' objects.
 * @return array
 */
function get_page_children($page_id, $pages) {
	$page_list = array();
	foreach ( (array) $pages as $page ) {
		if ( $page->post_parent == $page_id ) {
			$page_list[] = $page;
			if ( $children = get_page_children($page->ID, $pages) )
				$page_list = array_merge($page_list, $children);
		}
	}
	return $page_list;
}

/**
 * Order the pages with children under parents in a flat list.
 *
 * It uses auxiliary structure to hold parent-children relationships and
 * runs in O(N) complexity
 *
 * @since 2.0.0
 *
 * @param array $pages Posts array.
 * @param int $page_id Parent page ID.
 * @return array A list arranged by hierarchy. Children immediately follow their parents.
 */
function get_page_hierarchy( &$pages, $page_id = 0 ) {
	if ( empty( $pages ) ) {
		$result = array();
		return $result;
	}

	$children = array();
	foreach ( (array) $pages as $p ) {
		$parent_id = intval( $p->post_parent );
		$children[ $parent_id ][] = $p;
	}

	$result = array();
	_page_traverse_name( $page_id, $children, $result );

	return $result;
}

/**
 * function to traverse and return all the nested children post names of a root page.
 * $children contains parent-children relations
 *
 * @since 2.9.0
 */
function _page_traverse_name( $page_id, &$children, &$result ){
	if ( isset( $children[ $page_id ] ) ){
		foreach( (array)$children[ $page_id ] as $child ) {
			$result[ $child->ID ] = $child->post_name;
			_page_traverse_name( $child->ID, $children, $result );
		}
	}
}

/**
 * Builds URI for a page.
 *
 * Sub pages will be in the "directory" under the parent page post name.
 *
 * @since 1.5.0
 *
 * @param mixed $page Page object or page ID.
 * @return string Page URI.
 */
function get_page_uri($page) {
	$page = get_post( $page );

	$uri = $page->post_name;

	foreach ( $page->ancestors as $parent ) {
		$uri = get_post( $parent )->post_name . "/" . $uri;
	}

	return $uri;
}

/**
 * Retrieve a list of pages.
 *
 * The defaults that can be overridden are the following: 'child_of',
 * 'sort_order', 'sort_column', 'post_title', 'hierarchical', 'exclude',
 * 'include', 'meta_key', 'meta_value','authors', 'number', and 'offset'.
 *
 * @since 1.5.0
 * @uses $wpdb
 *
 * @param mixed $args Optional. Array or string of options that overrides defaults.
 * @return array List of pages matching defaults or $args
 */
function get_pages($args = '') {
	global $wpdb;

	$pages = false;

	$defaults = array(
		'child_of' => 0, 'sort_order' => 'ASC',
		'sort_column' => 'post_title', 'hierarchical' => 1,
		'exclude' => array(), 'include' => array(),
		'meta_key' => '', 'meta_value' => '',
		'authors' => '', 'parent' => -1, 'exclude_tree' => '',
		'number' => '', 'offset' => 0,
		'post_type' => 'page', 'post_status' => 'publish',
	);

	$r = wp_parse_args( $args, $defaults );
	extract( $r, EXTR_SKIP );
	$number = (int) $number;
	$offset = (int) $offset;

	// Make sure the post type is hierarchical
	$hierarchical_post_types = get_post_types( array( 'hierarchical' => true ) );
	if ( !in_array( $post_type, $hierarchical_post_types ) )
		return $pages;

	// Make sure we have a valid post status
	if ( !is_array( $post_status ) )
		$post_status = explode( ',', $post_status );
	if ( array_diff( $post_status, get_post_stati() ) )
		return $pages;

	$cache = array();
	$key = md5( serialize( compact(array_keys($defaults)) ) );
	if ( $cache = wp_cache_get( 'get_pages', 'posts' ) ) {
		if ( is_array($cache) && isset( $cache[ $key ] ) && is_array( $cache[ $key ] ) ) {
			// Convert to WP_Post instances
			$pages = array_map( 'get_post', $cache[ $key ] );
			$pages = apply_filters( 'get_pages', $pages, $r );
			return $pages;
		}
	}

	if ( !is_array($cache) )
		$cache = array();

	$inclusions = '';
	if ( !empty($include) ) {
		$child_of = 0; //ignore child_of, parent, exclude, meta_key, and meta_value params if using include
		$parent = -1;
		$exclude = '';
		$meta_key = '';
		$meta_value = '';
		$hierarchical = false;
		$incpages = wp_parse_id_list( $include );
		if ( ! empty( $incpages ) ) {
			foreach ( $incpages as $incpage ) {
				if (empty($inclusions))
					$inclusions = $wpdb->prepare(' AND ( ID = %d ', $incpage);
				else
					$inclusions .= $wpdb->prepare(' OR ID = %d ', $incpage);
			}
		}
	}
	if (!empty($inclusions))
		$inclusions .= ')';

	$exclusions = '';
	if ( !empty($exclude) ) {
		$expages = wp_parse_id_list( $exclude );
		if ( ! empty( $expages ) ) {
			foreach ( $expages as $expage ) {
				if (empty($exclusions))
					$exclusions = $wpdb->prepare(' AND ( ID <> %d ', $expage);
				else
					$exclusions .= $wpdb->prepare(' AND ID <> %d ', $expage);
			}
		}
	}
	if (!empty($exclusions))
		$exclusions .= ')';

	$author_query = '';
	if (!empty($authors)) {
		$post_authors = preg_split('/[\s,]+/',$authors);

		if ( ! empty( $post_authors ) ) {
			foreach ( $post_authors as $post_author ) {
				//Do we have an author id or an author login?
				if ( 0 == intval($post_author) ) {
					$post_author = get_user_by('login', $post_author);
					if ( empty($post_author) )
						continue;
					if ( empty($post_author->ID) )
						continue;
					$post_author = $post_author->ID;
				}

				if ( '' == $author_query )
					$author_query = $wpdb->prepare(' post_author = %d ', $post_author);
				else
					$author_query .= $wpdb->prepare(' OR post_author = %d ', $post_author);
			}
			if ( '' != $author_query )
				$author_query = " AND ($author_query)";
		}
	}

	$join = '';
	$where = "$exclusions $inclusions ";
	if ( ! empty( $meta_key ) || ! empty( $meta_value ) ) {
		$join = " LEFT JOIN $wpdb->postmeta ON ( $wpdb->posts.ID = $wpdb->postmeta.post_id )";

		// meta_key and meta_value might be slashed
		$meta_key = stripslashes($meta_key);
		$meta_value = stripslashes($meta_value);
		if ( ! empty( $meta_key ) )
			$where .= $wpdb->prepare(" AND $wpdb->postmeta.meta_key = %s", $meta_key);
		if ( ! empty( $meta_value ) )
			$where .= $wpdb->prepare(" AND $wpdb->postmeta.meta_value = %s", $meta_value);

	}

	if ( $parent >= 0 )
		$where .= $wpdb->prepare(' AND post_parent = %d ', $parent);

	if ( 1 == count( $post_status ) ) {
		$where_post_type = $wpdb->prepare( "post_type = %s AND post_status = %s", $post_type, array_shift( $post_status ) );
	} else {
		$post_status = implode( "', '", $post_status );
		$where_post_type = $wpdb->prepare( "post_type = %s AND post_status IN ('$post_status')", $post_type );
	}

	$orderby_array = array();
	$allowed_keys = array('author', 'post_author', 'date', 'post_date', 'title', 'post_title', 'name', 'post_name', 'modified',
						  'post_modified', 'modified_gmt', 'post_modified_gmt', 'menu_order', 'parent', 'post_parent',
						  'ID', 'rand', 'comment_count');
	foreach ( explode( ',', $sort_column ) as $orderby ) {
		$orderby = trim( $orderby );
		if ( !in_array( $orderby, $allowed_keys ) )
			continue;

		switch ( $orderby ) {
			case 'menu_order':
				break;
			case 'ID':
				$orderby = "$wpdb->posts.ID";
				break;
			case 'rand':
				$orderby = 'RAND()';
				break;
			case 'comment_count':
				$orderby = "$wpdb->posts.comment_count";
				break;
			default:
				if ( 0 === strpos( $orderby, 'post_' ) )
					$orderby = "$wpdb->posts." . $orderby;
				else
					$orderby = "$wpdb->posts.post_" . $orderby;
		}

		$orderby_array[] = $orderby;

	}
	$sort_column = ! empty( $orderby_array ) ? implode( ',', $orderby_array ) : "$wpdb->posts.post_title";

	$sort_order = strtoupper( $sort_order );
	if ( '' !== $sort_order && !in_array( $sort_order, array( 'ASC', 'DESC' ) ) )
		$sort_order = 'ASC';

	$query = "SELECT * FROM $wpdb->posts $join WHERE ($where_post_type) $where ";
	$query .= $author_query;
	$query .= " ORDER BY " . $sort_column . " " . $sort_order ;

	if ( !empty($number) )
		$query .= ' LIMIT ' . $offset . ',' . $number;

	$pages = $wpdb->get_results($query);

	if ( empty($pages) ) {
		$pages = apply_filters('get_pages', array(), $r);
		return $pages;
	}

	// Sanitize before caching so it'll only get done once
	$num_pages = count($pages);
	for ($i = 0; $i < $num_pages; $i++) {
		$pages[$i] = sanitize_post($pages[$i], 'raw');
	}

	// Update cache.
	update_post_cache( $pages );

	if ( $child_of || $hierarchical )
		$pages = get_page_children($child_of, $pages);

	if ( !empty($exclude_tree) ) {
		$exclude = (int) $exclude_tree;
		$children = get_page_children($exclude, $pages);
		$excludes = array();
		foreach ( $children as $child )
			$excludes[] = $child->ID;
		$excludes[] = $exclude;
		$num_pages = count($pages);
		for ( $i = 0; $i < $num_pages; $i++ ) {
			if ( in_array($pages[$i]->ID, $excludes) )
				unset($pages[$i]);
		}
	}

	$cache[ $key ] = $pages;
	wp_cache_set( 'get_pages', $cache, 'posts' );

	// Convert to WP_Post instances
	$pages = array_map( 'get_post', $pages );

	$pages = apply_filters('get_pages', $pages, $r);

	return $pages;
}

//
// Attachment functions
//

/**
 * Check if the attachment URI is local one and is really an attachment.
 *
 * @since 2.0.0
 *
 * @param string $url URL to check
 * @return bool True on success, false on failure.
 */
function is_local_attachment($url) {
	if (strpos($url, home_url()) === false)
		return false;
	if (strpos($url, home_url('/?attachment_id=')) !== false)
		return true;
	if ( $id = url_to_postid($url) ) {
		$post = get_post($id);
		if ( 'attachment' == $post->post_type )
			return true;
	}
	return false;
}

/**
 * Insert an attachment.
 *
 * If you set the 'ID' in the $object parameter, it will mean that you are
 * updating and attempt to update the attachment. You can also set the
 * attachment name or title by setting the key 'post_name' or 'post_title'.
 *
 * You can set the dates for the attachment manually by setting the 'post_date'
 * and 'post_date_gmt' keys' values.
 *
 * By default, the comments will use the default settings for whether the
 * comments are allowed. You can close them manually or keep them open by
 * setting the value for the 'comment_status' key.
 *
 * The $object parameter can have the following:
 *     'post_status'   - Default is 'draft'. Can not be overridden, set the same as parent post.
 *     'post_type'     - Default is 'post', will be set to attachment. Can not override.
 *     'post_author'   - Default is current user ID. The ID of the user, who added the attachment.
 *     'ping_status'   - Default is the value in default ping status option. Whether the attachment
 *                       can accept pings.
 *     'post_parent'   - Default is 0. Can use $parent parameter or set this for the post it belongs
 *                       to, if any.
 *     'menu_order'    - Default is 0. The order it is displayed.
 *     'to_ping'       - Whether to ping.
 *     'pinged'        - Default is empty string.
 *     'post_password' - Default is empty string. The password to access the attachment.
 *     'guid'          - Global Unique ID for referencing the attachment.
 *     'post_content_filtered' - Attachment post content filtered.
 *     'post_excerpt'  - Attachment excerpt.
 *
 * @since 2.0.0
 * @uses $wpdb
 * @uses $user_ID
 * @uses do_action() Calls 'edit_attachment' on $post_ID if this is an update.
 * @uses do_action() Calls 'add_attachment' on $post_ID if this is not an update.
 *
 * @param string|array $object Arguments to override defaults.
 * @param string $file Optional filename.
 * @param int $parent Parent post ID.
 * @return int Attachment ID.
 */
function wp_insert_attachment($object, $file = false, $parent = 0) {
	global $wpdb, $user_ID;

	$defaults = array('post_status' => 'inherit', 'post_type' => 'post', 'post_author' => $user_ID,
		'ping_status' => get_option('default_ping_status'), 'post_parent' => 0,
		'menu_order' => 0, 'to_ping' =>  '', 'pinged' => '', 'post_password' => '',
		'guid' => '', 'post_content_filtered' => '', 'post_excerpt' => '', 'import_id' => 0, 'context' => '');

	$object = wp_parse_args($object, $defaults);
	if ( !empty($parent) )
		$object['post_parent'] = $parent;

	unset( $object[ 'filter' ] );

	$object = sanitize_post($object, 'db');

	// export array as variables
	extract($object, EXTR_SKIP);

	if ( empty($post_author) )
		$post_author = $user_ID;

	$post_type = 'attachment';

	if ( ! in_array( $post_status, array( 'inherit', 'private' ) ) )
		$post_status = 'inherit';

	if ( !empty($post_category) )
		$post_category = array_filter($post_category); // Filter out empty terms

	// Make sure we set a valid category.
	if ( empty($post_category) || 0 == count($post_category) || !is_array($post_category) ) {
		$post_category = array();
	}

	// Are we updating or creating?
	if ( !empty($ID) ) {
		$update = true;
		$post_ID = (int) $ID;
	} else {
		$update = false;
		$post_ID = 0;
	}

	// Create a valid post name.
	if ( empty($post_name) )
		$post_name = sanitize_title($post_title);
	else
		$post_name = sanitize_title($post_name);

	// expected_slashed ($post_name)
	$post_name = wp_unique_post_slug($post_name, $post_ID, $post_status, $post_type, $post_parent);

	if ( empty($post_date) )
		$post_date = current_time('mysql');
	if ( empty($post_date_gmt) )
		$post_date_gmt = current_time('mysql', 1);

	if ( empty($post_modified) )
		$post_modified = $post_date;
	if ( empty($post_modified_gmt) )
		$post_modified_gmt = $post_date_gmt;

	if ( empty($comment_status) ) {
		if ( $update )
			$comment_status = 'closed';
		else
			$comment_status = get_option('default_comment_status');
	}
	if ( empty($ping_status) )
		$ping_status = get_option('default_ping_status');

	if ( isset($to_ping) )
		$to_ping = preg_replace('|\s+|', "\n", $to_ping);
	else
		$to_ping = '';

	if ( isset($post_parent) )
		$post_parent = (int) $post_parent;
	else
		$post_parent = 0;

	if ( isset($menu_order) )
		$menu_order = (int) $menu_order;
	else
		$menu_order = 0;

	if ( !isset($post_password) )
		$post_password = '';

	if ( ! isset($pinged) )
		$pinged = '';

	// expected_slashed (everything!)
	$data = compact( array( 'post_author', 'post_date', 'post_date_gmt', 'post_content', 'post_content_filtered', 'post_title', 'post_excerpt', 'post_status', 'post_type', 'comment_status', 'ping_status', 'post_password', 'post_name', 'to_ping', 'pinged', 'post_modified', 'post_modified_gmt', 'post_parent', 'menu_order', 'post_mime_type', 'guid' ) );
	$data = stripslashes_deep( $data );

	if ( $update ) {
		$wpdb->update( $wpdb->posts, $data, array( 'ID' => $post_ID ) );
	} else {
		// If there is a suggested ID, use it if not already present
		if ( !empty($import_id) ) {
			$import_id = (int) $import_id;
			if ( ! $wpdb->get_var( $wpdb->prepare("SELECT ID FROM $wpdb->posts WHERE ID = %d", $import_id) ) ) {
				$data['ID'] = $import_id;
			}
		}

		$wpdb->insert( $wpdb->posts, $data );
		$post_ID = (int) $wpdb->insert_id;
	}

	if ( empty($post_name) ) {
		$post_name = sanitize_title($post_title, $post_ID);
		$wpdb->update( $wpdb->posts, compact("post_name"), array( 'ID' => $post_ID ) );
	}

	if ( is_object_in_taxonomy($post_type, 'category') )
		wp_set_post_categories( $post_ID, $post_category );

	if ( isset( $tags_input ) && is_object_in_taxonomy($post_type, 'post_tag') )
		wp_set_post_tags( $post_ID, $tags_input );

	// support for all custom taxonomies
	if ( !empty($tax_input) ) {
		foreach ( $tax_input as $taxonomy => $tags ) {
			$taxonomy_obj = get_taxonomy($taxonomy);
			if ( is_array($tags) ) // array = hierarchical, string = non-hierarchical.
				$tags = array_filter($tags);
			if ( current_user_can($taxonomy_obj->cap->assign_terms) )
				wp_set_post_terms( $post_ID, $tags, $taxonomy );
		}
	}

	if ( $file )
		update_attached_file( $post_ID, $file );

	clean_post_cache( $post_ID );

	if ( ! empty( $context ) )
		add_post_meta( $post_ID, '_wp_attachment_context', $context, true );

	if ( $update) {
		do_action('edit_attachment', $post_ID);
	} else {
		do_action('add_attachment', $post_ID);
	}

	return $post_ID;
}

/**
 * Trashes or deletes an attachment.
 *
 * When an attachment is permanently deleted, the file will also be removed.
 * Deletion removes all post meta fields, taxonomy, comments, etc. associated
 * with the attachment (except the main post).
 *
 * The attachment is moved to the trash instead of permanently deleted unless trash
 * for media is disabled, item is already in the trash, or $force_delete is true.
 *
 * @since 2.0.0
 * @uses $wpdb
 * @uses do_action() Calls 'delete_attachment' hook on Attachment ID.
 *
 * @param int $post_id Attachment ID.
 * @param bool $force_delete Whether to bypass trash and force deletion. Defaults to false.
 * @return mixed False on failure. Post data on success.
 */
function wp_delete_attachment( $post_id, $force_delete = false ) {
	global $wpdb;

	if ( !$post = $wpdb->get_row( $wpdb->prepare("SELECT * FROM $wpdb->posts WHERE ID = %d", $post_id) ) )
		return $post;

	if ( 'attachment' != $post->post_type )
		return false;

	if ( !$force_delete && EMPTY_TRASH_DAYS && MEDIA_TRASH && 'trash' != $post->post_status )
		return wp_trash_post( $post_id );

	delete_post_meta($post_id, '_wp_trash_meta_status');
	delete_post_meta($post_id, '_wp_trash_meta_time');

	$meta = wp_get_attachment_metadata( $post_id );
	$backup_sizes = get_post_meta( $post->ID, '_wp_attachment_backup_sizes', true );
	$file = get_attached_file( $post_id );

	$intermediate_sizes = array();
	foreach ( get_intermediate_image_sizes() as $size ) {
		if ( $intermediate = image_get_intermediate_size( $post_id, $size ) )
			$intermediate_sizes[] = $intermediate;
	}

	if ( is_multisite() )
		delete_transient( 'dirsize_cache' );

	do_action('delete_attachment', $post_id);

	wp_delete_object_term_relationships($post_id, array('category', 'post_tag'));
	wp_delete_object_term_relationships($post_id, get_object_taxonomies($post->post_type));

	delete_metadata( 'post', null, '_thumbnail_id', $post_id, true ); // delete all for any posts.

	$comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d", $post_id ));
	foreach ( $comment_ids as $comment_id )
		wp_delete_comment( $comment_id, true );

	$post_meta_ids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE post_id = %d ", $post_id ));
	foreach ( $post_meta_ids as $mid )
		delete_metadata_by_mid( 'post', $mid );

	do_action( 'delete_post', $post_id );
	$wpdb->delete( $wpdb->posts, array( 'ID' => $post_id ) );
	do_action( 'deleted_post', $post_id );

	$uploadpath = wp_upload_dir();

	if ( ! empty($meta['thumb']) ) {
		// Don't delete the thumb if another attachment uses it
		if (! $wpdb->get_row( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attachment_metadata' AND meta_value LIKE %s AND post_id <> %d", '%' . $meta['thumb'] . '%', $post_id)) ) {
			$thumbfile = str_replace(basename($file), $meta['thumb'], $file);
			$thumbfile = apply_filters('wp_delete_file', $thumbfile);
			@ unlink( path_join($uploadpath['basedir'], $thumbfile) );
		}
	}

	// remove intermediate and backup images if there are any
	foreach ( $intermediate_sizes as $intermediate ) {
		$intermediate_file = apply_filters( 'wp_delete_file', $intermediate['path'] );
		@ unlink( path_join($uploadpath['basedir'], $intermediate_file) );
	}

	if ( is_array($backup_sizes) ) {
		foreach ( $backup_sizes as $size ) {
			$del_file = path_join( dirname($meta['file']), $size['file'] );
			$del_file = apply_filters('wp_delete_file', $del_file);
			@ unlink( path_join($uploadpath['basedir'], $del_file) );
		}
	}

	$file = apply_filters('wp_delete_file', $file);

	if ( ! empty($file) )
		@ unlink($file);

	clean_post_cache( $post );

	return $post;
}

/**
 * Retrieve attachment meta field for attachment ID.
 *
 * @since 2.1.0
 *
 * @param int $post_id Attachment ID
 * @param bool $unfiltered Optional, default is false. If true, filters are not run.
 * @return string|bool Attachment meta field. False on failure.
 */
function wp_get_attachment_metadata( $post_id = 0, $unfiltered = false ) {
	$post_id = (int) $post_id;
	if ( !$post = get_post( $post_id ) )
		return false;

	$data = get_post_meta( $post->ID, '_wp_attachment_metadata', true );

	if ( $unfiltered )
		return $data;

	return apply_filters( 'wp_get_attachment_metadata', $data, $post->ID );
}

/**
 * Update metadata for an attachment.
 *
 * @since 2.1.0
 *
 * @param int $post_id Attachment ID.
 * @param array $data Attachment data.
 * @return int
 */
function wp_update_attachment_metadata( $post_id, $data ) {
	$post_id = (int) $post_id;
	if ( !$post = get_post( $post_id ) )
		return false;

	if ( $data = apply_filters( 'wp_update_attachment_metadata', $data, $post->ID ) )
		return update_post_meta( $post->ID, '_wp_attachment_metadata', $data );
	else
		return delete_post_meta( $post->ID, '_wp_attachment_metadata' );
}

/**
 * Retrieve the URL for an attachment.
 *
 * @since 2.1.0
 *
 * @param int $post_id Attachment ID.
 * @return string
 */
function wp_get_attachment_url( $post_id = 0 ) {
	$post_id = (int) $post_id;
	if ( !$post = get_post( $post_id ) )
		return false;

	if ( 'attachment' != $post->post_type )
		return false;

	$url = '';
	if ( $file = get_post_meta( $post->ID, '_wp_attached_file', true) ) { //Get attached file
		if ( ($uploads = wp_upload_dir()) && false === $uploads['error'] ) { //Get upload directory
			if ( 0 === strpos($file, $uploads['basedir']) ) //Check that the upload base exists in the file location
				$url = str_replace($uploads['basedir'], $uploads['baseurl'], $file); //replace file location with url location
			elseif ( false !== strpos($file, 'wp-content/uploads') )
				$url = $uploads['baseurl'] . substr( $file, strpos($file, 'wp-content/uploads') + 18 );
			else
				$url = $uploads['baseurl'] . "/$file"; //Its a newly uploaded file, therefor $file is relative to the basedir.
		}
	}

	if ( empty($url) ) //If any of the above options failed, Fallback on the GUID as used pre-2.7, not recommended to rely upon this.
		$url = get_the_guid( $post->ID );

	$url = apply_filters( 'wp_get_attachment_url', $url, $post->ID );

	if ( empty( $url ) )
		return false;

	return $url;
}

/**
 * Retrieve thumbnail for an attachment.
 *
 * @since 2.1.0
 *
 * @param int $post_id Attachment ID.
 * @return mixed False on failure. Thumbnail file path on success.
 */
function wp_get_attachment_thumb_file( $post_id = 0 ) {
	$post_id = (int) $post_id;
	if ( !$post = get_post( $post_id ) )
		return false;
	if ( !is_array( $imagedata = wp_get_attachment_metadata( $post->ID ) ) )
		return false;

	$file = get_attached_file( $post->ID );

	if ( !empty($imagedata['thumb']) && ($thumbfile = str_replace(basename($file), $imagedata['thumb'], $file)) && file_exists($thumbfile) )
		return apply_filters( 'wp_get_attachment_thumb_file', $thumbfile, $post->ID );
	return false;
}

/**
 * Retrieve URL for an attachment thumbnail.
 *
 * @since 2.1.0
 *
 * @param int $post_id Attachment ID
 * @return string|bool False on failure. Thumbnail URL on success.
 */
function wp_get_attachment_thumb_url( $post_id = 0 ) {
	$post_id = (int) $post_id;
	if ( !$post = get_post( $post_id ) )
		return false;
	if ( !$url = wp_get_attachment_url( $post->ID ) )
		return false;

	$sized = image_downsize( $post_id, 'thumbnail' );
	if ( $sized )
		return $sized[0];

	if ( !$thumb = wp_get_attachment_thumb_file( $post->ID ) )
		return false;

	$url = str_replace(basename($url), basename($thumb), $url);

	return apply_filters( 'wp_get_attachment_thumb_url', $url, $post->ID );
}

/**
 * Check if the attachment is an image.
 *
 * @since 2.1.0
 *
 * @param int $post_id Attachment ID
 * @return bool
 */
function wp_attachment_is_image( $post_id = 0 ) {
	$post_id = (int) $post_id;
	if ( !$post = get_post( $post_id ) )
		return false;

	if ( !$file = get_attached_file( $post->ID ) )
		return false;

	$ext = preg_match('/\.([^.]+)$/', $file, $matches) ? strtolower($matches[1]) : false;

	$image_exts = array( 'jpg', 'jpeg', 'jpe', 'gif', 'png' );

	if ( 'image/' == substr($post->post_mime_type, 0, 6) || $ext && 'import' == $post->post_mime_type && in_array($ext, $image_exts) )
		return true;
	return false;
}

/**
 * Retrieve the icon for a MIME type.
 *
 * @since 2.1.0
 *
 * @param string|int $mime MIME type or attachment ID.
 * @return string|bool
 */
function wp_mime_type_icon( $mime = 0 ) {
	if ( !is_numeric($mime) )
		$icon = wp_cache_get("mime_type_icon_$mime");

	$post_id = 0;
	if ( empty($icon) ) {
		$post_mimes = array();
		if ( is_numeric($mime) ) {
			$mime = (int) $mime;
			if ( $post = get_post( $mime ) ) {
				$post_id = (int) $post->ID;
				$ext = preg_replace('/^.+?\.([^.]+)$/', '$1', $post->guid);
				if ( !empty($ext) ) {
					$post_mimes[] = $ext;
					if ( $ext_type = wp_ext2type( $ext ) )
						$post_mimes[] = $ext_type;
				}
				$mime = $post->post_mime_type;
			} else {
				$mime = 0;
			}
		} else {
			$post_mimes[] = $mime;
		}

		$icon_files = wp_cache_get('icon_files');

		if ( !is_array($icon_files) ) {
			$icon_dir = apply_filters( 'icon_dir', ABSPATH . WPINC . '/images/crystal' );
			$icon_dir_uri = apply_filters( 'icon_dir_uri', includes_url('images/crystal') );
			$dirs = apply_filters( 'icon_dirs', array($icon_dir => $icon_dir_uri) );
			$icon_files = array();
			while ( $dirs ) {
				$keys = array_keys( $dirs );
				$dir = array_shift( $keys );
				$uri = array_shift($dirs);
				if ( $dh = opendir($dir) ) {
					while ( false !== $file = readdir($dh) ) {
						$file = basename($file);
						if ( substr($file, 0, 1) == '.' )
							continue;
						if ( !in_array(strtolower(substr($file, -4)), array('.png', '.gif', '.jpg') ) ) {
							if ( is_dir("$dir/$file") )
								$dirs["$dir/$file"] = "$uri/$file";
							continue;
						}
						$icon_files["$dir/$file"] = "$uri/$file";
					}
					closedir($dh);
				}
			}
			wp_cache_add( 'icon_files', $icon_files, 'default', 600 );
		}

		// Icon basename - extension = MIME wildcard
		foreach ( $icon_files as $file => $uri )
			$types[ preg_replace('/^([^.]*).*$/', '$1', basename($file)) ] =& $icon_files[$file];

		if ( ! empty($mime) ) {
			$post_mimes[] = substr($mime, 0, strpos($mime, '/'));
			$post_mimes[] = substr($mime, strpos($mime, '/') + 1);
			$post_mimes[] = str_replace('/', '_', $mime);
		}

		$matches = wp_match_mime_types(array_keys($types), $post_mimes);
		$matches['default'] = array('default');

		foreach ( $matches as $match => $wilds ) {
			if ( isset($types[$wilds[0]])) {
				$icon = $types[$wilds[0]];
				if ( !is_numeric($mime) )
					wp_cache_add("mime_type_icon_$mime", $icon);
				break;
			}
		}
	}

	return apply_filters( 'wp_mime_type_icon', $icon, $mime, $post_id ); // Last arg is 0 if function pass mime type.
}

/**
 * Checked for changed slugs for published post objects and save the old slug.
 *
 * The function is used when a post object of any type is updated,
 * by comparing the current and previous post objects.
 *
 * If the slug was changed and not already part of the old slugs then it will be
 * added to the post meta field ('_wp_old_slug') for storing old slugs for that
 * post.
 *
 * The most logically usage of this function is redirecting changed post objects, so
 * that those that linked to an changed post will be redirected to the new post.
 *
 * @since 2.1.0
 *
 * @param int $post_id Post ID.
 * @param object $post The Post Object
 * @param object $post_before The Previous Post Object
 * @return int Same as $post_id
 */
function wp_check_for_changed_slugs($post_id, $post, $post_before) {
	// dont bother if it hasnt changed
	if ( $post->post_name == $post_before->post_name )
		return;

	// we're only concerned with published, non-hierarchical objects
	if ( $post->post_status != 'publish' || is_post_type_hierarchical( $post->post_type ) )
		return;

	$old_slugs = (array) get_post_meta($post_id, '_wp_old_slug');

	// if we haven't added this old slug before, add it now
	if ( !empty( $post_before->post_name ) && !in_array($post_before->post_name, $old_slugs) )
		add_post_meta($post_id, '_wp_old_slug', $post_before->post_name);

	// if the new slug was used previously, delete it from the list
	if ( in_array($post->post_name, $old_slugs) )
		delete_post_meta($post_id, '_wp_old_slug', $post->post_name);
}

/**
 * Retrieve the private post SQL based on capability.
 *
 * This function provides a standardized way to appropriately select on the
 * post_status of a post type. The function will return a piece of SQL code
 * that can be added to a WHERE clause; this SQL is constructed to allow all
 * published posts, and all private posts to which the user has access.
 *
 * @since 2.2.0
 *
 * @uses $user_ID
 *
 * @param string $post_type currently only supports 'post' or 'page'.
 * @return string SQL code that can be added to a where clause.
 */
function get_private_posts_cap_sql( $post_type ) {
	return get_posts_by_author_sql( $post_type, false );
}

/**
 * Retrieve the post SQL based on capability, author, and type.
 *
 * @see get_private_posts_cap_sql() for full description.
 *
 * @since 3.0.0
 * @param string $post_type Post type.
 * @param bool $full Optional. Returns a full WHERE statement instead of just an 'andalso' term.
 * @param int $post_author Optional. Query posts having a single author ID.
 * @param bool $public_only Optional. Only return public posts. Skips cap checks for $current_user.  Default is false.
 * @return string SQL WHERE code that can be added to a query.
 */
function get_posts_by_author_sql( $post_type, $full = true, $post_author = null, $public_only = false ) {
	global $user_ID, $wpdb;

	// Private posts
	$post_type_obj = get_post_type_object( $post_type );
	if ( ! $post_type_obj )
		return $full ? 'WHERE 1 = 0' : ' 1 = 0 ';

	// This hook is deprecated. Why you'd want to use it, I dunno.
	if ( ! $cap = apply_filters( 'pub_priv_sql_capability', '' ) )
		$cap = $post_type_obj->cap->read_private_posts;

	if ( $full ) {
		if ( null === $post_author ) {
			$sql = $wpdb->prepare( 'WHERE post_type = %s AND ', $post_type );
		} else {
			$sql = $wpdb->prepare( 'WHERE post_author = %d AND post_type = %s AND ', $post_author, $post_type );
		}
	} else {
		$sql = '';
	}

	$sql .= "(post_status = 'publish'";

	// Only need to check the cap if $public_only is false
	if ( false === $public_only ) {
		if ( current_user_can( $cap ) ) {
			// Does the user have the capability to view private posts? Guess so.
			$sql .= " OR post_status = 'private'";
		} elseif ( is_user_logged_in() ) {
			// Users can view their own private posts.
			$id = (int) $user_ID;
			if ( null === $post_author || ! $full ) {
				$sql .= " OR post_status = 'private' AND post_author = $id";
			} elseif ( $id == (int) $post_author ) {
				$sql .= " OR post_status = 'private'";
			} // else none
		} // else none
	}

	$sql .= ')';

	return $sql;
}

/**
 * Retrieve the date that the last post was published.
 *
 * The server timezone is the default and is the difference between GMT and
 * server time. The 'blog' value is the date when the last post was posted. The
 * 'gmt' is when the last post was posted in GMT formatted date.
 *
 * @since 0.71
 *
 * @uses apply_filters() Calls 'get_lastpostdate' filter
 *
 * @param string $timezone The location to get the time. Can be 'gmt', 'blog', or 'server'.
 * @return string The date of the last post.
 */
function get_lastpostdate($timezone = 'server') {
	return apply_filters( 'get_lastpostdate', _get_last_post_time( $timezone, 'date' ), $timezone );
}

/**
 * Retrieve last post modified date depending on timezone.
 *
 * The server timezone is the default and is the difference between GMT and
 * server time. The 'blog' value is just when the last post was modified. The
 * 'gmt' is when the last post was modified in GMT time.
 *
 * @since 1.2.0
 * @uses apply_filters() Calls 'get_lastpostmodified' filter
 *
 * @param string $timezone The location to get the time. Can be 'gmt', 'blog', or 'server'.
 * @return string The date the post was last modified.
 */
function get_lastpostmodified($timezone = 'server') {
	$lastpostmodified = _get_last_post_time( $timezone, 'modified' );

	$lastpostdate = get_lastpostdate($timezone);
	if ( $lastpostdate > $lastpostmodified )
		$lastpostmodified = $lastpostdate;

	return apply_filters( 'get_lastpostmodified', $lastpostmodified, $timezone );
}

/**
 * Retrieve latest post date data based on timezone.
 *
 * @access private
 * @since 3.1.0
 *
 * @param string $timezone The location to get the time. Can be 'gmt', 'blog', or 'server'.
 * @param string $field Field to check. Can be 'date' or 'modified'.
 * @return string The date.
 */
function _get_last_post_time( $timezone, $field ) {
	global $wpdb;

	if ( !in_array( $field, array( 'date', 'modified' ) ) )
		return false;

	$timezone = strtolower( $timezone );

	$key = "lastpost{$field}:$timezone";

	$date = wp_cache_get( $key, 'timeinfo' );

	if ( !$date ) {
		$add_seconds_server = date('Z');

		$post_types = get_post_types( array( 'public' => true ) );
		array_walk( $post_types, array( &$wpdb, 'escape_by_ref' ) );
		$post_types = "'" . implode( "', '", $post_types ) . "'";

		switch ( $timezone ) {
			case 'gmt':
				$date = $wpdb->get_var("SELECT post_{$field}_gmt FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
				break;
			case 'blog':
				$date = $wpdb->get_var("SELECT post_{$field} FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
				break;
			case 'server':
				$date = $wpdb->get_var("SELECT DATE_ADD(post_{$field}_gmt, INTERVAL '$add_seconds_server' SECOND) FROM $wpdb->posts WHERE post_status = 'publish' AND post_type IN ({$post_types}) ORDER BY post_{$field}_gmt DESC LIMIT 1");
				break;
		}

		if ( $date )
			wp_cache_set( $key, $date, 'timeinfo' );
	}

	return $date;
}

/**
 * Updates posts in cache.
 *
 * @package WordPress
 * @subpackage Cache
 * @since 1.5.1
 *
 * @param array $posts Array of post objects
 */
function update_post_cache( &$posts ) {
	if ( ! $posts )
		return;

	foreach ( $posts as $post )
		wp_cache_add( $post->ID, $post, 'posts' );
}

/**
 * Will clean the post in the cache.
 *
 * Cleaning means delete from the cache of the post. Will call to clean the term
 * object cache associated with the post ID.
 *
 * This function not run if $_wp_suspend_cache_invalidation is not empty. See
 * wp_suspend_cache_invalidation().
 *
 * @package WordPress
 * @subpackage Cache
 * @since 2.0.0
 *
 * @uses do_action() Calls 'clean_post_cache' on $id before adding children (if any).
 *
 * @param object|int $post The post object or ID to remove from the cache
 */
function clean_post_cache( $post ) {
	global $_wp_suspend_cache_invalidation, $wpdb;

	if ( ! empty( $_wp_suspend_cache_invalidation ) )
		return;

	$post = get_post( $post );
	if ( empty( $post ) )
		return;

	wp_cache_delete( $post->ID, 'posts' );
	wp_cache_delete( $post->ID, 'post_meta' );

	clean_object_term_cache( $post->ID, $post->post_type );

	wp_cache_delete( 'wp_get_archives', 'general' );

	do_action( 'clean_post_cache', $post->ID, $post );

	if ( is_post_type_hierarchical( $post->post_type ) )
		wp_cache_delete( 'get_pages', 'posts' );

	if ( 'page' == $post->post_type ) {
		wp_cache_delete( 'all_page_ids', 'posts' );
		do_action( 'clean_page_cache', $post->ID );
	}
}

/**
 * Call major cache updating functions for list of Post objects.
 *
 * @package WordPress
 * @subpackage Cache
 * @since 1.5.0
 *
 * @uses $wpdb
 * @uses update_post_cache()
 * @uses update_object_term_cache()
 * @uses update_postmeta_cache()
 *
 * @param array $posts Array of Post objects
 * @param string $post_type The post type of the posts in $posts. Default is 'post'.
 * @param bool $update_term_cache Whether to update the term cache. Default is true.
 * @param bool $update_meta_cache Whether to update the meta cache. Default is true.
 */
function update_post_caches(&$posts, $post_type = 'post', $update_term_cache = true, $update_meta_cache = true) {
	// No point in doing all this work if we didn't match any posts.
	if ( !$posts )
		return;

	update_post_cache($posts);

	$post_ids = array();
	foreach ( $posts as $post )
		$post_ids[] = $post->ID;

	if ( ! $post_type )
		$post_type = 'any';

	if ( $update_term_cache ) {
		if ( is_array($post_type) ) {
			$ptypes = $post_type;
		} elseif ( 'any' == $post_type ) {
			// Just use the post_types in the supplied posts.
			foreach ( $posts as $post )
				$ptypes[] = $post->post_type;
			$ptypes = array_unique($ptypes);
		} else {
			$ptypes = array($post_type);
		}

		if ( ! empty($ptypes) )
			update_object_term_cache($post_ids, $ptypes);
	}

	if ( $update_meta_cache )
		update_postmeta_cache($post_ids);
}

/**
 * Updates metadata cache for list of post IDs.
 *
 * Performs SQL query to retrieve the metadata for the post IDs and updates the
 * metadata cache for the posts. Therefore, the functions, which call this
 * function, do not need to perform SQL queries on their own.
 *
 * @package WordPress
 * @subpackage Cache
 * @since 2.1.0
 *
 * @uses $wpdb
 *
 * @param array $post_ids List of post IDs.
 * @return bool|array Returns false if there is nothing to update or an array of metadata.
 */
function update_postmeta_cache($post_ids) {
	return update_meta_cache('post', $post_ids);
}

/**
 * Will clean the attachment in the cache.
 *
 * Cleaning means delete from the cache. Optionally will clean the term
 * object cache associated with the attachment ID.
 *
 * This function will not run if $_wp_suspend_cache_invalidation is not empty. See
 * wp_suspend_cache_invalidation().
 *
 * @package WordPress
 * @subpackage Cache
 * @since 3.0.0
 *
 * @uses do_action() Calls 'clean_attachment_cache' on $id.
 *
 * @param int $id The attachment ID in the cache to clean
 * @param bool $clean_terms optional. Whether to clean terms cache
 */
function clean_attachment_cache($id, $clean_terms = false) {
	global $_wp_suspend_cache_invalidation;

	if ( !empty($_wp_suspend_cache_invalidation) )
		return;

	$id = (int) $id;

	wp_cache_delete($id, 'posts');
	wp_cache_delete($id, 'post_meta');

	if ( $clean_terms )
		clean_object_term_cache($id, 'attachment');

	do_action('clean_attachment_cache', $id);
}

//
// Hooks
//

/**
 * Hook for managing future post transitions to published.
 *
 * @since 2.3.0
 * @access private
 * @uses $wpdb
 * @uses do_action() Calls 'private_to_published' on post ID if this is a 'private_to_published' call.
 * @uses wp_clear_scheduled_hook() with 'publish_future_post' and post ID.
 *
 * @param string $new_status New post status
 * @param string $old_status Previous post status
 * @param object $post Object type containing the post information
 */
function _transition_post_status($new_status, $old_status, $post) {
	global $wpdb;

	if ( $old_status != 'publish' && $new_status == 'publish' ) {
		// Reset GUID if transitioning to publish and it is empty
		if ( '' == get_the_guid($post->ID) )
			$wpdb->update( $wpdb->posts, array( 'guid' => get_permalink( $post->ID ) ), array( 'ID' => $post->ID ) );
		do_action('private_to_published', $post->ID);  // Deprecated, use private_to_publish
	}

	// If published posts changed clear the lastpostmodified cache
	if ( 'publish' == $new_status || 'publish' == $old_status) {
		foreach ( array( 'server', 'gmt', 'blog' ) as $timezone ) {
			wp_cache_delete( "lastpostmodified:$timezone", 'timeinfo' );
			wp_cache_delete( "lastpostdate:$timezone", 'timeinfo' );
		}
	}

	// Always clears the hook in case the post status bounced from future to draft.
	wp_clear_scheduled_hook('publish_future_post', array( $post->ID ) );
}

/**
 * Hook used to schedule publication for a post marked for the future.
 *
 * The $post properties used and must exist are 'ID' and 'post_date_gmt'.
 *
 * @since 2.3.0
 * @access private
 *
 * @param int $deprecated Not used. Can be set to null. Never implemented.
 *   Not marked as deprecated with _deprecated_argument() as it conflicts with
 *   wp_transition_post_status() and the default filter for _future_post_hook().
 * @param object $post Object type containing the post information
 */
function _future_post_hook( $deprecated = '', $post ) {
	wp_clear_scheduled_hook( 'publish_future_post', array( $post->ID ) );
	wp_schedule_single_event( strtotime( get_gmt_from_date( $post->post_date ) . ' GMT') , 'publish_future_post', array( $post->ID ) );
}

/**
 * Hook to schedule pings and enclosures when a post is published.
 *
 * @since 2.3.0
 * @access private
 * @uses $wpdb
 * @uses XMLRPC_REQUEST constant.
 * @uses do_action() Calls 'xmlprc_publish_post' on post ID if XMLRPC_REQUEST is defined.
 *
 * @param int $post_id The ID in the database table of the post being published
 */
function _publish_post_hook($post_id) {
	global $wpdb;

	if ( defined('XMLRPC_REQUEST') )
		do_action('xmlrpc_publish_post', $post_id);

	if ( defined('WP_IMPORTING') )
		return;

	if ( get_option('default_pingback_flag') )
		add_post_meta( $post_id, '_pingme', '1' );
	add_post_meta( $post_id, '_encloseme', '1' );

	wp_schedule_single_event(time(), 'do_pings');
}

/**
 * Determines which fields of posts are to be saved in revisions.
 *
 * Does two things. If passed a post *array*, it will return a post array ready
 * to be inserted into the posts table as a post revision. Otherwise, returns
 * an array whose keys are the post fields to be saved for post revisions.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 * @access private
 * @uses apply_filters() Calls '_wp_post_revision_fields' on 'title', 'content' and 'excerpt' fields.
 *
 * @param array $post Optional a post array to be processed for insertion as a post revision.
 * @param bool $autosave optional Is the revision an autosave?
 * @return array Post array ready to be inserted as a post revision or array of fields that can be versioned.
 */
function _wp_post_revision_fields( $post = null, $autosave = false ) {
	static $fields = false;

	if ( !$fields ) {
		// Allow these to be versioned
		$fields = array(
			'post_title' => __( 'Title' ),
			'post_content' => __( 'Content' ),
			'post_excerpt' => __( 'Excerpt' ),
		);

		// Runs only once
		$fields = apply_filters( '_wp_post_revision_fields', $fields );

		// 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] );
	}

	if ( !is_array($post) )
		return $fields;

	$return = array();
	foreach ( array_intersect( array_keys( $post ), array_keys( $fields ) ) as $field )
		$return[$field] = $post[$field];

	$return['post_parent']   = $post['ID'];
	$return['post_status']   = 'inherit';
	$return['post_type']     = 'revision';
	$return['post_name']     = $autosave ? "$post[ID]-autosave" : "$post[ID]-revision";
	$return['post_date']     = isset($post['post_modified']) ? $post['post_modified'] : '';
	$return['post_date_gmt'] = isset($post['post_modified_gmt']) ? $post['post_modified_gmt'] : '';

	return $return;
}

/**
 * Saves an already existing post as a post revision.
 *
 * Typically used immediately prior to post updates.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses _wp_put_post_revision()
 *
 * @param int $post_id The ID of the post to save as a revision.
 * @return mixed Null or 0 if error, new revision ID, if success.
 */
function wp_save_post_revision( $post_id ) {
	// We do autosaves manually with wp_create_post_autosave()
	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
		return;

	// WP_POST_REVISIONS = 0, false
	if ( ! WP_POST_REVISIONS )
		return;

	if ( !$post = get_post( $post_id, ARRAY_A ) )
		return;

	if ( 'auto-draft' == $post['post_status'] )
		return;

	if ( !post_type_supports($post['post_type'], 'revisions') )
		return;

	$return = _wp_put_post_revision( $post );

	// WP_POST_REVISIONS = true (default), -1
	if ( !is_numeric( WP_POST_REVISIONS ) || WP_POST_REVISIONS < 0 )
		return $return;

	// all revisions and (possibly) one autosave
	$revisions = wp_get_post_revisions( $post_id, array( 'order' => 'ASC' ) );

	// WP_POST_REVISIONS = (int) (# of autosaves to save)
	$delete = count($revisions) - WP_POST_REVISIONS;

	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 containing the information that was autosaved for the
 * specified post.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param int $post_id The post ID.
 * @return object|bool The autosaved data or false on failure or when no autosave exists.
 */
function wp_get_post_autosave( $post_id ) {

	if ( !$post = get_post( $post_id ) )
		return false;

	$q = array(
		'name' => "{$post->ID}-autosave",
		'post_parent' => $post->ID,
		'post_type' => 'revision',
		'post_status' => 'inherit'
	);

	// Use WP_Query so that the result gets cached
	$autosave_query = new WP_Query;

	add_action( 'parse_query', '_wp_get_post_autosave_hack' );
	$autosave = $autosave_query->query( $q );
	remove_action( 'parse_query', '_wp_get_post_autosave_hack' );

	if ( $autosave && is_array($autosave) && is_object($autosave[0]) )
		return $autosave[0];

	return false;
}

/**
 * Internally used to hack WP_Query into submission.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param object $query WP_Query object
 */
function _wp_get_post_autosave_hack( $query ) {
	$query->is_single = false;
}

/**
 * Determines if the specified post is a revision.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param int|object $post Post ID or post object.
 * @return bool|int False if not a revision, ID of revision's parent otherwise.
 */
function wp_is_post_revision( $post ) {
	if ( !$post = wp_get_post_revision( $post ) )
		return false;
	return (int) $post->post_parent;
}

/**
 * Determines if the specified post is an autosave.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @param int|object $post Post ID or post object.
 * @return bool|int False if not a revision, ID of autosave's parent otherwise
 */
function wp_is_post_autosave( $post ) {
	if ( !$post = wp_get_post_revision( $post ) )
		return false;
	if ( "{$post->post_parent}-autosave" !== $post->post_name )
		return false;
	return (int) $post->post_parent;
}

/**
 * Inserts post data into the posts table as a post revision.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses wp_insert_post()
 *
 * @param int|object|array $post Post ID, post object OR post array.
 * @param bool $autosave Optional. Is the revision an autosave?
 * @return mixed Null 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;

	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_fields( $post, $autosave );
	$post = add_magic_quotes($post); //since data is from db

	$revision_id = wp_insert_post( $post );
	if ( is_wp_error($revision_id) )
		return $revision_id;

	if ( $revision_id )
		do_action( '_wp_put_post_revision', $revision_id );
	return $revision_id;
}

/**
 * Gets a post revision.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses get_post()
 *
 * @param int|object $post Post ID or post object
 * @param string $output Optional. OBJECT, ARRAY_A, or ARRAY_N.
 * @param string $filter Optional sanitation filter. @see sanitize_post()
 * @return mixed Null if error or post object if success
 */
function wp_get_post_revision(&$post, $output = OBJECT, $filter = 'raw') {
	$null = null;
	if ( !$revision = get_post( $post, OBJECT, $filter ) )
		return $revision;
	if ( 'revision' !== $revision->post_type )
		return $null;

	if ( $output == OBJECT ) {
		return $revision;
	} elseif ( $output == ARRAY_A ) {
		$_revision = get_object_vars($revision);
		return $_revision;
	} elseif ( $output == ARRAY_N ) {
		$_revision = array_values(get_object_vars($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.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses wp_get_post_revision()
 * @uses wp_update_post()
 * @uses do_action() Calls 'wp_restore_post_revision' on post ID and revision ID if wp_update_post()
 *  is successful.
 *
 * @param int|object $revision_id Revision ID or revision object.
 * @param array $fields Optional. What fields to restore from. Defaults to all.
 * @return mixed Null if error, false if no fields to restore, (int) post ID if success.
 */
function wp_restore_post_revision( $revision_id, $fields = null ) {
	if ( !$revision = wp_get_post_revision( $revision_id, ARRAY_A ) )
		return $revision;

	if ( !is_array( $fields ) )
		$fields = array_keys( _wp_post_revision_fields() );

	$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 = add_magic_quotes( $update ); //since data is from db

	$post_id = wp_update_post( $update );
	if ( is_wp_error( $post_id ) )
		return $post_id;

	if ( $post_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.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses wp_get_post_revision()
 * @uses wp_delete_post()
 *
 * @param int|object $revision_id Revision ID or revision object.
 * @return mixed Null or WP_Error if error, deleted post if success.
 */
function wp_delete_post_revision( $revision_id ) {
	if ( !$revision = wp_get_post_revision( $revision_id ) )
		return $revision;

	$delete = wp_delete_post( $revision->ID );
	if ( is_wp_error( $delete ) )
		return $delete;

	if ( $delete )
		do_action( 'wp_delete_post_revision', $revision->ID, $revision );

	return $delete;
}

/**
 * Returns all revisions of specified post.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses get_children()
 *
 * @param int|object $post_id Post ID or post object
 * @return array empty if no revisions
 */
function wp_get_post_revisions( $post_id = 0, $args = null ) {
	if ( ! WP_POST_REVISIONS )
		return array();
	if ( ( !$post = get_post( $post_id ) ) || empty( $post->ID ) )
		return array();

	$defaults = array( 'order' => 'DESC', 'orderby' => 'date' );
	$args = wp_parse_args( $args, $defaults );
	$args = array_merge( $args, array( 'post_parent' => $post->ID, 'post_type' => 'revision', 'post_status' => 'inherit' ) );

	if ( !$revisions = get_children( $args ) )
		return array();
	return $revisions;
}

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;

	return $post;
}

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( __('You do not have permission to preview drafts.') );

		add_filter('the_preview', '_set_preview');
	}
}

/**
 * Returns the post's parent's post_ID
 *
 * @since 3.1.0
 *
 * @param int $post_id
 *
 * @return int|bool false on error
 */
function wp_get_post_parent_id( $post_ID ) {
	$post = get_post( $post_ID );
	if ( !$post || is_wp_error( $post ) )
		return false;
	return (int) $post->post_parent;
}

/**
 * Checks the given subset of the post hierarchy for hierarchy loops.
 * Prevents loops from forming and breaks those that it finds.
 *
 * Attached to the wp_insert_post_parent filter.
 *
 * @since 3.1.0
 * @uses wp_find_hierarchy_loop()
 *
 * @param int $post_parent ID of the parent for the post we're checking.
 * @param int $post_ID ID of the post we're checking.
 *
 * @return int The new post_parent for the post.
 */
function wp_check_post_hierarchy_for_loops( $post_parent, $post_ID ) {
	// Nothing fancy here - bail
	if ( !$post_parent )
		return 0;

	// New post can't cause a loop
	if ( empty( $post_ID ) )
		return $post_parent;

	// Can't be its own parent
	if ( $post_parent == $post_ID )
		return 0;

	// Now look for larger loops

	if ( !$loop = wp_find_hierarchy_loop( 'wp_get_post_parent_id', $post_ID, $post_parent ) )
		return $post_parent; // No loop

	// Setting $post_parent to the given value causes a loop
	if ( isset( $loop[$post_ID] ) )
		return 0;

	// There's a loop, but it doesn't contain $post_ID. Break the loop.
	foreach ( array_keys( $loop ) as $loop_member )
		wp_update_post( array( 'ID' => $loop_member, 'post_parent' => 0 ) );

	return $post_parent;
}

/**
 * Returns an array of post format slugs to their translated and pretty display versions
 *
 * @since 3.1.0
 *
 * @return array The array of translations
 */
function get_post_format_strings() {
	$strings = array(
		'standard' => _x( 'Standard', 'Post format' ), // Special case. any value that evals to false will be considered standard
		'aside'    => _x( 'Aside',    'Post format' ),
		'chat'     => _x( 'Chat',     'Post format' ),
		'gallery'  => _x( 'Gallery',  'Post format' ),
		'link'     => _x( 'Link',     'Post format' ),
		'image'    => _x( 'Image',    'Post format' ),
		'quote'    => _x( 'Quote',    'Post format' ),
		'status'   => _x( 'Status',   'Post format' ),
		'video'    => _x( 'Video',    'Post format' ),
		'audio'    => _x( 'Audio',    'Post format' ),
	);
	return $strings;
}

/**
 * Retrieves an array of post format slugs.
 *
 * @since 3.1.0
 *
 * @return array The array of post format slugs.
 */
function get_post_format_slugs() {
	$slugs = array_keys( get_post_format_strings() );
	return array_combine( $slugs, $slugs );
}

/**
 * Returns a pretty, translated version of a post format slug
 *
 * @since 3.1.0
 *
 * @param string $slug A post format slug
 * @return string The translated post format name
 */
function get_post_format_string( $slug ) {
	$strings = get_post_format_strings();
	if ( !$slug )
		return $strings['standard'];
	else
		return ( isset( $strings[$slug] ) ) ? $strings[$slug] : '';
}

/**
 * Sets a post thumbnail.
 *
 * @since 3.1.0
 *
 * @param int|object $post Post ID or object where thumbnail should be attached.
 * @param int $thumbnail_id Thumbnail to attach.
 * @return bool True on success, false on failure.
 */
function set_post_thumbnail( $post, $thumbnail_id ) {
	$post = get_post( $post );
	$thumbnail_id = absint( $thumbnail_id );
	if ( $post && $thumbnail_id && get_post( $thumbnail_id ) ) {
		if ( $thumbnail_html = wp_get_attachment_image( $thumbnail_id, 'thumbnail' ) )
			return update_post_meta( $post->ID, '_thumbnail_id', $thumbnail_id );
		else
			return delete_post_meta( $post->ID, '_thumbnail_id' );
	}
	return false;
}

/**
 * Removes a post thumbnail.
 *
 * @since 3.3.0
 *
 * @param int|object $post Post ID or object where thumbnail should be removed from.
 * @return bool True on success, false on failure.
 */
function delete_post_thumbnail( $post ) {
	$post = get_post( $post );
	if ( $post )
		return delete_post_meta( $post->ID, '_thumbnail_id' );
	return false;
}

/**
 * Returns a link to a post format index.
 *
 * @since 3.1.0
 *
 * @param string $format Post format
 * @return string Link
 */
function get_post_format_link( $format ) {
	$term = get_term_by('slug', 'post-format-' . $format, 'post_format' );
	if ( ! $term || is_wp_error( $term ) )
		return false;
	return get_term_link( $term );
}

/**
 * Deletes auto-drafts for new posts that are > 7 days old
 *
 * @since 3.4.0
 */
function wp_delete_auto_drafts() {
	global $wpdb;

	// Cleanup old auto-drafts more than 7 days old
	$old_posts = $wpdb->get_col( "SELECT ID FROM $wpdb->posts WHERE post_status = 'auto-draft' AND DATE_SUB( NOW(), INTERVAL 7 DAY ) > post_date" );
	foreach ( (array) $old_posts as $delete )
		wp_delete_post( $delete, true ); // Force delete
}

/**
 * Filters the request to allow for the format prefix.
 *
 * @access private
 * @since 3.1.0
 */
function _post_format_request( $qvs ) {
	if ( ! isset( $qvs['post_format'] ) )
		return $qvs;
	$slugs = get_post_format_slugs();
	if ( isset( $slugs[ $qvs['post_format'] ] ) )
		$qvs['post_format'] = 'post-format-' . $slugs[ $qvs['post_format'] ];
	$tax = get_taxonomy( 'post_format' );
	if ( ! is_admin() )
		$qvs['post_type'] = $tax->object_type;
	return $qvs;
}
add_filter( 'request', '_post_format_request' );

/**
 * Filters the post format term link to remove the format prefix.
 *
 * @access private
 * @since 3.1.0
 */
function _post_format_link( $link, $term, $taxonomy ) {
	global $wp_rewrite;
	if ( 'post_format' != $taxonomy )
		return $link;
	if ( $wp_rewrite->get_extra_permastruct( $taxonomy ) ) {
		return str_replace( "/{$term->slug}", '/' . str_replace( 'post-format-', '', $term->slug ), $link );
	} else {
		$link = remove_query_arg( 'post_format', $link );
		return add_query_arg( 'post_format', str_replace( 'post-format-', '', $term->slug ), $link );
	}
}
add_filter( 'term_link', '_post_format_link', 10, 3 );

/**
 * Remove the post format prefix from the name property of the term object created by get_term().
 *
 * @access private
 * @since 3.1.0
 */
function _post_format_get_term( $term ) {
	if ( isset( $term->slug ) ) {
		$term->name = get_post_format_string( str_replace( 'post-format-', '', $term->slug ) );
	}
	return $term;
}
add_filter( 'get_post_format', '_post_format_get_term' );

/**
 * Remove the post format prefix from the name property of the term objects created by get_terms().
 *
 * @access private
 * @since 3.1.0
 */
function _post_format_get_terms( $terms, $taxonomies, $args ) {
	if ( in_array( 'post_format', (array) $taxonomies ) ) {
		if ( isset( $args['fields'] ) && 'names' == $args['fields'] ) {
			foreach( $terms as $order => $name ) {
				$terms[$order] = get_post_format_string( str_replace( 'post-format-', '', $name ) );
			}
		} else {
			foreach ( (array) $terms as $order => $term ) {
				if ( isset( $term->taxonomy ) && 'post_format' == $term->taxonomy ) {
					$terms[$order]->name = get_post_format_string( str_replace( 'post-format-', '', $term->slug ) );
				}
			}
		}
	}
	return $terms;
}
add_filter( 'get_terms', '_post_format_get_terms', 10, 3 );

/**
 * Remove the post format prefix from the name property of the term objects created by wp_get_object_terms().
 *
 * @access private
 * @since 3.1.0
 */
function _post_format_wp_get_object_terms( $terms ) {
	foreach ( (array) $terms as $order => $term ) {
		if ( isset( $term->taxonomy ) && 'post_format' == $term->taxonomy ) {
			$terms[$order]->name = get_post_format_string( str_replace( 'post-format-', '', $term->slug ) );
		}
	}
	return $terms;
}
add_filter( 'wp_get_object_terms', '_post_format_wp_get_object_terms' );

/**
 * Update the custom taxonomies' term counts when a post's status is changed. For example, default posts term counts (for custom taxonomies) don't include private / draft posts.
 *
 * @access private
 * @param string $new_status
 * @param string $old_status
 * @param object $post
 * @since 3.3.0
 */
function _update_term_count_on_transition_post_status( $new_status, $old_status, $post ) {
	// Update counts for the post's terms.
	foreach ( (array) get_object_taxonomies( $post->post_type ) as $taxonomy ) {
		$tt_ids = wp_get_object_terms( $post->ID, $taxonomy, array( 'fields' => 'tt_ids' ) );
		wp_update_term_count( $tt_ids, $taxonomy );
	}
}

/**
 * Adds any posts from the given ids to the cache that do not already exist in cache
 *
 * @since 3.4.0
 *
 * @access private
 *
 * @param array $post_ids ID list
 * @param bool $update_term_cache Whether to update the term cache. Default is true.
 * @param bool $update_meta_cache Whether to update the meta cache. Default is true.
 */
function _prime_post_caches( $ids, $update_term_cache = true, $update_meta_cache = true ) {
	global $wpdb;

	$non_cached_ids = _get_non_cached_ids( $ids, 'posts' );
	if ( !empty( $non_cached_ids ) ) {
		$fresh_posts = $wpdb->get_results( sprintf( "SELECT $wpdb->posts.* FROM $wpdb->posts WHERE ID IN (%s)", join( ",", $non_cached_ids ) ) );

		update_post_caches( $fresh_posts, 'any', $update_term_cache, $update_meta_cache );
	}
}