: str_replace(): Passing null to parameter #2 ($replace) of type array|string is deprecated in
'wp-admin/images/arrows-dark-vs.png',
'wp-admin/images/wp-logo.png',
'wp-admin/images/arrows-pr.png',
'wp-admin/images/arrows-dark.png',
'wp-admin/images/press-this.png',
'wp-admin/images/press-this-2x.png',
'wp-admin/images/arrows-vs-2x.png',
'wp-admin/images/welcome-icons.png',
'wp-admin/images/wp-logo-2x.png',
'wp-admin/images/stars-rtl-2x.png',
'wp-admin/images/arrows-dark-2x.png',
'wp-admin/images/arrows-pr-2x.png',
'wp-admin/images/menu-shadow-rtl.png',
'wp-admin/images/arrows-vs.png',
'wp-admin/images/about-search-2x.png',
'wp-admin/images/bubble_bg-rtl-2x.gif',
'wp-admin/images/wp-badge-2x.png',
'wp-admin/images/wordpress-logo-2x.png',
'wp-admin/images/bubble_bg-rtl.gif',
'wp-admin/images/wp-badge.png',
'wp-admin/images/menu-shadow.png',
'wp-admin/images/about-globe-2x.png',
'wp-admin/images/welcome-icons-2x.png',
'wp-admin/images/stars-rtl.png',
'wp-admin/images/wp-logo-vs-2x.png',
'wp-admin/images/about-updates-2x.png',
'wp-admin/css/colors.css',
'wp-admin/css/colors.min.css',
'wp-admin/css/colors-rtl.css',
'wp-admin/css/colors-rtl.min.css',
// Following files added back in 4.5, see #36083.
// 'wp-admin/css/media-rtl.min.css',
// 'wp-admin/css/media.min.css',
// 'wp-admin/css/farbtastic-rtl.min.css',
'wp-admin/images/lock-2x.png',
'wp-admin/images/lock.png',
'wp-admin/js/theme-preview.js',
'wp-admin/js/theme-install.min.js',
'wp-admin/js/theme-install.js',
'wp-admin/js/theme-preview.min.js',
'wp-includes/js/plupload/plupload.html4.js',
'wp-includes/js/plupload/plupload.html5.js',
'wp-includes/js/plupload/changelog.txt',
'wp-includes/js/plupload/plupload.silverlight.js',
'wp-includes/js/plupload/plupload.flash.js',
// Added back in 4.9 [41328], see #41755.
// 'wp-includes/js/plupload/plupload.js',
'wp-includes/js/tinymce/plugins/spellchecker',
'wp-includes/js/tinymce/plugins/inlinepopups',
'wp-includes/js/tinymce/plugins/media/js',
'wp-includes/js/tinymce/plugins/media/css',
'wp-includes/js/tinymce/plugins/wordpress/img',
'wp-includes/js/tinymce/plugins/wpdialogs/js',
'wp-includes/js/tinymce/plugins/wpeditimage/img',
'wp-includes/js/tinymce/plugins/wpeditimage/js',
'wp-includes/js/tinymce/plugins/wpeditimage/css',
'wp-includes/js/tinymce/plugins/wpgallery/img',
'wp-includes/js/tinymce/plugins/paste/js',
'wp-includes/js/tinymce/themes/advanced',
'wp-includes/js/tinymce/tiny_mce.js',
'wp-includes/js/tinymce/mark_loaded_src.js',
'wp-includes/js/tinymce/wp-tinymce-schema.js',
'wp-includes/js/tinymce/plugins/media/editor_plugin.js',
'wp-includes/js/tinymce/plugins/media/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/media/media.htm',
'wp-includes/js/tinymce/plugins/wpview/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/wpview/editor_plugin.js',
'wp-includes/js/tinymce/plugins/directionality/editor_plugin.js',
'wp-includes/js/tinymce/plugins/directionality/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/wordpress/editor_plugin.js',
'wp-includes/js/tinymce/plugins/wordpress/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/wpdialogs/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/wpdialogs/editor_plugin.js',
'wp-includes/js/tinymce/plugins/wpeditimage/editimage.html',
'wp-includes/js/tinymce/plugins/wpeditimage/editor_plugin.js',
'wp-includes/js/tinymce/plugins/wpeditimage/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/fullscreen/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/fullscreen/fullscreen.htm',
'wp-includes/js/tinymce/plugins/fullscreen/editor_plugin.js',
'wp-includes/js/tinymce/plugins/wplink/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/wplink/editor_plugin.js',
'wp-includes/js/tinymce/plugins/wpgallery/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/wpgallery/editor_plugin.js',
'wp-includes/js/tinymce/plugins/tabfocus/editor_plugin.js',
'wp-includes/js/tinymce/plugins/tabfocus/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/paste/editor_plugin.js',
'wp-includes/js/tinymce/plugins/paste/pasteword.htm',
'wp-includes/js/tinymce/plugins/paste/editor_plugin_src.js',
'wp-includes/js/tinymce/plugins/paste/pastetext.htm',
'wp-includes/js/tinymce/langs/wp-langs.php',
'wp-includes/js/jquery/ui/jquery.ui.accordion.min.js',
'wp-includes/js/jquery/ui/jquery.ui.autocomplete.min.js',
'wp-includes/js/jquery/ui/jquery.ui.button.min.js',
'wp-includes/js/jquery/ui/jquery.ui.core.min.js',
'wp-includes/js/jquery/ui/jquery.ui.datepicker.min.js',
'wp-includes/js/jquery/ui/jquery.ui.dialog.min.js',
'wp-includes/js/jquery/ui/jquery.ui.draggable.min.js',
'wp-includes/js/jquery/ui/jquery.ui.droppable.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-blind.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-bounce.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-clip.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-drop.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-explode.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-fade.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-fold.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-highlight.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-pulsate.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-scale.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-shake.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-slide.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect-transfer.min.js',
'wp-includes/js/jquery/ui/jquery.ui.effect.min.js',
'wp-includes/js/jquery/ui/jquery.ui.menu.min.js',
'wp-includes/js/jquery/ui/jquery.ui.mouse.min.js',
'wp-includes/js/jquery/ui/jquery.ui.position.min.js',
'wp-includes/js/jquery/ui/jquery.ui.progressbar.min.js',
'wp-includes/js/jquery/ui/jquery.ui.resizable.min.js',
'wp-includes/js/jquery/ui/jquery.ui.selectable.min.js',
'wp-includes/js/jquery/ui/jquery.ui.slider.min.js',
'wp-includes/js/jquery/ui/jquery.ui.sortable.min.js',
'wp-includes/js/jquery/ui/jquery.ui.spinner.min.js',
'wp-includes/js/jquery/ui/jquery.ui.tabs.min.js',
'wp-includes/js/jquery/ui/jquery.ui.tooltip.min.js',
'wp-includes/js/jquery/ui/jquery.ui.widget.min.js',
'wp-includes/js/tinymce/skins/wordpress/images/dashicon-no-alt.png',
'wp-admin/js/wp-fullscreen.js',
'wp-admin/js/wp-fullscreen.min.js',
'wp-includes/js/tinymce/wp-mce-help.php',
'wp-includes/js/tinymce/plugins/wpfullscreen',
'wp-includes/theme-compat/comments-popup.php',
'wp-admin/includes/class-wp-automatic-upgrader.php', // Wrong file name, see #37628.
'wp-includes/js/tinymce/plugins/wpembed',
'wp-includes/js/tinymce/plugins/media/moxieplayer.swf',
'wp-includes/js/tinymce/skins/lightgray/fonts/readme.md',
'wp-includes/js/tinymce/skins/lightgray/fonts/tinymce-small.json',
'wp-includes/js/tinymce/skins/lightgray/fonts/tinymce.json',
'wp-includes/js/tinymce/skins/lightgray/skin.ie7.min.css',
'wp-admin/css/press-this-editor-rtl.css',
'wp-admin/css/press-this-editor-rtl.min.css',
'wp-admin/css/press-this-editor.css',
'wp-admin/css/press-this-editor.min.css',
'wp-admin/css/press-this-rtl.css',
'wp-admin/css/press-this-rtl.min.css',
'wp-admin/css/press-this.css',
'wp-admin/css/press-this.min.css',
'wp-admin/includes/class-wp-press-this.php',
'wp-admin/js/bookmarklet.js',
'wp-admin/js/bookmarklet.min.js',
'wp-admin/js/press-this.js',
'wp-admin/js/press-this.min.js',
'wp-includes/js/mediaelement/background.png',
'wp-includes/js/mediaelement/bigplay.png',
'wp-includes/js/mediaelement/bigplay.svg',
'wp-includes/js/mediaelement/controls.png',
'wp-includes/js/mediaelement/controls.svg',
'wp-includes/js/mediaelement/flashmediaelement.swf',
'wp-includes/js/mediaelement/froogaloop.min.js',
'wp-includes/js/mediaelement/jumpforward.png',
'wp-includes/js/mediaelement/loading.gif',
'wp-includes/js/mediaelement/silverlightmediaelement.xap',
'wp-includes/js/mediaelement/skipback.png',
'wp-includes/js/plupload/plupload.flash.swf',
'wp-includes/js/plupload/plupload.full.min.js',
'wp-includes/js/plupload/plupload.silverlight.xap',
'wp-includes/js/swfupload/plugins',
'wp-includes/js/swfupload/swfupload.swf',
'wp-includes/js/mediaelement/lang',
'wp-includes/js/mediaelement/mediaelement-flash-audio-ogg.swf',
'wp-includes/js/mediaelement/mediaelement-flash-audio.swf',
'wp-includes/js/mediaelement/mediaelement-flash-video-hls.swf',
'wp-includes/js/mediaelement/mediaelement-flash-video-mdash.swf',
'wp-includes/js/mediaelement/mediaelement-flash-video.swf',
'wp-includes/js/mediaelement/renderers/dailymotion.js',
'wp-includes/js/mediaelement/renderers/dailymotion.min.js',
'wp-includes/js/mediaelement/renderers/facebook.js',
'wp-includes/js/mediaelement/renderers/facebook.min.js',
'wp-includes/js/mediaelement/renderers/soundcloud.js',
'wp-includes/js/mediaelement/renderers/soundcloud.min.js',
'wp-includes/js/mediaelement/renderers/twitch.js',
'wp-includes/js/mediaelement/renderers/twitch.min.js',
'wp-includes/js/codemirror/jshint.js',
'wp-includes/js/tinymce/wp-tinymce.js.gz',
'wp-includes/js/wp-a11y.js', // Moved to: wp-includes/js/dist/a11y.js
'wp-includes/js/wp-a11y.min.js', // Moved to: wp-includes/js/dist/a11y.min.js
'wp-admin/js/wp-fullscreen-stub.js',
'wp-admin/js/wp-fullscreen-stub.min.js',
'wp-admin/css/ie.min.css',
'wp-admin/css/ie-rtl.css',
'wp-admin/css/ie-rtl.min.css',
'wp-includes/js/jquery/ui/position.min.js',
'wp-includes/js/jquery/ui/widget.min.js',
'wp-includes/blocks/classic/block.json',
'wp-admin/images/freedoms.png',
'wp-admin/images/privacy.png',
'wp-admin/images/about-badge.svg',
'wp-admin/images/about-color-palette.svg',
'wp-admin/images/about-color-palette-vert.svg',
'wp-admin/images/about-header-brushes.svg',
'wp-includes/block-patterns/large-header.php',
'wp-includes/block-patterns/heading-paragraph.php',
'wp-includes/block-patterns/quote.php',
'wp-includes/block-patterns/text-three-columns-buttons.php',
'wp-includes/block-patterns/two-buttons.php',
'wp-includes/block-patterns/two-images.php',
'wp-includes/block-patterns/three-buttons.php',
'wp-includes/block-patterns/text-two-columns-with-images.php',
'wp-includes/block-patterns/text-two-columns.php',
'wp-includes/block-patterns/large-header-button.php',
'wp-includes/blocks/subhead',
'wp-includes/css/dist/editor/editor-styles.css',
'wp-includes/css/dist/editor/editor-styles.min.css',
'wp-includes/css/dist/editor/editor-styles-rtl.css',
'wp-includes/css/dist/editor/editor-styles-rtl.min.css',
'wp-includes/blocks/heading/editor.css',
'wp-includes/blocks/heading/editor.min.css',
'wp-includes/blocks/heading/editor-rtl.css',
'wp-includes/blocks/heading/editor-rtl.min.css',
'wp-includes/blocks/query-title/editor.css',
'wp-includes/blocks/query-title/editor.min.css',
'wp-includes/blocks/query-title/editor-rtl.css',
'wp-includes/blocks/query-title/editor-rtl.min.css',
'wp-includes/blocks/tag-cloud/editor.css',
'wp-includes/blocks/tag-cloud/editor.min.css',
'wp-includes/blocks/tag-cloud/editor-rtl.css',
'wp-includes/blocks/tag-cloud/editor-rtl.min.css',
'wp-includes/blocks/post-comments.php',
'wp-includes/blocks/post-comments',
'wp-includes/blocks/comments-query-loop',
'wp-includes/images/wlw',
'wp-includes/wlwmanifest.xml',
'wp-includes/random_compat',
'wp-includes/navigation-fallback.php',
'wp-includes/blocks/navigation/view-modal.min.js',
'wp-includes/blocks/navigation/view-modal.js',
'wp-includes/ID3/license.commercial.txt',
'wp-includes/blocks/query/style-rtl.min.css',
'wp-includes/blocks/query/style.min.css',
'wp-includes/blocks/query/style-rtl.css',
'wp-includes/blocks/query/style.css',
'wp-admin/images/about-header-privacy.svg',
'wp-admin/images/about-header-about.svg',
'wp-admin/images/about-header-credits.svg',
'wp-admin/images/about-header-freedoms.svg',
'wp-admin/images/about-header-contribute.svg',
'wp-admin/images/about-header-background.svg',
'wp-includes/blocks/block/editor.css',
'wp-includes/blocks/block/editor.min.css',
'wp-includes/blocks/block/editor-rtl.css',
'wp-includes/blocks/block/editor-rtl.min.css',
* Stores Requests files to be preloaded and deleted.
* For classes/interfaces, use the class/interface name
* All other files/directories should not have a key.
* @global array $_old_requests_files
* @name $_old_requests_files
global $_old_requests_files;
$_old_requests_files = array(
'Requests_Auth' => 'wp-includes/Requests/Auth.php',
'Requests_Hooker' => 'wp-includes/Requests/Hooker.php',
'Requests_Proxy' => 'wp-includes/Requests/Proxy.php',
'Requests_Transport' => 'wp-includes/Requests/Transport.php',
'Requests_Auth_Basic' => 'wp-includes/Requests/Auth/Basic.php',
'Requests_Cookie_Jar' => 'wp-includes/Requests/Cookie/Jar.php',
'Requests_Exception_HTTP' => 'wp-includes/Requests/Exception/HTTP.php',
'Requests_Exception_Transport' => 'wp-includes/Requests/Exception/Transport.php',
'Requests_Exception_HTTP_304' => 'wp-includes/Requests/Exception/HTTP/304.php',
'Requests_Exception_HTTP_305' => 'wp-includes/Requests/Exception/HTTP/305.php',
'Requests_Exception_HTTP_306' => 'wp-includes/Requests/Exception/HTTP/306.php',
'Requests_Exception_HTTP_400' => 'wp-includes/Requests/Exception/HTTP/400.php',
'Requests_Exception_HTTP_401' => 'wp-includes/Requests/Exception/HTTP/401.php',
'Requests_Exception_HTTP_402' => 'wp-includes/Requests/Exception/HTTP/402.php',
'Requests_Exception_HTTP_403' => 'wp-includes/Requests/Exception/HTTP/403.php',
'Requests_Exception_HTTP_404' => 'wp-includes/Requests/Exception/HTTP/404.php',
'Requests_Exception_HTTP_405' => 'wp-includes/Requests/Exception/HTTP/405.php',
'Requests_Exception_HTTP_406' => 'wp-includes/Requests/Exception/HTTP/406.php',
'Requests_Exception_HTTP_407' => 'wp-includes/Requests/Exception/HTTP/407.php',
'Requests_Exception_HTTP_408' => 'wp-includes/Requests/Exception/HTTP/408.php',
'Requests_Exception_HTTP_409' => 'wp-includes/Requests/Exception/HTTP/409.php',
'Requests_Exception_HTTP_410' => 'wp-includes/Requests/Exception/HTTP/410.php',
'Requests_Exception_HTTP_411' => 'wp-includes/Requests/Exception/HTTP/411.php',
'Requests_Exception_HTTP_412' => 'wp-includes/Requests/Exception/HTTP/412.php',
'Requests_Exception_HTTP_413' => 'wp-includes/Requests/Exception/HTTP/413.php',
'Requests_Exception_HTTP_414' => 'wp-includes/Requests/Exception/HTTP/414.php',
'Requests_Exception_HTTP_415' => 'wp-includes/Requests/Exception/HTTP/415.php',
'Requests_Exception_HTTP_416' => 'wp-includes/Requests/Exception/HTTP/416.php',
'Requests_Exception_HTTP_417' => 'wp-includes/Requests/Exception/HTTP/417.php',
'Requests_Exception_HTTP_418' => 'wp-includes/Requests/Exception/HTTP/418.php',
'Requests_Exception_HTTP_428' => 'wp-includes/Requests/Exception/HTTP/428.php',
'Requests_Exception_HTTP_429' => 'wp-includes/Requests/Exception/HTTP/429.php',
'Requests_Exception_HTTP_431' => 'wp-includes/Requests/Exception/HTTP/431.php',
'Requests_Exception_HTTP_500' => 'wp-includes/Requests/Exception/HTTP/500.php',
'Requests_Exception_HTTP_501' => 'wp-includes/Requests/Exception/HTTP/501.php',
'Requests_Exception_HTTP_502' => 'wp-includes/Requests/Exception/HTTP/502.php',
'Requests_Exception_HTTP_503' => 'wp-includes/Requests/Exception/HTTP/503.php',
'Requests_Exception_HTTP_504' => 'wp-includes/Requests/Exception/HTTP/504.php',
'Requests_Exception_HTTP_505' => 'wp-includes/Requests/Exception/HTTP/505.php',
'Requests_Exception_HTTP_511' => 'wp-includes/Requests/Exception/HTTP/511.php',
'Requests_Exception_HTTP_Unknown' => 'wp-includes/Requests/Exception/HTTP/Unknown.php',
'Requests_Exception_Transport_cURL' => 'wp-includes/Requests/Exception/Transport/cURL.php',
'Requests_Proxy_HTTP' => 'wp-includes/Requests/Proxy/HTTP.php',
'Requests_Response_Headers' => 'wp-includes/Requests/Response/Headers.php',
'Requests_Transport_cURL' => 'wp-includes/Requests/Transport/cURL.php',
'Requests_Transport_fsockopen' => 'wp-includes/Requests/Transport/fsockopen.php',
'Requests_Utility_CaseInsensitiveDictionary' => 'wp-includes/Requests/Utility/CaseInsensitiveDictionary.php',
'Requests_Utility_FilteredIterator' => 'wp-includes/Requests/Utility/FilteredIterator.php',
'Requests_Cookie' => 'wp-includes/Requests/Cookie.php',
'Requests_Exception' => 'wp-includes/Requests/Exception.php',
'Requests_Hooks' => 'wp-includes/Requests/Hooks.php',
'Requests_IDNAEncoder' => 'wp-includes/Requests/IDNAEncoder.php',
'Requests_IPv6' => 'wp-includes/Requests/IPv6.php',
'Requests_IRI' => 'wp-includes/Requests/IRI.php',
'Requests_Response' => 'wp-includes/Requests/Response.php',
'Requests_SSL' => 'wp-includes/Requests/SSL.php',
'Requests_Session' => 'wp-includes/Requests/Session.php',
'wp-includes/Requests/Auth/',
'wp-includes/Requests/Cookie/',
'wp-includes/Requests/Exception/HTTP/',
'wp-includes/Requests/Exception/Transport/',
'wp-includes/Requests/Exception/',
'wp-includes/Requests/Proxy/',
'wp-includes/Requests/Response/',
'wp-includes/Requests/Transport/',
'wp-includes/Requests/Utility/',
* Stores new files in wp-content to copy
* The contents of this array indicate any new bundled plugins/themes which
* should be installed with the WordPress Upgrade. These items will not be
* re-installed in future upgrades, this behavior is controlled by the
* introduced version present here being older than the current installed version.
* The content of this array should follow the following format:
* Filename (relative to wp-content) => Introduced version
* Directories should be noted by suffixing it with a trailing slash (/)
* @since 4.7.0 New themes were not automatically installed for 4.4-4.6 on
* upgrade. New themes are now installed again. To disable new
* themes from being installed on upgrade, explicitly define
* CORE_UPGRADE_SKIP_NEW_BUNDLED as true.
* @global array $_new_bundled_files
* @name $_new_bundled_files
global $_new_bundled_files;
$_new_bundled_files = array(
'plugins/akismet/' => '2.0',
'themes/twentyten/' => '3.0',
'themes/twentyeleven/' => '3.2',
'themes/twentytwelve/' => '3.5',
'themes/twentythirteen/' => '3.6',
'themes/twentyfourteen/' => '3.8',
'themes/twentyfifteen/' => '4.1',
'themes/twentysixteen/' => '4.4',
'themes/twentyseventeen/' => '4.7',
'themes/twentynineteen/' => '5.0',
'themes/twentytwenty/' => '5.3',
'themes/twentytwentyone/' => '5.6',
'themes/twentytwentytwo/' => '5.9',
'themes/twentytwentythree/' => '6.1',
'themes/twentytwentyfour/' => '6.4',
* Upgrades the core of WordPress.
* This will create a .maintenance file at the base of the WordPress directory
* to ensure that people can not access the website, when the files are being
* copied to their locations.
* The files in the `$_old_files` list will be removed and the new files
* copied from the zip file after the database is upgraded.
* The files in the `$_new_bundled_files` list will be added to the installation
* if the version is greater than or equal to the old version being upgraded.
* The steps for the upgrader for after the new release is downloaded and
* 1. Test unzipped location for select files to ensure that unzipped worked.
* 2. Create the .maintenance file in current WordPress base.
* 3. Copy new WordPress directory over old WordPress files.
* 4. Upgrade WordPress to new version.
* 4.1. Copy all files/folders other than wp-content
* 4.2. Copy any language files to WP_LANG_DIR (which may differ from WP_CONTENT_DIR
* 4.3. Copy any new bundled themes/plugins to their respective locations
* 5. Delete new WordPress directory path.
* 6. Delete .maintenance file.
* 8. Delete 'update_core' option.
* There are several areas of failure. For instance if PHP times out before step
* 6, then you will not be able to access any portion of your site. Also, since
* the upgrade will not continue where it left off, you will not be able to
* automatically remove old files and remove the 'update_core' option. This
* If the copy of the new WordPress over the old fails, then the worse is that
* the new WordPress directory will remain.
* If it is assumed that every file will be copied over, including plugins and
* themes, then if you edit the default theme, you should rename it, so that
* @global WP_Filesystem_Base $wp_filesystem WordPress filesystem subclass.
* @global array $_old_files
* @global array $_old_requests_files
* @global array $_new_bundled_files
* @global wpdb $wpdb WordPress database abstraction object.
* @global string $wp_version
* @global string $required_php_version
* @global string $required_mysql_version
* @param string $from New release unzipped path.
* @param string $to Path to old WordPress installation.
* @return string|WP_Error New WordPress version on success, WP_Error on failure.
function update_core( $from, $to ) {
global $wp_filesystem, $_old_files, $_old_requests_files, $_new_bundled_files, $wpdb;
if ( function_exists( 'set_time_limit' ) ) {
* Merge the old Requests files and directories into the `$_old_files`.
* Then preload these Requests files first, before the files are deleted
* and replaced to ensure the code is in memory if needed.
$_old_files = array_merge( $_old_files, array_values( $_old_requests_files ) );
_preload_old_requests_classes_and_interfaces( $to );
* Filters feedback messages displayed during the core update process.
* The filter is first evaluated after the zip file for the latest version
* has been downloaded and unzipped. It is evaluated five more times during
* 1. Before WordPress begins the core upgrade process.
* 2. Before Maintenance Mode is enabled.
* 3. Before WordPress begins copying over the necessary files.
* 4. Before Maintenance Mode is disabled.
* 5. Before the database is upgraded.
* @param string $feedback The core update feedback messages.
apply_filters( 'update_feedback', __( 'Verifying the unpacked files…' ) );
// Confidence check the unzipped distribution.
$roots = array( '/wordpress/', '/wordpress-mu/' );
foreach ( $roots as $root ) {
if ( $wp_filesystem->exists( $from . $root . 'readme.html' )