Adding upstream version 6.4.3+dfsg1.upstream/6.4.3+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2137 insertions, 0 deletions

diff --git a/wp-includes/widgets.php b/wp-includes/widgets.php
new file mode 100644
index 0000000..c568cbe
--- /dev/null
+++ b/wp-includes/widgets.php
@@ -0,0 +1,2137 @@
+<?php
+/**
+ * Core Widgets API
+ *
+ * This API is used for creating dynamic sidebar without hardcoding functionality into
+ * themes
+ *
+ * Includes both internal WordPress routines and theme-use routines.
+ *
+ * This functionality was found in a plugin before the WordPress 2.2 release, which
+ * included it in the core from that point on.
+ *
+ * @link https://wordpress.org/documentation/article/manage-wordpress-widgets/
+ * @link https://developer.wordpress.org/themes/functionality/widgets/
+ *
+ * @package WordPress
+ * @subpackage Widgets
+ * @since 2.2.0
+ */
+
+//
+// Global Variables.
+//
+
+/** @ignore */
+global $wp_registered_sidebars, $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_widget_updates;
+
+/**
+ * Stores the sidebars, since many themes can have more than one.
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ * @since 2.2.0
+ */
+$wp_registered_sidebars = array();
+
+/**
+ * Stores the registered widgets.
+ *
+ * @global array $wp_registered_widgets
+ * @since 2.2.0
+ */
+$wp_registered_widgets = array();
+
+/**
+ * Stores the registered widget controls (options).
+ *
+ * @global array $wp_registered_widget_controls
+ * @since 2.2.0
+ */
+$wp_registered_widget_controls = array();
+/**
+ * @global array $wp_registered_widget_updates
+ */
+$wp_registered_widget_updates = array();
+
+/**
+ * Private
+ *
+ * @global array $_wp_sidebars_widgets
+ */
+$_wp_sidebars_widgets = array();
+
+/**
+ * Private
+ *
+ * @global array $_wp_deprecated_widgets_callbacks
+ */
+$GLOBALS['_wp_deprecated_widgets_callbacks'] = array(
+	'wp_widget_pages',
+	'wp_widget_pages_control',
+	'wp_widget_calendar',
+	'wp_widget_calendar_control',
+	'wp_widget_archives',
+	'wp_widget_archives_control',
+	'wp_widget_links',
+	'wp_widget_meta',
+	'wp_widget_meta_control',
+	'wp_widget_search',
+	'wp_widget_recent_entries',
+	'wp_widget_recent_entries_control',
+	'wp_widget_tag_cloud',
+	'wp_widget_tag_cloud_control',
+	'wp_widget_categories',
+	'wp_widget_categories_control',
+	'wp_widget_text',
+	'wp_widget_text_control',
+	'wp_widget_rss',
+	'wp_widget_rss_control',
+	'wp_widget_recent_comments',
+	'wp_widget_recent_comments_control',
+);
+
+//
+// Template tags & API functions.
+//
+
+/**
+ * Register a widget
+ *
+ * Registers a WP_Widget widget
+ *
+ * @since 2.8.0
+ * @since 4.6.0 Updated the `$widget` parameter to also accept a WP_Widget instance object
+ *              instead of simply a `WP_Widget` subclass name.
+ *
+ * @see WP_Widget
+ *
+ * @global WP_Widget_Factory $wp_widget_factory
+ *
+ * @param string|WP_Widget $widget Either the name of a `WP_Widget` subclass or an instance of a `WP_Widget` subclass.
+ */
+function register_widget( $widget ) {
+	global $wp_widget_factory;
+
+	$wp_widget_factory->register( $widget );
+}
+
+/**
+ * Unregisters a widget.
+ *
+ * Unregisters a WP_Widget widget. Useful for un-registering default widgets.
+ * Run within a function hooked to the {@see 'widgets_init'} action.
+ *
+ * @since 2.8.0
+ * @since 4.6.0 Updated the `$widget` parameter to also accept a WP_Widget instance object
+ *              instead of simply a `WP_Widget` subclass name.
+ *
+ * @see WP_Widget
+ *
+ * @global WP_Widget_Factory $wp_widget_factory
+ *
+ * @param string|WP_Widget $widget Either the name of a `WP_Widget` subclass or an instance of a `WP_Widget` subclass.
+ */
+function unregister_widget( $widget ) {
+	global $wp_widget_factory;
+
+	$wp_widget_factory->unregister( $widget );
+}
+
+/**
+ * Creates multiple sidebars.
+ *
+ * If you wanted to quickly create multiple sidebars for a theme or internally.
+ * This function will allow you to do so. If you don't pass the 'name' and/or
+ * 'id' in `$args`, then they will be built for you.
+ *
+ * @since 2.2.0
+ *
+ * @see register_sidebar() The second parameter is documented by register_sidebar() and is the same here.
+ *
+ * @global array $wp_registered_sidebars The new sidebars are stored in this array by sidebar ID.
+ *
+ * @param int          $number Optional. Number of sidebars to create. Default 1.
+ * @param array|string $args {
+ *     Optional. Array or string of arguments for building a sidebar.
+ *
+ *     @type string $id   The base string of the unique identifier for each sidebar. If provided, and multiple
+ *                        sidebars are being defined, the ID will have "-2" appended, and so on.
+ *                        Default 'sidebar-' followed by the number the sidebar creation is currently at.
+ *     @type string $name The name or title for the sidebars displayed in the admin dashboard. If registering
+ *                        more than one sidebar, include '%d' in the string as a placeholder for the uniquely
+ *                        assigned number for each sidebar.
+ *                        Default 'Sidebar' for the first sidebar, otherwise 'Sidebar %d'.
+ * }
+ */
+function register_sidebars( $number = 1, $args = array() ) {
+	global $wp_registered_sidebars;
+	$number = (int) $number;
+
+	if ( is_string( $args ) ) {
+		parse_str( $args, $args );
+	}
+
+	for ( $i = 1; $i <= $number; $i++ ) {
+		$_args = $args;
+
+		if ( $number > 1 ) {
+			if ( isset( $args['name'] ) ) {
+				$_args['name'] = sprintf( $args['name'], $i );
+			} else {
+				/* translators: %d: Sidebar number. */
+				$_args['name'] = sprintf( __( 'Sidebar %d' ), $i );
+			}
+		} else {
+			$_args['name'] = isset( $args['name'] ) ? $args['name'] : __( 'Sidebar' );
+		}
+
+		/*
+		 * Custom specified ID's are suffixed if they exist already.
+		 * Automatically generated sidebar names need to be suffixed regardless starting at -0.
+		 */
+		if ( isset( $args['id'] ) ) {
+			$_args['id'] = $args['id'];
+			$n           = 2; // Start at -2 for conflicting custom IDs.
+			while ( is_registered_sidebar( $_args['id'] ) ) {
+				$_args['id'] = $args['id'] . '-' . $n++;
+			}
+		} else {
+			$n = count( $wp_registered_sidebars );
+			do {
+				$_args['id'] = 'sidebar-' . ++$n;
+			} while ( is_registered_sidebar( $_args['id'] ) );
+		}
+		register_sidebar( $_args );
+	}
+}
+
+/**
+ * Builds the definition for a single sidebar and returns the ID.
+ *
+ * Accepts either a string or an array and then parses that against a set
+ * of default arguments for the new sidebar. WordPress will automatically
+ * generate a sidebar ID and name based on the current number of registered
+ * sidebars if those arguments are not included.
+ *
+ * When allowing for automatic generation of the name and ID parameters, keep
+ * in mind that the incrementor for your sidebar can change over time depending
+ * on what other plugins and themes are installed.
+ *
+ * If theme support for 'widgets' has not yet been added when this function is
+ * called, it will be automatically enabled through the use of add_theme_support()
+ *
+ * @since 2.2.0
+ * @since 5.6.0 Added the `before_sidebar` and `after_sidebar` arguments.
+ * @since 5.9.0 Added the `show_in_rest` argument.
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ *
+ * @param array|string $args {
+ *     Optional. Array or string of arguments for the sidebar being registered.
+ *
+ *     @type string $name           The name or title of the sidebar displayed in the Widgets
+ *                                  interface. Default 'Sidebar $instance'.
+ *     @type string $id             The unique identifier by which the sidebar will be called.
+ *                                  Default 'sidebar-$instance'.
+ *     @type string $description    Description of the sidebar, displayed in the Widgets interface.
+ *                                  Default empty string.
+ *     @type string $class          Extra CSS class to assign to the sidebar in the Widgets interface.
+ *                                  Default empty.
+ *     @type string $before_widget  HTML content to prepend to each widget's HTML output when assigned
+ *                                  to this sidebar. Receives the widget's ID attribute as `%1$s`
+ *                                  and class name as `%2$s`. Default is an opening list item element.
+ *     @type string $after_widget   HTML content to append to each widget's HTML output when assigned
+ *                                  to this sidebar. Default is a closing list item element.
+ *     @type string $before_title   HTML content to prepend to the sidebar title when displayed.
+ *                                  Default is an opening h2 element.
+ *     @type string $after_title    HTML content to append to the sidebar title when displayed.
+ *                                  Default is a closing h2 element.
+ *     @type string $before_sidebar HTML content to prepend to the sidebar when displayed.
+ *                                  Receives the `$id` argument as `%1$s` and `$class` as `%2$s`.
+ *                                  Outputs after the {@see 'dynamic_sidebar_before'} action.
+ *                                  Default empty string.
+ *     @type string $after_sidebar  HTML content to append to the sidebar when displayed.
+ *                                  Outputs before the {@see 'dynamic_sidebar_after'} action.
+ *                                  Default empty string.
+ *     @type bool $show_in_rest     Whether to show this sidebar publicly in the REST API.
+ *                                  Defaults to only showing the sidebar to administrator users.
+ * }
+ * @return string Sidebar ID added to $wp_registered_sidebars global.
+ */
+function register_sidebar( $args = array() ) {
+	global $wp_registered_sidebars;
+
+	$i = count( $wp_registered_sidebars ) + 1;
+
+	$id_is_empty = empty( $args['id'] );
+
+	$defaults = array(
+		/* translators: %d: Sidebar number. */
+		'name'           => sprintf( __( 'Sidebar %d' ), $i ),
+		'id'             => "sidebar-$i",
+		'description'    => '',
+		'class'          => '',
+		'before_widget'  => '<li id="%1$s" class="widget %2$s">',
+		'after_widget'   => "</li>\n",
+		'before_title'   => '<h2 class="widgettitle">',
+		'after_title'    => "</h2>\n",
+		'before_sidebar' => '',
+		'after_sidebar'  => '',
+		'show_in_rest'   => false,
+	);
+
+	/**
+	 * Filters the sidebar default arguments.
+	 *
+	 * @since 5.3.0
+	 *
+	 * @see register_sidebar()
+	 *
+	 * @param array $defaults The default sidebar arguments.
+	 */
+	$sidebar = wp_parse_args( $args, apply_filters( 'register_sidebar_defaults', $defaults ) );
+
+	if ( $id_is_empty ) {
+		_doing_it_wrong(
+			__FUNCTION__,
+			sprintf(
+				/* translators: 1: The 'id' argument, 2: Sidebar name, 3: Recommended 'id' value. */
+				__( 'No %1$s was set in the arguments array for the "%2$s" sidebar. Defaulting to "%3$s". Manually set the %1$s to "%3$s" to silence this notice and keep existing sidebar content.' ),
+				'<code>id</code>',
+				$sidebar['name'],
+				$sidebar['id']
+			),
+			'4.2.0'
+		);
+	}
+
+	$wp_registered_sidebars[ $sidebar['id'] ] = $sidebar;
+
+	add_theme_support( 'widgets' );
+
+	/**
+	 * Fires once a sidebar has been registered.
+	 *
+	 * @since 3.0.0
+	 *
+	 * @param array $sidebar Parsed arguments for the registered sidebar.
+	 */
+	do_action( 'register_sidebar', $sidebar );
+
+	return $sidebar['id'];
+}
+
+/**
+ * Removes a sidebar from the list.
+ *
+ * @since 2.2.0
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ *
+ * @param string|int $sidebar_id The ID of the sidebar when it was registered.
+ */
+function unregister_sidebar( $sidebar_id ) {
+	global $wp_registered_sidebars;
+
+	unset( $wp_registered_sidebars[ $sidebar_id ] );
+}
+
+/**
+ * Checks if a sidebar is registered.
+ *
+ * @since 4.4.0
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ *
+ * @param string|int $sidebar_id The ID of the sidebar when it was registered.
+ * @return bool True if the sidebar is registered, false otherwise.
+ */
+function is_registered_sidebar( $sidebar_id ) {
+	global $wp_registered_sidebars;
+
+	return isset( $wp_registered_sidebars[ $sidebar_id ] );
+}
+
+/**
+ * Register an instance of a widget.
+ *
+ * The default widget option is 'classname' that can be overridden.
+ *
+ * The function can also be used to un-register widgets when `$output_callback`
+ * parameter is an empty string.
+ *
+ * @since 2.2.0
+ * @since 5.3.0 Formalized the existing and already documented `...$params` parameter
+ *              by adding it to the function signature.
+ * @since 5.8.0 Added show_instance_in_rest option.
+ *
+ * @global array $wp_registered_widgets            Uses stored registered widgets.
+ * @global array $wp_registered_widget_controls    Stores the registered widget controls (options).
+ * @global array $wp_registered_widget_updates
+ * @global array $_wp_deprecated_widgets_callbacks
+ *
+ * @param int|string $id              Widget ID.
+ * @param string     $name            Widget display title.
+ * @param callable   $output_callback Run when widget is called.
+ * @param array      $options {
+ *     Optional. An array of supplementary widget options for the instance.
+ *
+ *     @type string $classname             Class name for the widget's HTML container. Default is a shortened
+ *                                         version of the output callback name.
+ *     @type string $description           Widget description for display in the widget administration
+ *                                         panel and/or theme.
+ *     @type bool   $show_instance_in_rest Whether to show the widget's instance settings in the REST API.
+ *                                         Only available for WP_Widget based widgets.
+ * }
+ * @param mixed      ...$params       Optional additional parameters to pass to the callback function when it's called.
+ */
+function wp_register_sidebar_widget( $id, $name, $output_callback, $options = array(), ...$params ) {
+	global $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_widget_updates, $_wp_deprecated_widgets_callbacks;
+
+	$id = strtolower( $id );
+
+	if ( empty( $output_callback ) ) {
+		unset( $wp_registered_widgets[ $id ] );
+		return;
+	}
+
+	$id_base = _get_widget_id_base( $id );
+	if ( in_array( $output_callback, $_wp_deprecated_widgets_callbacks, true ) && ! is_callable( $output_callback ) ) {
+		unset( $wp_registered_widget_controls[ $id ] );
+		unset( $wp_registered_widget_updates[ $id_base ] );
+		return;
+	}
+
+	$defaults = array( 'classname' => $output_callback );
+	$options  = wp_parse_args( $options, $defaults );
+	$widget   = array(
+		'name'     => $name,
+		'id'       => $id,
+		'callback' => $output_callback,
+		'params'   => $params,
+	);
+	$widget   = array_merge( $widget, $options );
+
+	if ( is_callable( $output_callback ) && ( ! isset( $wp_registered_widgets[ $id ] ) || did_action( 'widgets_init' ) ) ) {
+
+		/**
+		 * Fires once for each registered widget.
+		 *
+		 * @since 3.0.0
+		 *
+		 * @param array $widget An array of default widget arguments.
+		 */
+		do_action( 'wp_register_sidebar_widget', $widget );
+		$wp_registered_widgets[ $id ] = $widget;
+	}
+}
+
+/**
+ * Retrieve description for widget.
+ *
+ * When registering widgets, the options can also include 'description' that
+ * describes the widget for display on the widget administration panel or
+ * in the theme.
+ *
+ * @since 2.5.0
+ *
+ * @global array $wp_registered_widgets
+ *
+ * @param int|string $id Widget ID.
+ * @return string|void Widget description, if available.
+ */
+function wp_widget_description( $id ) {
+	if ( ! is_scalar( $id ) ) {
+		return;
+	}
+
+	global $wp_registered_widgets;
+
+	if ( isset( $wp_registered_widgets[ $id ]['description'] ) ) {
+		return esc_html( $wp_registered_widgets[ $id ]['description'] );
+	}
+}
+
+/**
+ * Retrieve description for a sidebar.
+ *
+ * When registering sidebars a 'description' parameter can be included that
+ * describes the sidebar for display on the widget administration panel.
+ *
+ * @since 2.9.0
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ *
+ * @param string $id sidebar ID.
+ * @return string|void Sidebar description, if available.
+ */
+function wp_sidebar_description( $id ) {
+	if ( ! is_scalar( $id ) ) {
+		return;
+	}
+
+	global $wp_registered_sidebars;
+
+	if ( isset( $wp_registered_sidebars[ $id ]['description'] ) ) {
+		return wp_kses( $wp_registered_sidebars[ $id ]['description'], 'sidebar_description' );
+	}
+}
+
+/**
+ * Remove widget from sidebar.
+ *
+ * @since 2.2.0
+ *
+ * @param int|string $id Widget ID.
+ */
+function wp_unregister_sidebar_widget( $id ) {
+
+	/**
+	 * Fires just before a widget is removed from a sidebar.
+	 *
+	 * @since 3.0.0
+	 *
+	 * @param int|string $id The widget ID.
+	 */
+	do_action( 'wp_unregister_sidebar_widget', $id );
+
+	wp_register_sidebar_widget( $id, '', '' );
+	wp_unregister_widget_control( $id );
+}
+
+/**
+ * Registers widget control callback for customizing options.
+ *
+ * @since 2.2.0
+ * @since 5.3.0 Formalized the existing and already documented `...$params` parameter
+ *              by adding it to the function signature.
+ *
+ * @global array $wp_registered_widget_controls
+ * @global array $wp_registered_widget_updates
+ * @global array $wp_registered_widgets
+ * @global array $_wp_deprecated_widgets_callbacks
+ *
+ * @param int|string $id               Sidebar ID.
+ * @param string     $name             Sidebar display name.
+ * @param callable   $control_callback Run when sidebar is displayed.
+ * @param array      $options {
+ *     Optional. Array or string of control options. Default empty array.
+ *
+ *     @type int        $height  Never used. Default 200.
+ *     @type int        $width   Width of the fully expanded control form (but try hard to use the default width).
+ *                               Default 250.
+ *     @type int|string $id_base Required for multi-widgets, i.e widgets that allow multiple instances such as the
+ *                               text widget. The widget ID will end up looking like `{$id_base}-{$unique_number}`.
+ * }
+ * @param mixed      ...$params        Optional additional parameters to pass to the callback function when it's called.
+ */
+function wp_register_widget_control( $id, $name, $control_callback, $options = array(), ...$params ) {
+	global $wp_registered_widget_controls, $wp_registered_widget_updates, $wp_registered_widgets, $_wp_deprecated_widgets_callbacks;
+
+	$id      = strtolower( $id );
+	$id_base = _get_widget_id_base( $id );
+
+	if ( empty( $control_callback ) ) {
+		unset( $wp_registered_widget_controls[ $id ] );
+		unset( $wp_registered_widget_updates[ $id_base ] );
+		return;
+	}
+
+	if ( in_array( $control_callback, $_wp_deprecated_widgets_callbacks, true ) && ! is_callable( $control_callback ) ) {
+		unset( $wp_registered_widgets[ $id ] );
+		return;
+	}
+
+	if ( isset( $wp_registered_widget_controls[ $id ] ) && ! did_action( 'widgets_init' ) ) {
+		return;
+	}
+
+	$defaults          = array(
+		'width'  => 250,
+		'height' => 200,
+	); // Height is never used.
+	$options           = wp_parse_args( $options, $defaults );
+	$options['width']  = (int) $options['width'];
+	$options['height'] = (int) $options['height'];
+
+	$widget = array(
+		'name'     => $name,
+		'id'       => $id,
+		'callback' => $control_callback,
+		'params'   => $params,
+	);
+	$widget = array_merge( $widget, $options );
+
+	$wp_registered_widget_controls[ $id ] = $widget;
+
+	if ( isset( $wp_registered_widget_updates[ $id_base ] ) ) {
+		return;
+	}
+
+	if ( isset( $widget['params'][0]['number'] ) ) {
+		$widget['params'][0]['number'] = -1;
+	}
+
+	unset( $widget['width'], $widget['height'], $widget['name'], $widget['id'] );
+	$wp_registered_widget_updates[ $id_base ] = $widget;
+}
+
+/**
+ * Registers the update callback for a widget.
+ *
+ * @since 2.8.0
+ * @since 5.3.0 Formalized the existing and already documented `...$params` parameter
+ *              by adding it to the function signature.
+ *
+ * @global array $wp_registered_widget_updates
+ *
+ * @param string   $id_base         The base ID of a widget created by extending WP_Widget.
+ * @param callable $update_callback Update callback method for the widget.
+ * @param array    $options         Optional. Widget control options. See wp_register_widget_control().
+ *                                  Default empty array.
+ * @param mixed    ...$params       Optional additional parameters to pass to the callback function when it's called.
+ */
+function _register_widget_update_callback( $id_base, $update_callback, $options = array(), ...$params ) {
+	global $wp_registered_widget_updates;
+
+	if ( isset( $wp_registered_widget_updates[ $id_base ] ) ) {
+		if ( empty( $update_callback ) ) {
+			unset( $wp_registered_widget_updates[ $id_base ] );
+		}
+		return;
+	}
+
+	$widget = array(
+		'callback' => $update_callback,
+		'params'   => $params,
+	);
+
+	$widget                                   = array_merge( $widget, $options );
+	$wp_registered_widget_updates[ $id_base ] = $widget;
+}
+
+/**
+ * Registers the form callback for a widget.
+ *
+ * @since 2.8.0
+ * @since 5.3.0 Formalized the existing and already documented `...$params` parameter
+ *              by adding it to the function signature.
+ *
+ * @global array $wp_registered_widget_controls
+ *
+ * @param int|string $id            Widget ID.
+ * @param string     $name          Name attribute for the widget.
+ * @param callable   $form_callback Form callback.
+ * @param array      $options       Optional. Widget control options. See wp_register_widget_control().
+ *                                  Default empty array.
+ * @param mixed      ...$params     Optional additional parameters to pass to the callback function when it's called.
+ */
+
+function _register_widget_form_callback( $id, $name, $form_callback, $options = array(), ...$params ) {
+	global $wp_registered_widget_controls;
+
+	$id = strtolower( $id );
+
+	if ( empty( $form_callback ) ) {
+		unset( $wp_registered_widget_controls[ $id ] );
+		return;
+	}
+
+	if ( isset( $wp_registered_widget_controls[ $id ] ) && ! did_action( 'widgets_init' ) ) {
+		return;
+	}
+
+	$defaults          = array(
+		'width'  => 250,
+		'height' => 200,
+	);
+	$options           = wp_parse_args( $options, $defaults );
+	$options['width']  = (int) $options['width'];
+	$options['height'] = (int) $options['height'];
+
+	$widget = array(
+		'name'     => $name,
+		'id'       => $id,
+		'callback' => $form_callback,
+		'params'   => $params,
+	);
+	$widget = array_merge( $widget, $options );
+
+	$wp_registered_widget_controls[ $id ] = $widget;
+}
+
+/**
+ * Remove control callback for widget.
+ *
+ * @since 2.2.0
+ *
+ * @param int|string $id Widget ID.
+ */
+function wp_unregister_widget_control( $id ) {
+	wp_register_widget_control( $id, '', '' );
+}
+
+/**
+ * Display dynamic sidebar.
+ *
+ * By default this displays the default sidebar or 'sidebar-1'. If your theme specifies the 'id' or
+ * 'name' parameter for its registered sidebars you can pass an ID or name as the $index parameter.
+ * Otherwise, you can pass in a numerical index to display the sidebar at that index.
+ *
+ * @since 2.2.0
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ * @global array $wp_registered_widgets  Registered widgets.
+ *
+ * @param int|string $index Optional. Index, name or ID of dynamic sidebar. Default 1.
+ * @return bool True, if widget sidebar was found and called. False if not found or not called.
+ */
+function dynamic_sidebar( $index = 1 ) {
+	global $wp_registered_sidebars, $wp_registered_widgets;
+
+	if ( is_int( $index ) ) {
+		$index = "sidebar-$index";
+	} else {
+		$index = sanitize_title( $index );
+		foreach ( (array) $wp_registered_sidebars as $key => $value ) {
+			if ( sanitize_title( $value['name'] ) === $index ) {
+				$index = $key;
+				break;
+			}
+		}
+	}
+
+	$sidebars_widgets = wp_get_sidebars_widgets();
+	if ( empty( $wp_registered_sidebars[ $index ] ) || empty( $sidebars_widgets[ $index ] ) || ! is_array( $sidebars_widgets[ $index ] ) ) {
+		/** This action is documented in wp-includes/widget.php */
+		do_action( 'dynamic_sidebar_before', $index, false );
+		/** This action is documented in wp-includes/widget.php */
+		do_action( 'dynamic_sidebar_after', $index, false );
+		/** This filter is documented in wp-includes/widget.php */
+		return apply_filters( 'dynamic_sidebar_has_widgets', false, $index );
+	}
+
+	$sidebar = $wp_registered_sidebars[ $index ];
+
+	$sidebar['before_sidebar'] = sprintf( $sidebar['before_sidebar'], $sidebar['id'], $sidebar['class'] );
+
+	/**
+	 * Fires before widgets are rendered in a dynamic sidebar.
+	 *
+	 * Note: The action also fires for empty sidebars, and on both the front end
+	 * and back end, including the Inactive Widgets sidebar on the Widgets screen.
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param int|string $index       Index, name, or ID of the dynamic sidebar.
+	 * @param bool       $has_widgets Whether the sidebar is populated with widgets.
+	 *                                Default true.
+	 */
+	do_action( 'dynamic_sidebar_before', $index, true );
+
+	if ( ! is_admin() && ! empty( $sidebar['before_sidebar'] ) ) {
+		echo $sidebar['before_sidebar'];
+	}
+
+	$did_one = false;
+	foreach ( (array) $sidebars_widgets[ $index ] as $id ) {
+
+		if ( ! isset( $wp_registered_widgets[ $id ] ) ) {
+			continue;
+		}
+
+		$params = array_merge(
+			array(
+				array_merge(
+					$sidebar,
+					array(
+						'widget_id'   => $id,
+						'widget_name' => $wp_registered_widgets[ $id ]['name'],
+					)
+				),
+			),
+			(array) $wp_registered_widgets[ $id ]['params']
+		);
+
+		// Substitute HTML `id` and `class` attributes into `before_widget`.
+		$classname_ = '';
+		foreach ( (array) $wp_registered_widgets[ $id ]['classname'] as $cn ) {
+			if ( is_string( $cn ) ) {
+				$classname_ .= '_' . $cn;
+			} elseif ( is_object( $cn ) ) {
+				$classname_ .= '_' . get_class( $cn );
+			}
+		}
+		$classname_ = ltrim( $classname_, '_' );
+
+		$params[0]['before_widget'] = sprintf(
+			$params[0]['before_widget'],
+			str_replace( '\\', '_', $id ),
+			$classname_
+		);
+
+		/**
+		 * Filters the parameters passed to a widget's display callback.
+		 *
+		 * Note: The filter is evaluated on both the front end and back end,
+		 * including for the Inactive Widgets sidebar on the Widgets screen.
+		 *
+		 * @since 2.5.0
+		 *
+		 * @see register_sidebar()
+		 *
+		 * @param array $params {
+		 *     @type array $args  {
+		 *         An array of widget display arguments.
+		 *
+		 *         @type string $name          Name of the sidebar the widget is assigned to.
+		 *         @type string $id            ID of the sidebar the widget is assigned to.
+		 *         @type string $description   The sidebar description.
+		 *         @type string $class         CSS class applied to the sidebar container.
+		 *         @type string $before_widget HTML markup to prepend to each widget in the sidebar.
+		 *         @type string $after_widget  HTML markup to append to each widget in the sidebar.
+		 *         @type string $before_title  HTML markup to prepend to the widget title when displayed.
+		 *         @type string $after_title   HTML markup to append to the widget title when displayed.
+		 *         @type string $widget_id     ID of the widget.
+		 *         @type string $widget_name   Name of the widget.
+		 *     }
+		 *     @type array $widget_args {
+		 *         An array of multi-widget arguments.
+		 *
+		 *         @type int $number Number increment used for multiples of the same widget.
+		 *     }
+		 * }
+		 */
+		$params = apply_filters( 'dynamic_sidebar_params', $params );
+
+		$callback = $wp_registered_widgets[ $id ]['callback'];
+
+		/**
+		 * Fires before a widget's display callback is called.
+		 *
+		 * Note: The action fires on both the front end and back end, including
+		 * for widgets in the Inactive Widgets sidebar on the Widgets screen.
+		 *
+		 * The action is not fired for empty sidebars.
+		 *
+		 * @since 3.0.0
+		 *
+		 * @param array $widget {
+		 *     An associative array of widget arguments.
+		 *
+		 *     @type string   $name        Name of the widget.
+		 *     @type string   $id          Widget ID.
+		 *     @type callable $callback    When the hook is fired on the front end, `$callback` is an array
+		 *                                 containing the widget object. Fired on the back end, `$callback`
+		 *                                 is 'wp_widget_control', see `$_callback`.
+		 *     @type array    $params      An associative array of multi-widget arguments.
+		 *     @type string   $classname   CSS class applied to the widget container.
+		 *     @type string   $description The widget description.
+		 *     @type array    $_callback   When the hook is fired on the back end, `$_callback` is populated
+		 *                                 with an array containing the widget object, see `$callback`.
+		 * }
+		 */
+		do_action( 'dynamic_sidebar', $wp_registered_widgets[ $id ] );
+
+		if ( is_callable( $callback ) ) {
+			call_user_func_array( $callback, $params );
+			$did_one = true;
+		}
+	}
+
+	if ( ! is_admin() && ! empty( $sidebar['after_sidebar'] ) ) {
+		echo $sidebar['after_sidebar'];
+	}
+
+	/**
+	 * Fires after widgets are rendered in a dynamic sidebar.
+	 *
+	 * Note: The action also fires for empty sidebars, and on both the front end
+	 * and back end, including the Inactive Widgets sidebar on the Widgets screen.
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param int|string $index       Index, name, or ID of the dynamic sidebar.
+	 * @param bool       $has_widgets Whether the sidebar is populated with widgets.
+	 *                                Default true.
+	 */
+	do_action( 'dynamic_sidebar_after', $index, true );
+
+	/**
+	 * Filters whether a sidebar has widgets.
+	 *
+	 * Note: The filter is also evaluated for empty sidebars, and on both the front end
+	 * and back end, including the Inactive Widgets sidebar on the Widgets screen.
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param bool       $did_one Whether at least one widget was rendered in the sidebar.
+	 *                            Default false.
+	 * @param int|string $index   Index, name, or ID of the dynamic sidebar.
+	 */
+	return apply_filters( 'dynamic_sidebar_has_widgets', $did_one, $index );
+}
+
+/**
+ * Determines whether a given widget is displayed on the front end.
+ *
+ * Either $callback or $id_base can be used
+ * $id_base is the first argument when extending WP_Widget class
+ * Without the optional $widget_id parameter, returns the ID of the first sidebar
+ * in which the first instance of the widget with the given callback or $id_base is found.
+ * With the $widget_id parameter, returns the ID of the sidebar where
+ * the widget with that callback/$id_base AND that ID is found.
+ *
+ * NOTE: $widget_id and $id_base are the same for single widgets. To be effective
+ * this function has to run after widgets have initialized, at action {@see 'init'} or later.
+ *
+ * For more information on this and similar theme functions, check out
+ * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
+ * Conditional Tags} article in the Theme Developer Handbook.
+ *
+ * @since 2.2.0
+ *
+ * @global array $wp_registered_widgets
+ *
+ * @param callable|false $callback      Optional. Widget callback to check. Default false.
+ * @param string|false   $widget_id     Optional. Widget ID. Optional, but needed for checking.
+ *                                      Default false.
+ * @param string|false   $id_base       Optional. The base ID of a widget created by extending WP_Widget.
+ *                                      Default false.
+ * @param bool           $skip_inactive Optional. Whether to check in 'wp_inactive_widgets'.
+ *                                      Default true.
+ * @return string|false ID of the sidebar in which the widget is active,
+ *                      false if the widget is not active.
+ */
+function is_active_widget( $callback = false, $widget_id = false, $id_base = false, $skip_inactive = true ) {
+	global $wp_registered_widgets;
+
+	$sidebars_widgets = wp_get_sidebars_widgets();
+
+	if ( is_array( $sidebars_widgets ) ) {
+		foreach ( $sidebars_widgets as $sidebar => $widgets ) {
+			if ( $skip_inactive && ( 'wp_inactive_widgets' === $sidebar || str_starts_with( $sidebar, 'orphaned_widgets' ) ) ) {
+				continue;
+			}
+
+			if ( is_array( $widgets ) ) {
+				foreach ( $widgets as $widget ) {
+					if ( ( $callback && isset( $wp_registered_widgets[ $widget ]['callback'] ) && $wp_registered_widgets[ $widget ]['callback'] === $callback ) || ( $id_base && _get_widget_id_base( $widget ) === $id_base ) ) {
+						if ( ! $widget_id || $widget_id === $wp_registered_widgets[ $widget ]['id'] ) {
+							return $sidebar;
+						}
+					}
+				}
+			}
+		}
+	}
+	return false;
+}
+
+/**
+ * Determines whether the dynamic sidebar is enabled and used by the theme.
+ *
+ * For more information on this and similar theme functions, check out
+ * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
+ * Conditional Tags} article in the Theme Developer Handbook.
+ *
+ * @since 2.2.0
+ *
+ * @global array $wp_registered_widgets  Registered widgets.
+ * @global array $wp_registered_sidebars Registered sidebars.
+ *
+ * @return bool True if using widgets, false otherwise.
+ */
+function is_dynamic_sidebar() {
+	global $wp_registered_widgets, $wp_registered_sidebars;
+
+	$sidebars_widgets = get_option( 'sidebars_widgets' );
+
+	foreach ( (array) $wp_registered_sidebars as $index => $sidebar ) {
+		if ( ! empty( $sidebars_widgets[ $index ] ) ) {
+			foreach ( (array) $sidebars_widgets[ $index ] as $widget ) {
+				if ( array_key_exists( $widget, $wp_registered_widgets ) ) {
+					return true;
+				}
+			}
+		}
+	}
+
+	return false;
+}
+
+/**
+ * Determines whether a sidebar contains widgets.
+ *
+ * For more information on this and similar theme functions, check out
+ * the {@link https://developer.wordpress.org/themes/basics/conditional-tags/
+ * Conditional Tags} article in the Theme Developer Handbook.
+ *
+ * @since 2.8.0
+ *
+ * @param string|int $index Sidebar name, id or number to check.
+ * @return bool True if the sidebar has widgets, false otherwise.
+ */
+function is_active_sidebar( $index ) {
+	$index             = ( is_int( $index ) ) ? "sidebar-$index" : sanitize_title( $index );
+	$sidebars_widgets  = wp_get_sidebars_widgets();
+	$is_active_sidebar = ! empty( $sidebars_widgets[ $index ] );
+
+	/**
+	 * Filters whether a dynamic sidebar is considered "active".
+	 *
+	 * @since 3.9.0
+	 *
+	 * @param bool       $is_active_sidebar Whether or not the sidebar should be considered "active".
+	 *                                      In other words, whether the sidebar contains any widgets.
+	 * @param int|string $index             Index, name, or ID of the dynamic sidebar.
+	 */
+	return apply_filters( 'is_active_sidebar', $is_active_sidebar, $index );
+}
+
+//
+// Internal Functions.
+//
+
+/**
+ * Retrieve full list of sidebars and their widget instance IDs.
+ *
+ * Will upgrade sidebar widget list, if needed. Will also save updated list, if
+ * needed.
+ *
+ * @since 2.2.0
+ * @access private
+ *
+ * @global array $_wp_sidebars_widgets
+ * @global array $sidebars_widgets
+ *
+ * @param bool $deprecated Not used (argument deprecated).
+ * @return array Upgraded list of widgets to version 3 array format when called from the admin.
+ */
+function wp_get_sidebars_widgets( $deprecated = true ) {
+	if ( true !== $deprecated ) {
+		_deprecated_argument( __FUNCTION__, '2.8.1' );
+	}
+
+	global $_wp_sidebars_widgets, $sidebars_widgets;
+
+	/*
+	 * If loading from front page, consult $_wp_sidebars_widgets rather than options
+	 * to see if wp_convert_widget_settings() has made manipulations in memory.
+	 */
+	if ( ! is_admin() ) {
+		if ( empty( $_wp_sidebars_widgets ) ) {
+			$_wp_sidebars_widgets = get_option( 'sidebars_widgets', array() );
+		}
+
+		$sidebars_widgets = $_wp_sidebars_widgets;
+	} else {
+		$sidebars_widgets = get_option( 'sidebars_widgets', array() );
+	}
+
+	if ( is_array( $sidebars_widgets ) && isset( $sidebars_widgets['array_version'] ) ) {
+		unset( $sidebars_widgets['array_version'] );
+	}
+
+	/**
+	 * Filters the list of sidebars and their widgets.
+	 *
+	 * @since 2.7.0
+	 *
+	 * @param array $sidebars_widgets An associative array of sidebars and their widgets.
+	 */
+	return apply_filters( 'sidebars_widgets', $sidebars_widgets );
+}
+
+/**
+ * Retrieves the registered sidebar with the given ID.
+ *
+ * @since 5.9.0
+ *
+ * @global array $wp_registered_sidebars The registered sidebars.
+ *
+ * @param string $id The sidebar ID.
+ * @return array|null The discovered sidebar, or null if it is not registered.
+ */
+function wp_get_sidebar( $id ) {
+	global $wp_registered_sidebars;
+
+	foreach ( (array) $wp_registered_sidebars as $sidebar ) {
+		if ( $sidebar['id'] === $id ) {
+			return $sidebar;
+		}
+	}
+
+	if ( 'wp_inactive_widgets' === $id ) {
+		return array(
+			'id'   => 'wp_inactive_widgets',
+			'name' => __( 'Inactive widgets' ),
+		);
+	}
+
+	return null;
+}
+
+/**
+ * Set the sidebar widget option to update sidebars.
+ *
+ * @since 2.2.0
+ * @access private
+ *
+ * @global array $_wp_sidebars_widgets
+ * @param array $sidebars_widgets Sidebar widgets and their settings.
+ */
+function wp_set_sidebars_widgets( $sidebars_widgets ) {
+	global $_wp_sidebars_widgets;
+
+	// Clear cached value used in wp_get_sidebars_widgets().
+	$_wp_sidebars_widgets = null;
+
+	if ( ! isset( $sidebars_widgets['array_version'] ) ) {
+		$sidebars_widgets['array_version'] = 3;
+	}
+
+	update_option( 'sidebars_widgets', $sidebars_widgets );
+}
+
+/**
+ * Retrieve default registered sidebars list.
+ *
+ * @since 2.2.0
+ * @access private
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ *
+ * @return array
+ */
+function wp_get_widget_defaults() {
+	global $wp_registered_sidebars;
+
+	$defaults = array();
+
+	foreach ( (array) $wp_registered_sidebars as $index => $sidebar ) {
+		$defaults[ $index ] = array();
+	}
+
+	return $defaults;
+}
+
+/**
+ * Converts the widget settings from single to multi-widget format.
+ *
+ * @since 2.8.0
+ *
+ * @global array $_wp_sidebars_widgets
+ *
+ * @param string $base_name   Root ID for all widgets of this type.
+ * @param string $option_name Option name for this widget type.
+ * @param array  $settings    The array of widget instance settings.
+ * @return array The array of widget settings converted to multi-widget format.
+ */
+function wp_convert_widget_settings( $base_name, $option_name, $settings ) {
+	// This test may need expanding.
+	$single  = false;
+	$changed = false;
+
+	if ( empty( $settings ) ) {
+		$single = true;
+	} else {
+		foreach ( array_keys( $settings ) as $number ) {
+			if ( 'number' === $number ) {
+				continue;
+			}
+			if ( ! is_numeric( $number ) ) {
+				$single = true;
+				break;
+			}
+		}
+	}
+
+	if ( $single ) {
+		$settings = array( 2 => $settings );
+
+		// If loading from the front page, update sidebar in memory but don't save to options.
+		if ( is_admin() ) {
+			$sidebars_widgets = get_option( 'sidebars_widgets' );
+		} else {
+			if ( empty( $GLOBALS['_wp_sidebars_widgets'] ) ) {
+				$GLOBALS['_wp_sidebars_widgets'] = get_option( 'sidebars_widgets', array() );
+			}
+			$sidebars_widgets = &$GLOBALS['_wp_sidebars_widgets'];
+		}
+
+		foreach ( (array) $sidebars_widgets as $index => $sidebar ) {
+			if ( is_array( $sidebar ) ) {
+				foreach ( $sidebar as $i => $name ) {
+					if ( $base_name === $name ) {
+						$sidebars_widgets[ $index ][ $i ] = "$name-2";
+						$changed                          = true;
+						break 2;
+					}
+				}
+			}
+		}
+
+		if ( is_admin() && $changed ) {
+			update_option( 'sidebars_widgets', $sidebars_widgets );
+		}
+	}
+
+	$settings['_multiwidget'] = 1;
+	if ( is_admin() ) {
+		update_option( $option_name, $settings );
+	}
+
+	return $settings;
+}
+
+/**
+ * Output an arbitrary widget as a template tag.
+ *
+ * @since 2.8.0
+ *
+ * @global WP_Widget_Factory $wp_widget_factory
+ *
+ * @param string $widget   The widget's PHP class name (see class-wp-widget.php).
+ * @param array  $instance Optional. The widget's instance settings. Default empty array.
+ * @param array  $args {
+ *     Optional. Array of arguments to configure the display of the widget.
+ *
+ *     @type string $before_widget HTML content that will be prepended to the widget's HTML output.
+ *                                 Default `<div class="widget %s">`, where `%s` is the widget's class name.
+ *     @type string $after_widget  HTML content that will be appended to the widget's HTML output.
+ *                                 Default `</div>`.
+ *     @type string $before_title  HTML content that will be prepended to the widget's title when displayed.
+ *                                 Default `<h2 class="widgettitle">`.
+ *     @type string $after_title   HTML content that will be appended to the widget's title when displayed.
+ *                                 Default `</h2>`.
+ * }
+ */
+function the_widget( $widget, $instance = array(), $args = array() ) {
+	global $wp_widget_factory;
+
+	if ( ! isset( $wp_widget_factory->widgets[ $widget ] ) ) {
+		_doing_it_wrong(
+			__FUNCTION__,
+			sprintf(
+				/* translators: %s: register_widget() */
+				__( 'Widgets need to be registered using %s, before they can be displayed.' ),
+				'<code>register_widget()</code>'
+			),
+			'4.9.0'
+		);
+		return;
+	}
+
+	$widget_obj = $wp_widget_factory->widgets[ $widget ];
+	if ( ! ( $widget_obj instanceof WP_Widget ) ) {
+		return;
+	}
+
+	$default_args          = array(
+		'before_widget' => '<div class="widget %s">',
+		'after_widget'  => '</div>',
+		'before_title'  => '<h2 class="widgettitle">',
+		'after_title'   => '</h2>',
+	);
+	$args                  = wp_parse_args( $args, $default_args );
+	$args['before_widget'] = sprintf( $args['before_widget'], $widget_obj->widget_options['classname'] );
+
+	$instance = wp_parse_args( $instance );
+
+	/** This filter is documented in wp-includes/class-wp-widget.php */
+	$instance = apply_filters( 'widget_display_callback', $instance, $widget_obj, $args );
+
+	if ( false === $instance ) {
+		return;
+	}
+
+	/**
+	 * Fires before rendering the requested widget.
+	 *
+	 * @since 3.0.0
+	 *
+	 * @param string $widget   The widget's class name.
+	 * @param array  $instance The current widget instance's settings.
+	 * @param array  $args     An array of the widget's sidebar arguments.
+	 */
+	do_action( 'the_widget', $widget, $instance, $args );
+
+	$widget_obj->_set( -1 );
+	$widget_obj->widget( $args, $instance );
+}
+
+/**
+ * Retrieves the widget ID base value.
+ *
+ * @since 2.8.0
+ *
+ * @param string $id Widget ID.
+ * @return string Widget ID base.
+ */
+function _get_widget_id_base( $id ) {
+	return preg_replace( '/-[0-9]+$/', '', $id );
+}
+
+/**
+ * Handle sidebars config after theme change
+ *
+ * @access private
+ * @since 3.3.0
+ *
+ * @global array $sidebars_widgets
+ */
+function _wp_sidebars_changed() {
+	global $sidebars_widgets;
+
+	if ( ! is_array( $sidebars_widgets ) ) {
+		$sidebars_widgets = wp_get_sidebars_widgets();
+	}
+
+	retrieve_widgets( true );
+}
+
+/**
+ * Validates and remaps any "orphaned" widgets to wp_inactive_widgets sidebar,
+ * and saves the widget settings. This has to run at least on each theme change.
+ *
+ * For example, let's say theme A has a "footer" sidebar, and theme B doesn't have one.
+ * After switching from theme A to theme B, all the widgets previously assigned
+ * to the footer would be inaccessible. This function detects this scenario, and
+ * moves all the widgets previously assigned to the footer under wp_inactive_widgets.
+ *
+ * Despite the word "retrieve" in the name, this function actually updates the database
+ * and the global `$sidebars_widgets`. For that reason it should not be run on front end,
+ * unless the `$theme_changed` value is 'customize' (to bypass the database write).
+ *
+ * @since 2.8.0
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ * @global array $sidebars_widgets
+ * @global array $wp_registered_widgets  Registered widgets.
+ *
+ * @param string|bool $theme_changed Whether the theme was changed as a boolean. A value
+ *                                   of 'customize' defers updates for the Customizer.
+ * @return array Updated sidebars widgets.
+ */
+function retrieve_widgets( $theme_changed = false ) {
+	global $wp_registered_sidebars, $sidebars_widgets, $wp_registered_widgets;
+
+	$registered_sidebars_keys = array_keys( $wp_registered_sidebars );
+	$registered_widgets_ids   = array_keys( $wp_registered_widgets );
+
+	if ( ! is_array( get_theme_mod( 'sidebars_widgets' ) ) ) {
+		if ( empty( $sidebars_widgets ) ) {
+			return array();
+		}
+
+		unset( $sidebars_widgets['array_version'] );
+
+		$sidebars_widgets_keys = array_keys( $sidebars_widgets );
+		sort( $sidebars_widgets_keys );
+		sort( $registered_sidebars_keys );
+
+		if ( $sidebars_widgets_keys === $registered_sidebars_keys ) {
+			$sidebars_widgets = _wp_remove_unregistered_widgets( $sidebars_widgets, $registered_widgets_ids );
+
+			return $sidebars_widgets;
+		}
+	}
+
+	// Discard invalid, theme-specific widgets from sidebars.
+	$sidebars_widgets = _wp_remove_unregistered_widgets( $sidebars_widgets, $registered_widgets_ids );
+	$sidebars_widgets = wp_map_sidebars_widgets( $sidebars_widgets );
+
+	// Find hidden/lost multi-widget instances.
+	$shown_widgets = array_merge( ...array_values( $sidebars_widgets ) );
+	$lost_widgets  = array_diff( $registered_widgets_ids, $shown_widgets );
+
+	foreach ( $lost_widgets as $key => $widget_id ) {
+		$number = preg_replace( '/.+?-([0-9]+)$/', '$1', $widget_id );
+
+		// Only keep active and default widgets.
+		if ( is_numeric( $number ) && (int) $number < 2 ) {
+			unset( $lost_widgets[ $key ] );
+		}
+	}
+	$sidebars_widgets['wp_inactive_widgets'] = array_merge( $lost_widgets, (array) $sidebars_widgets['wp_inactive_widgets'] );
+
+	if ( 'customize' !== $theme_changed ) {
+		// Update the widgets settings in the database.
+		wp_set_sidebars_widgets( $sidebars_widgets );
+	}
+
+	return $sidebars_widgets;
+}
+
+/**
+ * Compares a list of sidebars with their widgets against an allowed list.
+ *
+ * @since 4.9.0
+ * @since 4.9.2 Always tries to restore widget assignments from previous data, not just if sidebars needed mapping.
+ *
+ * @param array $existing_sidebars_widgets List of sidebars and their widget instance IDs.
+ * @return array Mapped sidebars widgets.
+ */
+function wp_map_sidebars_widgets( $existing_sidebars_widgets ) {
+	global $wp_registered_sidebars;
+
+	$new_sidebars_widgets = array(
+		'wp_inactive_widgets' => array(),
+	);
+
+	// Short-circuit if there are no sidebars to map.
+	if ( ! is_array( $existing_sidebars_widgets ) || empty( $existing_sidebars_widgets ) ) {
+		return $new_sidebars_widgets;
+	}
+
+	foreach ( $existing_sidebars_widgets as $sidebar => $widgets ) {
+		if ( 'wp_inactive_widgets' === $sidebar || str_starts_with( $sidebar, 'orphaned_widgets' ) ) {
+			$new_sidebars_widgets['wp_inactive_widgets'] = array_merge( $new_sidebars_widgets['wp_inactive_widgets'], (array) $widgets );
+			unset( $existing_sidebars_widgets[ $sidebar ] );
+		}
+	}
+
+	// If old and new theme have just one sidebar, map it and we're done.
+	if ( 1 === count( $existing_sidebars_widgets ) && 1 === count( $wp_registered_sidebars ) ) {
+		$new_sidebars_widgets[ key( $wp_registered_sidebars ) ] = array_pop( $existing_sidebars_widgets );
+
+		return $new_sidebars_widgets;
+	}
+
+	// Map locations with the same slug.
+	$existing_sidebars = array_keys( $existing_sidebars_widgets );
+
+	foreach ( $wp_registered_sidebars as $sidebar => $name ) {
+		if ( in_array( $sidebar, $existing_sidebars, true ) ) {
+			$new_sidebars_widgets[ $sidebar ] = $existing_sidebars_widgets[ $sidebar ];
+			unset( $existing_sidebars_widgets[ $sidebar ] );
+		} elseif ( ! array_key_exists( $sidebar, $new_sidebars_widgets ) ) {
+			$new_sidebars_widgets[ $sidebar ] = array();
+		}
+	}
+
+	// If there are more sidebars, try to map them.
+	if ( ! empty( $existing_sidebars_widgets ) ) {
+
+		/*
+		 * If old and new theme both have sidebars that contain phrases
+		 * from within the same group, make an educated guess and map it.
+		 */
+		$common_slug_groups = array(
+			array( 'sidebar', 'primary', 'main', 'right' ),
+			array( 'second', 'left' ),
+			array( 'sidebar-2', 'footer', 'bottom' ),
+			array( 'header', 'top' ),
+		);
+
+		// Go through each group...
+		foreach ( $common_slug_groups as $slug_group ) {
+
+			// ...and see if any of these slugs...
+			foreach ( $slug_group as $slug ) {
+
+				// ...and any of the new sidebars...
+				foreach ( $wp_registered_sidebars as $new_sidebar => $args ) {
+
+					// ...actually match!
+					if ( false === stripos( $new_sidebar, $slug ) && false === stripos( $slug, $new_sidebar ) ) {
+						continue;
+					}
+
+					// Then see if any of the existing sidebars...
+					foreach ( $existing_sidebars_widgets as $sidebar => $widgets ) {
+
+						// ...and any slug in the same group...
+						foreach ( $slug_group as $slug ) {
+
+							// ... have a match as well.
+							if ( false === stripos( $sidebar, $slug ) && false === stripos( $slug, $sidebar ) ) {
+								continue;
+							}
+
+							// Make sure this sidebar wasn't mapped and removed previously.
+							if ( ! empty( $existing_sidebars_widgets[ $sidebar ] ) ) {
+
+								// We have a match that can be mapped!
+								$new_sidebars_widgets[ $new_sidebar ] = array_merge( $new_sidebars_widgets[ $new_sidebar ], $existing_sidebars_widgets[ $sidebar ] );
+
+								// Remove the mapped sidebar so it can't be mapped again.
+								unset( $existing_sidebars_widgets[ $sidebar ] );
+
+								// Go back and check the next new sidebar.
+								continue 3;
+							}
+						} // End foreach ( $slug_group as $slug ).
+					} // End foreach ( $existing_sidebars_widgets as $sidebar => $widgets ).
+				} // End foreach ( $wp_registered_sidebars as $new_sidebar => $args ).
+			} // End foreach ( $slug_group as $slug ).
+		} // End foreach ( $common_slug_groups as $slug_group ).
+	}
+
+	// Move any left over widgets to inactive sidebar.
+	foreach ( $existing_sidebars_widgets as $widgets ) {
+		if ( is_array( $widgets ) && ! empty( $widgets ) ) {
+			$new_sidebars_widgets['wp_inactive_widgets'] = array_merge( $new_sidebars_widgets['wp_inactive_widgets'], $widgets );
+		}
+	}
+
+	// Sidebars_widgets settings from when this theme was previously active.
+	$old_sidebars_widgets = get_theme_mod( 'sidebars_widgets' );
+	$old_sidebars_widgets = isset( $old_sidebars_widgets['data'] ) ? $old_sidebars_widgets['data'] : false;
+
+	if ( is_array( $old_sidebars_widgets ) ) {
+
+		// Remove empty sidebars, no need to map those.
+		$old_sidebars_widgets = array_filter( $old_sidebars_widgets );
+
+		// Only check sidebars that are empty or have not been mapped to yet.
+		foreach ( $new_sidebars_widgets as $new_sidebar => $new_widgets ) {
+			if ( array_key_exists( $new_sidebar, $old_sidebars_widgets ) && ! empty( $new_widgets ) ) {
+				unset( $old_sidebars_widgets[ $new_sidebar ] );
+			}
+		}
+
+		// Remove orphaned widgets, we're only interested in previously active sidebars.
+		foreach ( $old_sidebars_widgets as $sidebar => $widgets ) {
+			if ( str_starts_with( $sidebar, 'orphaned_widgets' ) ) {
+				unset( $old_sidebars_widgets[ $sidebar ] );
+			}
+		}
+
+		$old_sidebars_widgets = _wp_remove_unregistered_widgets( $old_sidebars_widgets );
+
+		if ( ! empty( $old_sidebars_widgets ) ) {
+
+			// Go through each remaining sidebar...
+			foreach ( $old_sidebars_widgets as $old_sidebar => $old_widgets ) {
+
+				// ...and check every new sidebar...
+				foreach ( $new_sidebars_widgets as $new_sidebar => $new_widgets ) {
+
+					// ...for every widget we're trying to revive.
+					foreach ( $old_widgets as $key => $widget_id ) {
+						$active_key = array_search( $widget_id, $new_widgets, true );
+
+						// If the widget is used elsewhere...
+						if ( false !== $active_key ) {
+
+							// ...and that elsewhere is inactive widgets...
+							if ( 'wp_inactive_widgets' === $new_sidebar ) {
+
+								// ...remove it from there and keep the active version...
+								unset( $new_sidebars_widgets['wp_inactive_widgets'][ $active_key ] );
+							} else {
+
+								// ...otherwise remove it from the old sidebar and keep it in the new one.
+								unset( $old_sidebars_widgets[ $old_sidebar ][ $key ] );
+							}
+						} // End if ( $active_key ).
+					} // End foreach ( $old_widgets as $key => $widget_id ).
+				} // End foreach ( $new_sidebars_widgets as $new_sidebar => $new_widgets ).
+			} // End foreach ( $old_sidebars_widgets as $old_sidebar => $old_widgets ).
+		} // End if ( ! empty( $old_sidebars_widgets ) ).
+
+		// Restore widget settings from when theme was previously active.
+		$new_sidebars_widgets = array_merge( $new_sidebars_widgets, $old_sidebars_widgets );
+	}
+
+	return $new_sidebars_widgets;
+}
+
+/**
+ * Compares a list of sidebars with their widgets against an allowed list.
+ *
+ * @since 4.9.0
+ *
+ * @param array $sidebars_widgets   List of sidebars and their widget instance IDs.
+ * @param array $allowed_widget_ids Optional. List of widget IDs to compare against. Default: Registered widgets.
+ * @return array Sidebars with allowed widgets.
+ */
+function _wp_remove_unregistered_widgets( $sidebars_widgets, $allowed_widget_ids = array() ) {
+	if ( empty( $allowed_widget_ids ) ) {
+		$allowed_widget_ids = array_keys( $GLOBALS['wp_registered_widgets'] );
+	}
+
+	foreach ( $sidebars_widgets as $sidebar => $widgets ) {
+		if ( is_array( $widgets ) ) {
+			$sidebars_widgets[ $sidebar ] = array_intersect( $widgets, $allowed_widget_ids );
+		}
+	}
+
+	return $sidebars_widgets;
+}
+
+/**
+ * Display the RSS entries in a list.
+ *
+ * @since 2.5.0
+ *
+ * @param string|array|object $rss  RSS url.
+ * @param array               $args Widget arguments.
+ */
+function wp_widget_rss_output( $rss, $args = array() ) {
+	if ( is_string( $rss ) ) {
+		$rss = fetch_feed( $rss );
+	} elseif ( is_array( $rss ) && isset( $rss['url'] ) ) {
+		$args = $rss;
+		$rss  = fetch_feed( $rss['url'] );
+	} elseif ( ! is_object( $rss ) ) {
+		return;
+	}
+
+	if ( is_wp_error( $rss ) ) {
+		if ( is_admin() || current_user_can( 'manage_options' ) ) {
+			echo '<p><strong>' . __( 'RSS Error:' ) . '</strong> ' . esc_html( $rss->get_error_message() ) . '</p>';
+		}
+		return;
+	}
+
+	$default_args = array(
+		'show_author'  => 0,
+		'show_date'    => 0,
+		'show_summary' => 0,
+		'items'        => 0,
+	);
+	$args         = wp_parse_args( $args, $default_args );
+
+	$items = (int) $args['items'];
+	if ( $items < 1 || 20 < $items ) {
+		$items = 10;
+	}
+	$show_summary = (int) $args['show_summary'];
+	$show_author  = (int) $args['show_author'];
+	$show_date    = (int) $args['show_date'];
+
+	if ( ! $rss->get_item_quantity() ) {
+		echo '<ul><li>' . __( 'An error has occurred, which probably means the feed is down. Try again later.' ) . '</li></ul>';
+		$rss->__destruct();
+		unset( $rss );
+		return;
+	}
+
+	echo '<ul>';
+	foreach ( $rss->get_items( 0, $items ) as $item ) {
+		$link = $item->get_link();
+		while ( ! empty( $link ) && stristr( $link, 'http' ) !== $link ) {
+			$link = substr( $link, 1 );
+		}
+		$link = esc_url( strip_tags( $link ) );
+
+		$title = esc_html( trim( strip_tags( $item->get_title() ) ) );
+		if ( empty( $title ) ) {
+			$title = __( 'Untitled' );
+		}
+
+		$desc = html_entity_decode( $item->get_description(), ENT_QUOTES, get_option( 'blog_charset' ) );
+		$desc = esc_attr( wp_trim_words( $desc, 55, ' [&hellip;]' ) );
+
+		$summary = '';
+		if ( $show_summary ) {
+			$summary = $desc;
+
+			// Change existing [...] to [&hellip;].
+			if ( str_ends_with( $summary, '[...]' ) ) {
+				$summary = substr( $summary, 0, -5 ) . '[&hellip;]';
+			}
+
+			$summary = '<div class="rssSummary">' . esc_html( $summary ) . '</div>';
+		}
+
+		$date = '';
+		if ( $show_date ) {
+			$date = $item->get_date( 'U' );
+
+			if ( $date ) {
+				$date = ' <span class="rss-date">' . date_i18n( get_option( 'date_format' ), $date ) . '</span>';
+			}
+		}
+
+		$author = '';
+		if ( $show_author ) {
+			$author = $item->get_author();
+			if ( is_object( $author ) ) {
+				$author = $author->get_name();
+				$author = ' <cite>' . esc_html( strip_tags( $author ) ) . '</cite>';
+			}
+		}
+
+		if ( '' === $link ) {
+			echo "<li>$title{$date}{$summary}{$author}</li>";
+		} elseif ( $show_summary ) {
+			echo "<li><a class='rsswidget' href='$link'>$title</a>{$date}{$summary}{$author}</li>";
+		} else {
+			echo "<li><a class='rsswidget' href='$link'>$title</a>{$date}{$author}</li>";
+		}
+	}
+	echo '</ul>';
+	$rss->__destruct();
+	unset( $rss );
+}
+
+/**
+ * Display RSS widget options form.
+ *
+ * The options for what fields are displayed for the RSS form are all booleans
+ * and are as follows: 'url', 'title', 'items', 'show_summary', 'show_author',
+ * 'show_date'.
+ *
+ * @since 2.5.0
+ *
+ * @param array|string $args   Values for input fields.
+ * @param array        $inputs Override default display options.
+ */
+function wp_widget_rss_form( $args, $inputs = null ) {
+	$default_inputs = array(
+		'url'          => true,
+		'title'        => true,
+		'items'        => true,
+		'show_summary' => true,
+		'show_author'  => true,
+		'show_date'    => true,
+	);
+	$inputs         = wp_parse_args( $inputs, $default_inputs );
+
+	$args['title'] = isset( $args['title'] ) ? $args['title'] : '';
+	$args['url']   = isset( $args['url'] ) ? $args['url'] : '';
+	$args['items'] = isset( $args['items'] ) ? (int) $args['items'] : 0;
+
+	if ( $args['items'] < 1 || 20 < $args['items'] ) {
+		$args['items'] = 10;
+	}
+
+	$args['show_summary'] = isset( $args['show_summary'] ) ? (int) $args['show_summary'] : (int) $inputs['show_summary'];
+	$args['show_author']  = isset( $args['show_author'] ) ? (int) $args['show_author'] : (int) $inputs['show_author'];
+	$args['show_date']    = isset( $args['show_date'] ) ? (int) $args['show_date'] : (int) $inputs['show_date'];
+
+	if ( ! empty( $args['error'] ) ) {
+		echo '<p class="widget-error"><strong>' . __( 'RSS Error:' ) . '</strong> ' . esc_html( $args['error'] ) . '</p>';
+	}
+
+	$esc_number = esc_attr( $args['number'] );
+	if ( $inputs['url'] ) :
+		?>
+	<p><label for="rss-url-<?php echo $esc_number; ?>"><?php _e( 'Enter the RSS feed URL here:' ); ?></label>
+	<input class="widefat" id="rss-url-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][url]" type="text" value="<?php echo esc_url( $args['url'] ); ?>" /></p>
+<?php endif; if ( $inputs['title'] ) : ?>
+	<p><label for="rss-title-<?php echo $esc_number; ?>"><?php _e( 'Give the feed a title (optional):' ); ?></label>
+	<input class="widefat" id="rss-title-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][title]" type="text" value="<?php echo esc_attr( $args['title'] ); ?>" /></p>
+<?php endif; if ( $inputs['items'] ) : ?>
+	<p><label for="rss-items-<?php echo $esc_number; ?>"><?php _e( 'How many items would you like to display?' ); ?></label>
+	<select id="rss-items-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][items]">
+	<?php
+	for ( $i = 1; $i <= 20; ++$i ) {
+		echo "<option value='$i' " . selected( $args['items'], $i, false ) . ">$i</option>";
+	}
+	?>
+	</select></p>
+<?php endif; if ( $inputs['show_summary'] || $inputs['show_author'] || $inputs['show_date'] ) : ?>
+	<p>
+	<?php if ( $inputs['show_summary'] ) : ?>
+		<input id="rss-show-summary-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][show_summary]" type="checkbox" value="1" <?php checked( $args['show_summary'] ); ?> />
+		<label for="rss-show-summary-<?php echo $esc_number; ?>"><?php _e( 'Display item content?' ); ?></label><br />
+	<?php endif; if ( $inputs['show_author'] ) : ?>
+		<input id="rss-show-author-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][show_author]" type="checkbox" value="1" <?php checked( $args['show_author'] ); ?> />
+		<label for="rss-show-author-<?php echo $esc_number; ?>"><?php _e( 'Display item author if available?' ); ?></label><br />
+	<?php endif; if ( $inputs['show_date'] ) : ?>
+		<input id="rss-show-date-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][show_date]" type="checkbox" value="1" <?php checked( $args['show_date'] ); ?>/>
+		<label for="rss-show-date-<?php echo $esc_number; ?>"><?php _e( 'Display item date?' ); ?></label><br />
+	<?php endif; ?>
+	</p>
+	<?php
+	endif; // End of display options.
+foreach ( array_keys( $default_inputs ) as $input ) :
+	if ( 'hidden' === $inputs[ $input ] ) :
+		$id = str_replace( '_', '-', $input );
+		?>
+<input type="hidden" id="rss-<?php echo esc_attr( $id ); ?>-<?php echo $esc_number; ?>" name="widget-rss[<?php echo $esc_number; ?>][<?php echo esc_attr( $input ); ?>]" value="<?php echo esc_attr( $args[ $input ] ); ?>" />
+		<?php
+	endif;
+	endforeach;
+}
+
+/**
+ * Process RSS feed widget data and optionally retrieve feed items.
+ *
+ * The feed widget can not have more than 20 items or it will reset back to the
+ * default, which is 10.
+ *
+ * The resulting array has the feed title, feed url, feed link (from channel),
+ * feed items, error (if any), and whether to show summary, author, and date.
+ * All respectively in the order of the array elements.
+ *
+ * @since 2.5.0
+ *
+ * @param array $widget_rss RSS widget feed data. Expects unescaped data.
+ * @param bool  $check_feed Optional. Whether to check feed for errors. Default true.
+ * @return array
+ */
+function wp_widget_rss_process( $widget_rss, $check_feed = true ) {
+	$items = (int) $widget_rss['items'];
+	if ( $items < 1 || 20 < $items ) {
+		$items = 10;
+	}
+	$url          = sanitize_url( strip_tags( $widget_rss['url'] ) );
+	$title        = isset( $widget_rss['title'] ) ? trim( strip_tags( $widget_rss['title'] ) ) : '';
+	$show_summary = isset( $widget_rss['show_summary'] ) ? (int) $widget_rss['show_summary'] : 0;
+	$show_author  = isset( $widget_rss['show_author'] ) ? (int) $widget_rss['show_author'] : 0;
+	$show_date    = isset( $widget_rss['show_date'] ) ? (int) $widget_rss['show_date'] : 0;
+	$error        = false;
+	$link         = '';
+
+	if ( $check_feed ) {
+		$rss = fetch_feed( $url );
+
+		if ( is_wp_error( $rss ) ) {
+			$error = $rss->get_error_message();
+		} else {
+			$link = esc_url( strip_tags( $rss->get_permalink() ) );
+			while ( stristr( $link, 'http' ) !== $link ) {
+				$link = substr( $link, 1 );
+			}
+
+			$rss->__destruct();
+			unset( $rss );
+		}
+	}
+
+	return compact( 'title', 'url', 'link', 'items', 'error', 'show_summary', 'show_author', 'show_date' );
+}
+
+/**
+ * Registers all of the default WordPress widgets on startup.
+ *
+ * Calls {@see 'widgets_init'} action after all of the WordPress widgets have been registered.
+ *
+ * @since 2.2.0
+ */
+function wp_widgets_init() {
+	if ( ! is_blog_installed() ) {
+		return;
+	}
+
+	register_widget( 'WP_Widget_Pages' );
+
+	register_widget( 'WP_Widget_Calendar' );
+
+	register_widget( 'WP_Widget_Archives' );
+
+	if ( get_option( 'link_manager_enabled' ) ) {
+		register_widget( 'WP_Widget_Links' );
+	}
+
+	register_widget( 'WP_Widget_Media_Audio' );
+
+	register_widget( 'WP_Widget_Media_Image' );
+
+	register_widget( 'WP_Widget_Media_Gallery' );
+
+	register_widget( 'WP_Widget_Media_Video' );
+
+	register_widget( 'WP_Widget_Meta' );
+
+	register_widget( 'WP_Widget_Search' );
+
+	register_widget( 'WP_Widget_Text' );
+
+	register_widget( 'WP_Widget_Categories' );
+
+	register_widget( 'WP_Widget_Recent_Posts' );
+
+	register_widget( 'WP_Widget_Recent_Comments' );
+
+	register_widget( 'WP_Widget_RSS' );
+
+	register_widget( 'WP_Widget_Tag_Cloud' );
+
+	register_widget( 'WP_Nav_Menu_Widget' );
+
+	register_widget( 'WP_Widget_Custom_HTML' );
+
+	register_widget( 'WP_Widget_Block' );
+
+	/**
+	 * Fires after all default WordPress widgets have been registered.
+	 *
+	 * @since 2.2.0
+	 */
+	do_action( 'widgets_init' );
+}
+
+/**
+ * Enables the widgets block editor. This is hooked into 'after_setup_theme' so
+ * that the block editor is enabled by default but can be disabled by themes.
+ *
+ * @since 5.8.0
+ *
+ * @access private
+ */
+function wp_setup_widgets_block_editor() {
+	add_theme_support( 'widgets-block-editor' );
+}
+
+/**
+ * Whether or not to use the block editor to manage widgets. Defaults to true
+ * unless a theme has removed support for widgets-block-editor or a plugin has
+ * filtered the return value of this function.
+ *
+ * @since 5.8.0
+ *
+ * @return bool Whether to use the block editor to manage widgets.
+ */
+function wp_use_widgets_block_editor() {
+	/**
+	 * Filters whether to use the block editor to manage widgets.
+	 *
+	 * @since 5.8.0
+	 *
+	 * @param bool $use_widgets_block_editor Whether to use the block editor to manage widgets.
+	 */
+	return apply_filters(
+		'use_widgets_block_editor',
+		get_theme_support( 'widgets-block-editor' )
+	);
+}
+
+/**
+ * Converts a widget ID into its id_base and number components.
+ *
+ * @since 5.8.0
+ *
+ * @param string $id Widget ID.
+ * @return array Array containing a widget's id_base and number components.
+ */
+function wp_parse_widget_id( $id ) {
+	$parsed = array();
+
+	if ( preg_match( '/^(.+)-(\d+)$/', $id, $matches ) ) {
+		$parsed['id_base'] = $matches[1];
+		$parsed['number']  = (int) $matches[2];
+	} else {
+		// Likely an old single widget.
+		$parsed['id_base'] = $id;
+	}
+
+	return $parsed;
+}
+
+/**
+ * Finds the sidebar that a given widget belongs to.
+ *
+ * @since 5.8.0
+ *
+ * @param string $widget_id The widget ID to look for.
+ * @return string|null The found sidebar's ID, or null if it was not found.
+ */
+function wp_find_widgets_sidebar( $widget_id ) {
+	foreach ( wp_get_sidebars_widgets() as $sidebar_id => $widget_ids ) {
+		foreach ( $widget_ids as $maybe_widget_id ) {
+			if ( $maybe_widget_id === $widget_id ) {
+				return (string) $sidebar_id;
+			}
+		}
+	}
+
+	return null;
+}
+
+/**
+ * Assigns a widget to the given sidebar.
+ *
+ * @since 5.8.0
+ *
+ * @param string $widget_id  The widget ID to assign.
+ * @param string $sidebar_id The sidebar ID to assign to. If empty, the widget won't be added to any sidebar.
+ */
+function wp_assign_widget_to_sidebar( $widget_id, $sidebar_id ) {
+	$sidebars = wp_get_sidebars_widgets();
+
+	foreach ( $sidebars as $maybe_sidebar_id => $widgets ) {
+		foreach ( $widgets as $i => $maybe_widget_id ) {
+			if ( $widget_id === $maybe_widget_id && $sidebar_id !== $maybe_sidebar_id ) {
+				unset( $sidebars[ $maybe_sidebar_id ][ $i ] );
+				// We could technically break 2 here, but continue looping in case the ID is duplicated.
+				continue 2;
+			}
+		}
+	}
+
+	if ( $sidebar_id ) {
+		$sidebars[ $sidebar_id ][] = $widget_id;
+	}
+
+	wp_set_sidebars_widgets( $sidebars );
+}
+
+/**
+ * Calls the render callback of a widget and returns the output.
+ *
+ * @since 5.8.0
+ *
+ * @param string $widget_id Widget ID.
+ * @param string $sidebar_id Sidebar ID.
+ * @return string
+ */
+function wp_render_widget( $widget_id, $sidebar_id ) {
+	global $wp_registered_widgets, $wp_registered_sidebars;
+
+	if ( ! isset( $wp_registered_widgets[ $widget_id ] ) ) {
+		return '';
+	}
+
+	if ( isset( $wp_registered_sidebars[ $sidebar_id ] ) ) {
+		$sidebar = $wp_registered_sidebars[ $sidebar_id ];
+	} elseif ( 'wp_inactive_widgets' === $sidebar_id ) {
+		$sidebar = array();
+	} else {
+		return '';
+	}
+
+	$params = array_merge(
+		array(
+			array_merge(
+				$sidebar,
+				array(
+					'widget_id'   => $widget_id,
+					'widget_name' => $wp_registered_widgets[ $widget_id ]['name'],
+				)
+			),
+		),
+		(array) $wp_registered_widgets[ $widget_id ]['params']
+	);
+
+	// Substitute HTML `id` and `class` attributes into `before_widget`.
+	$classname_ = '';
+	foreach ( (array) $wp_registered_widgets[ $widget_id ]['classname'] as $cn ) {
+		if ( is_string( $cn ) ) {
+			$classname_ .= '_' . $cn;
+		} elseif ( is_object( $cn ) ) {
+			$classname_ .= '_' . get_class( $cn );
+		}
+	}
+	$classname_                 = ltrim( $classname_, '_' );
+	$params[0]['before_widget'] = sprintf( $params[0]['before_widget'], $widget_id, $classname_ );
+
+	/** This filter is documented in wp-includes/widgets.php */
+	$params = apply_filters( 'dynamic_sidebar_params', $params );
+
+	$callback = $wp_registered_widgets[ $widget_id ]['callback'];
+
+	ob_start();
+
+	/** This filter is documented in wp-includes/widgets.php */
+	do_action( 'dynamic_sidebar', $wp_registered_widgets[ $widget_id ] );
+
+	if ( is_callable( $callback ) ) {
+		call_user_func_array( $callback, $params );
+	}
+
+	return ob_get_clean();
+}
+
+/**
+ * Calls the control callback of a widget and returns the output.
+ *
+ * @since 5.8.0
+ *
+ * @param string $id Widget ID.
+ * @return string|null
+ */
+function wp_render_widget_control( $id ) {
+	global $wp_registered_widget_controls;
+
+	if ( ! isset( $wp_registered_widget_controls[ $id ]['callback'] ) ) {
+		return null;
+	}
+
+	$callback = $wp_registered_widget_controls[ $id ]['callback'];
+	$params   = $wp_registered_widget_controls[ $id ]['params'];
+
+	ob_start();
+
+	if ( is_callable( $callback ) ) {
+		call_user_func_array( $callback, $params );
+	}
+
+	return ob_get_clean();
+}
+
+/**
+ * Displays a _doing_it_wrong() message for conflicting widget editor scripts.
+ *
+ * The 'wp-editor' script module is exposed as window.wp.editor. This overrides
+ * the legacy TinyMCE editor module which is required by the widgets editor.
+ * Because of that conflict, these two shouldn't be enqueued together.
+ * See https://core.trac.wordpress.org/ticket/53569.
+ *
+ * There is also another conflict related to styles where the block widgets
+ * editor is hidden if a block enqueues 'wp-edit-post' stylesheet.
+ * See https://core.trac.wordpress.org/ticket/53569.
+ *
+ * @since 5.8.0
+ * @access private
+ *
+ * @global WP_Scripts $wp_scripts
+ * @global WP_Styles  $wp_styles
+ */
+function wp_check_widget_editor_deps() {
+	global $wp_scripts, $wp_styles;
+
+	if (
+		$wp_scripts->query( 'wp-edit-widgets', 'enqueued' ) ||
+		$wp_scripts->query( 'wp-customize-widgets', 'enqueued' )
+	) {
+		if ( $wp_scripts->query( 'wp-editor', 'enqueued' ) ) {
+			_doing_it_wrong(
+				'wp_enqueue_script()',
+				sprintf(
+					/* translators: 1: 'wp-editor', 2: 'wp-edit-widgets', 3: 'wp-customize-widgets'. */
+					__( '"%1$s" script should not be enqueued together with the new widgets editor (%2$s or %3$s).' ),
+					'wp-editor',
+					'wp-edit-widgets',
+					'wp-customize-widgets'
+				),
+				'5.8.0'
+			);
+		}
+		if ( $wp_styles->query( 'wp-edit-post', 'enqueued' ) ) {
+			_doing_it_wrong(
+				'wp_enqueue_style()',
+				sprintf(
+					/* translators: 1: 'wp-edit-post', 2: 'wp-edit-widgets', 3: 'wp-customize-widgets'. */
+					__( '"%1$s" style should not be enqueued together with the new widgets editor (%2$s or %3$s).' ),
+					'wp-edit-post',
+					'wp-edit-widgets',
+					'wp-customize-widgets'
+				),
+				'5.8.0'
+			);
+		}
+	}
+}
+
+/**
+ * Registers the previous theme's sidebars for the block themes.
+ *
+ * @since 6.2.0
+ * @access private
+ *
+ * @global array $wp_registered_sidebars Registered sidebars.
+ */
+function _wp_block_theme_register_classic_sidebars() {
+	global $wp_registered_sidebars;
+
+	if ( ! wp_is_block_theme() ) {
+		return;
+	}
+
+	$classic_sidebars = get_theme_mod( 'wp_classic_sidebars' );
+	if ( empty( $classic_sidebars ) ) {
+		return;
+	}
+
+	// Don't use `register_sidebar` since it will enable the `widgets` support for a theme.
+	foreach ( $classic_sidebars as $sidebar ) {
+		$wp_registered_sidebars[ $sidebar['id'] ] = $sidebar;
+	}
+}