Ticket #40951: 40951.5.diff

src/wp-admin/js/widgets/text-widgets.js

@@ -3 +3 @@
 wp.textWidgets = ( function( $ ) {
         'use strict';
 
-        var component = {};
+        var component = {
+                data: {
+                        custom_html_pointer_dismissed: false,
+                        l10n: {
+                                pointer_heading: '',
+                                pointer_text: ''
+                        }
+                }
+        };
 
         /**
          * Text widget control.
@@ -152 +160 @@
                                         if ( restoreTextMode ) {
                                                 switchEditors.go( id, 'toggle' );
                                         }
+
+                                        $( '#' + id + '-html' ).one( 'click', function() {
+                                                var tabContainer;
+                                                if ( component.data.custom_html_pointer_dismissed ) {
+                                                        return;
+                                                }
+                                                tabContainer = $( this ).parent();
+                                                tabContainer.pointer({
+                                                        position: 'bottom',
+                                                        align: 'right',
+                                                        edge: 'right',
+                                                        content: '<h3>' + component.data.l10n.pointer_heading + '</h3><p>' + component.data.l10n.pointer_text + '</p>',
+                                                        close: function() {
+                                                                wp.ajax.post( 'dismiss-wp-pointer', {
+                                                                        pointer: 'text_widget_custom_html'
+                                                                });
+                                                                component.data.custom_html_pointer_dismissed = true;
+                                                        }
+                                                });
+                                                tabContainer.pointer( 'open' );
+                                                tabContainer.pointer( 'widget' ).css( 'z-index', 999999 ); // Default z-index of 9999 is not enough in Customizer.
+                                        });
                                 };
 
                                 if ( editor.initialized ) {
@@ -233 +263 @@
                         return;
                 }
 
+                // Bypass using TinyMCE when widget is in legacy mode.
+                if ( widgetForm.find( '.legacy' ).length > 0 ) {
+                        return;
+                }
+
                 /*
                  * Create a container element for the widget control fields.
                  * This is inserted into the DOM immediately before the the .widget-content
@@ -337 +372 @@
          * When WordPress enqueues this script, it should have an inline script
          * attached which calls wp.textWidgets.init().
          *
+         * @param {object} exports      Server exports.
+         * @param {object} exports.l10n Translations.
          * @returns {void}
          */
-        component.init = function init() {
+        component.init = function init( exports ) {
                 var $document = $( document );
+                component.data = exports;
                 $document.on( 'widget-added', component.handleWidgetAdded );
                 $document.on( 'widget-synced widget-updated', component.handleWidgetUpdated );
 

src/wp-includes/script-loader.php

@@ -608 +608 @@
                 $scripts->add( 'media-audio-widget', "/wp-admin/js/widgets/media-audio-widget$suffix.js", array( 'media-widgets', 'media-audiovideo' ) );
                 $scripts->add( 'media-image-widget', "/wp-admin/js/widgets/media-image-widget$suffix.js", array( 'media-widgets' ) );
                 $scripts->add( 'media-video-widget', "/wp-admin/js/widgets/media-video-widget$suffix.js", array( 'media-widgets', 'media-audiovideo' ) );
-                $scripts->add( 'text-widgets', "/wp-admin/js/widgets/text-widgets$suffix.js", array( 'jquery', 'backbone', 'editor', 'wp-util' ) );
-                $scripts->add_inline_script( 'text-widgets', 'wp.textWidgets.init();', 'after' );
+                $scripts->add( 'text-widgets', "/wp-admin/js/widgets/text-widgets$suffix.js", array( 'jquery', 'backbone', 'editor', 'wp-util', 'wp-pointer' ) );
+                $exports = array(
+                        'custom_html_pointer_dismissed' => is_user_logged_in() && in_array( 'text_widget_custom_html', explode( ',', (string) get_user_meta( get_current_user_id(), 'dismissed_wp_pointers', true ) ) ),
+                        'l10n' => array(
+                                'pointer_heading' => __( 'New Custom HTML Widget' ),
+                                'pointer_text' => __( 'Hey, did you hear we have a "Custom HTML" widget now? Check it out to add some custom code to your site!' ),
+                        ),
+                );
+                $scripts->add_inline_script( 'text-widgets', sprintf( 'wp.textWidgets.init( %s );', wp_json_encode( $exports ) ), 'after' );
 
                 $scripts->add( 'theme', "/wp-admin/js/theme$suffix.js", array( 'wp-backbone', 'wp-a11y' ), false, 1 );
 

src/wp-includes/widgets/class-wp-widget-text.php

@@ -53 +53 @@
         }
 
         /**
+         * Determines whether a given instance is legacy and should bypass using TinyMCE.
+         *
+         * @since 4.8.1
+         *
+         * @param array $instance {
+         *     Instance data.
+         *
+         *     @type string      $text   Content.
+         *     @type bool|string $filter Whether autop or content filters should apply.
+         *     @type bool        $legacy Whether widget is in legacy mode.
+         * }
+         * @return bool Whether Text widget instance contains legacy data.
+         */
+        public function is_legacy_instance( $instance ) {
+
+                // If the widget has been updated while in legacy mode, it stays in legacy mode.
+                if ( ! empty( $instance['legacy'] ) ) {
+                        return true;
+                }
+
+                // If the widget has been added/updated in 4.8 then filter prop is 'content' and it is no longer legacy.
+                if ( isset( $instance['filter'] ) && 'content' === $instance['filter'] ) {
+                        return false;
+                }
+
+                // If the text is empty, then nothing is preventing migration to TinyMCE.
+                if ( empty( $instance['text'] ) ) {
+                        return false;
+                }
+
+                $wpautop = ! empty( $instance['filter'] );
+                $has_line_breaks = ( false !== strpos( $instance['text'], "\n" ) );
+
+                // If auto-paragraphs are not enabled and there are line breaks, then ensure legacy mode.
+                if ( ! $wpautop && $has_line_breaks ) {
+                        return true;
+                }
+
+                /*
+                 * If a shortcode is present (with support added by a plugin), assume legacy mode
+                 * since shortcodes would apply at the widget_text filter and thus be applied
+                 * before wpautop runs at the widget_text_content filter.
+                 */
+                if ( preg_match( '/' . get_shortcode_regex() . '/', $instance['text'] ) ) {
+                        return true;
+                }
+
+                // In the rare case that DOMDocument is not available we cannot reliably sniff content and so we assume legacy.
+                if ( ! class_exists( 'DOMDocument' ) ) {
+                        // @codeCoverageIgnoreStart
+                        return true;
+                        // @codeCoverageIgnoreEnd
+                }
+
+                $doc = new DOMDocument();
+                $doc->loadHTML( sprintf(
+                        '<html><head><meta charset="%s"></head><body>%s</body></html>',
+                        esc_attr( get_bloginfo( 'charset' ) ),
+                        $instance['text']
+                ) );
+                $body = $doc->getElementsByTagName( 'body' )->item( 0 );
+
+                // See $allowedposttags.
+                $safe_elements_attributes = array(
+                        'strong' => array(),
+                        'em' => array(),
+                        'b' => array(),
+                        'i' => array(),
+                        'u' => array(),
+                        's' => array(),
+                        'ul' => array(),
+                        'ol' => array(),
+                        'li' => array(),
+                        'hr' => array(),
+                        'abbr' => array(),
+                        'acronym' => array(),
+                        'code' => array(),
+                        'dfn' => array(),
+                        'a' => array(
+                                'href' => true,
+                        ),
+                        'img' => array(
+                                'src' => true,
+                                'alt' => true,
+                        ),
+                );
+                $safe_empty_elements = array( 'img', 'hr', 'iframe' );
+
+                foreach ( $body->getElementsByTagName( '*' ) as $element ) {
+                        /** @var DOMElement $element */
+                        $tag_name = strtolower( $element->nodeName );
+
+                        // If the element is not safe, then the instance is legacy.
+                        if ( ! isset( $safe_elements_attributes[ $tag_name ] ) ) {
+                                return true;
+                        }
+
+                        // If the element is not safely empty and it has empty contents, then legacy mode.
+                        if ( ! in_array( $tag_name, $safe_empty_elements, true ) && '' === trim( $element->textContent ) ) {
+                                return true;
+                        }
+
+                        // If an attribute is not recognized as safe, then the instance is legacy.
+                        foreach ( $element->attributes as $attribute ) {
+                                /** @var DOMAttr $attribute */
+                                $attribute_name = strtolower( $attribute->nodeName );
+
+                                if ( ! isset( $safe_elements_attributes[ $tag_name ][ $attribute_name ] ) ) {
+                                        return true;
+                                }
+                        }
+                }
+
+                // Otherwise, the text contains no elements/attributes that TinyMCE could drop, and therefore the widget does not need legacy mode.
+                return false;
+        }
+
+        /**
          * Outputs the content for the current Text widget instance.
          *
          * @since 2.8.0
@@ -68 +186 @@
                 $title = apply_filters( 'widget_title', empty( $instance['title'] ) ? '' : $instance['title'], $instance, $this->id_base );
 
                 $text = ! empty( $instance['text'] ) ? $instance['text'] : '';
+                $is_visual_text_widget = ( isset( $instance['filter'] ) && 'content' === $instance['filter'] );
+
+                /*
+                 * Just-in-time temporarily upgrade Visual Text widget shortcode handling
+                 * (with support added by plugin) from the widget_text filter to
+                 * widget_text_content:11 to prevent wpautop from corrupting HTML output
+                 * added by the shortcode.
+                 */
+                $widget_text_do_shortcode_priority = has_filter( 'widget_text', 'do_shortcode' );
+                $should_upgrade_shortcode_handling = ( $is_visual_text_widget && false !== $widget_text_do_shortcode_priority );
+                if ( $should_upgrade_shortcode_handling ) {
+                        remove_filter( 'widget_text', 'do_shortcode', $widget_text_do_shortcode_priority );
+                        add_filter( 'widget_text_content', 'do_shortcode', 11 );
+                }
 
                 /**
                  * Filters the content of the Text widget.
@@ -102 +234 @@
                         }
                 }
 
+                // Undo temporary upgrade of the plugin-supplied shortcode handling.
+                if ( $should_upgrade_shortcode_handling ) {
+                        remove_filter( 'widget_text_content', 'do_shortcode', 11 );
+                        add_filter( 'widget_text', 'do_shortcode', $widget_text_do_shortcode_priority );
+                }
+
                 echo $args['before_widget'];
                 if ( ! empty( $title ) ) {
                         echo $args['before_title'] . $title . $args['after_title'];
@@ -134 +272 @@
                 }
 
                 /*
-                 * Re-use legacy 'filter' (wpautop) property to now indicate content filters will always apply.
+                 * If the Text widget is in legacy mode, then a hidden input will indicate this
+                 * and the new content value for the filter prop will by bypassed. Otherwise,
+                 * re-use legacy 'filter' (wpautop) property to now indicate content filters will always apply.
                  * Prior to 4.8, this is a boolean value used to indicate whether or not wpautop should be
                  * applied. By re-using this property, downgrading WordPress from 4.8 to 4.7 will ensure
                  * that the content for Text widgets created with TinyMCE will continue to get wpautop.
                  */
-                $instance['filter'] = 'content';
+                if ( isset( $new_instance['legacy'] ) || isset( $old_instance['legacy'] ) || ( isset( $new_instance['filter'] ) && 'content' !== $new_instance['filter'] ) ) {
+                        $instance['filter'] = ! empty( $new_instance['filter'] );
+                        $instance['legacy'] = true;
+                } else {
+                        $instance['filter'] = 'content';
+                        unset( $instance['legacy'] );
+                }
 
                 return $instance;
         }
@@ -153 +299 @@
         public function enqueue_admin_scripts() {
                 wp_enqueue_editor();
                 wp_enqueue_script( 'text-widgets' );
+                wp_enqueue_style( 'wp-pointer' );
         }
 
         /**
@@ -160 +307 @@
          *
          * @since 2.8.0
          * @since 4.8.0 Form only contains hidden inputs which are synced with JS template.
+         * @since 4.8.1 Restored original form to be displayed when in legacy mode.
          * @access public
          * @see WP_Widget_Visual_Text::render_control_template_scripts()
          *
@@ -175 +323 @@
                         )
                 );
                 ?>
-                <input id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" class="title" type="hidden" value="<?php echo esc_attr( $instance['title'] ); ?>">
-                <input id="<?php echo $this->get_field_id( 'text' ); ?>" name="<?php echo $this->get_field_name( 'text' ); ?>" class="text" type="hidden" value="<?php echo esc_attr( $instance['text'] ); ?>">
-                <?php
+                <?php if ( ! $this->is_legacy_instance( $instance ) ) : ?>
+                        <input id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" class="title" type="hidden" value="<?php echo esc_attr( $instance['title'] ); ?>">
+                        <input id="<?php echo $this->get_field_id( 'text' ); ?>" name="<?php echo $this->get_field_name( 'text' ); ?>" class="text" type="hidden" value="<?php echo esc_attr( $instance['text'] ); ?>">
+                <?php else : ?>
+                        <input name="<?php echo $this->get_field_name( 'legacy' ); ?>" type="hidden" class="legacy" value="true">
+                        <p>
+                                <label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:' ); ?></label>
+                                <input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $instance['title'] ); ?>"/>
+                        </p>
+                        <div class="notice inline notice-info notice-alt">
+                                <p><?php _e( 'This widget contains code that may work better in the new &#8220;Custom HTML&#8221; widget. How about trying that widget instead?' ); ?></p>
+                        </div>
+                        <p>
+                                <label for="<?php echo $this->get_field_id( 'text' ); ?>"><?php _e( 'Content:' ); ?></label>
+                                <textarea class="widefat" rows="16" cols="20" id="<?php echo $this->get_field_id( 'text' ); ?>" name="<?php echo $this->get_field_name( 'text' ); ?>"><?php echo esc_textarea( $instance['text'] ); ?></textarea>
+                        </p>
+                        <p>
+                                <input id="<?php echo $this->get_field_id( 'filter' ); ?>" name="<?php echo $this->get_field_name( 'filter' ); ?>" type="checkbox"<?php checked( ! empty( $instance['filter'] ) ); ?> />&nbsp;<label for="<?php echo $this->get_field_id( 'filter' ); ?>"><?php _e( 'Automatically add paragraphs' ); ?></label>
+                        </p>
+                <?php endif;
         }
 
         /**

tests/phpunit/tests/widgets/text-widget.php

@@ -40 +40 @@
         }
 
         /**
+         * Test constructor method.
+         *
+         * @covers WP_Widget_Text::__construct
+         */
+        function test_construct() {
+                $widget = new WP_Widget_Text();
+                $this->assertEquals( 'text', $widget->id_base );
+                $this->assertEquals( 'widget_text', $widget->widget_options['classname'] );
+                $this->assertTrue( $widget->widget_options['customize_selective_refresh'] );
+                $this->assertEquals( 400, $widget->control_options['width'] );
+                $this->assertEquals( 350, $widget->control_options['height'] );
+        }
+
+        /**
          * Test enqueue_admin_scripts method.
          *
          * @covers WP_Widget_Text::_register
@@ -122 +136 @@
         }
 
         /**
+         * Example shortcode content to test for wpautop corruption.
+         *
+         * @var string
+         */
+        protected $example_shortcode_content = "<p>One\nTwo\n\nThree</p>\n<script>\ndocument.write('Test1');\n\ndocument.write('Test2');\n</script>";
+
+        /**
+         * Do example shortcode.
+         *
+         * @return string Shortcode content.
+         */
+        function do_example_shortcode() {
+                return $this->example_shortcode_content;
+        }
+
+        /**
+         * Test widget method when a plugin has added shortcode support.
+         *
+         * @covers WP_Widget_Text::widget
+         */
+        function test_widget_shortcodes() {
+                $args = array(
+                        'before_title'  => '<h2>',
+                        'after_title'   => "</h2>\n",
+                        'before_widget' => '<section>',
+                        'after_widget'  => "</section>\n",
+                );
+                $widget = new WP_Widget_Text();
+                add_filter( 'widget_text', 'do_shortcode' );
+                add_shortcode( 'example', array( $this, 'do_example_shortcode' ) );
+
+                $base_instance = array(
+                        'title' => 'Example',
+                        'text' => "This is an example:\n\n[example]",
+                        'filter' => false,
+                );
+
+                // Legacy Text Widget.
+                $instance = array_merge( $base_instance, array(
+                        'filter' => false,
+                ) );
+                ob_start();
+                $widget->widget( $args, $instance );
+                $output = ob_get_clean();
+                $this->assertContains( $this->example_shortcode_content, $output, 'Shortcode was applied without wpautop corrupting it.' );
+                $this->assertEquals( 10, has_filter( 'widget_text', 'do_shortcode' ), 'Filter was restored.' );
+
+                // Visual Text Widget.
+                $instance = array_merge( $base_instance, array(
+                        'filter' => 'content',
+                ) );
+                ob_start();
+                $widget->widget( $args, $instance );
+                $output = ob_get_clean();
+                $this->assertContains( $this->example_shortcode_content, $output, 'Shortcode was applied without wpautop corrupting it.' );
+                $this->assertEquals( 10, has_filter( 'widget_text', 'do_shortcode' ), 'Filter was restored.' );
+                $this->assertFalse( has_filter( 'widget_text_content', 'do_shortcode' ), 'Filter was removed.' );
+
+                // Visual Text Widget with properly-used widget_text_content filter.
+                remove_filter( 'widget_text', 'do_shortcode' );
+                add_filter( 'widget_text_content', 'do_shortcode', 11 );
+                $instance = array_merge( $base_instance, array(
+                        'filter' => 'content',
+                ) );
+                ob_start();
+                $widget->widget( $args, $instance );
+                $output = ob_get_clean();
+                $this->assertContains( $this->example_shortcode_content, $output, 'Shortcode was applied without wpautop corrupting it.' );
+                $this->assertFalse( has_filter( 'widget_text', 'do_shortcode' ), 'Filter was not erroneously restored.' );
+        }
+
+        /**
          * Filters the content of the Text widget.
          *
          * @param string         $widget_text The widget content.
@@ -152 +238 @@
         }
 
         /**
+         * Test is_legacy_instance method.
+         *
+         * @covers WP_Widget_Text::is_legacy_instance
+         */
+        function test_is_legacy_instance() {
+                $widget = new WP_Widget_Text();
+                $base_instance = array(
+                        'title' => 'Title',
+                        'text' => "Hello\n\nWorld",
+                );
+
+                $instance = array_merge( $base_instance, array(
+                        'legacy' => true,
+                ) );
+                $this->assertTrue( $widget->is_legacy_instance( $instance ), 'Legacy when legacy prop is present.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'filter' => 'content',
+                ) );
+                $this->assertFalse( $widget->is_legacy_instance( $instance ), 'Not legacy when filter is explicitly content.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'text' => '',
+                        'filter' => true,
+                ) );
+                $this->assertFalse( $widget->is_legacy_instance( $instance ), 'Not legacy when text is empty.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'text' => "One\nTwo",
+                        'filter' => false,
+                ) );
+                $this->assertTrue( $widget->is_legacy_instance( $instance ), 'Legacy when not-wpautop and there are line breaks.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'text' => "One\n\nTwo",
+                        'filter' => false,
+                ) );
+                $this->assertTrue( $widget->is_legacy_instance( $instance ), 'Legacy when not-wpautop and there are paragraph breaks.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'text' => "One\nTwo",
+                        'filter' => true,
+                ) );
+                $this->assertFalse( $widget->is_legacy_instance( $instance ), 'Not automatically legacy when wpautop and there are line breaks.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'text' => "One\n\nTwo",
+                        'filter' => true,
+                ) );
+                $this->assertFalse( $widget->is_legacy_instance( $instance ), 'Not automatically legacy when wpautop and there are paragraph breaks.' );
+
+                $instance = array_merge( $base_instance, array(
+                        'text' => 'Here is a [gallery]',
+                        'filter' => true,
+                ) );
+                $this->assertTrue( $widget->is_legacy_instance( $instance ), 'Legacy mode when a shortcode is present.' );
+
+                // Check text examples that will not migrate to TinyMCE.
+                $legacy_text_examples = array(
+                        '<span class="hello"></span>',
+                        '<span></span>',
+                        "<ul>\n<li><a href=\"#\" class=\"location\"></a>List Item 1</li>\n<li><a href=\"#\" class=\"location\"></a>List Item 2</li>\n</ul>",
+                        '<a href="#" class="map"></a>',
+                        "<script>\n\\Line one\n\n\\Line two</script>",
+                        "<style>body {\ncolor:red;\n}</style>",
+                        '<span class="fa fa-cc-discover fa-2x" aria-hidden="true"></span>',
+                        "<p>\nStay updated with our latest news and specials. We never sell your information and you can unsubscribe at any time.\n</p>\n\n<div class=\"custom-form-class\">\n\t<form action=\"#\" method=\"post\" name=\"mc-embedded-subscribe-form\">\n\n\t\t<label class=\"screen-reader-text\" for=\"mce-EMAIL-b\">Email </label>\n\t\t<input id=\"mce-EMAIL-b\" class=\"required email\" name=\"EMAIL\" required=\"\" type=\"email\" value=\"\" placeholder=\"Email Address*\" />\n\n\t\t<input class=\"button\" name=\"subscribe\" type=\"submit\" value=\"Go!\" />\n\n\t</form>\n</div>",
+                        '<span class="sectiondown"><a href="#front-page-3"><i class="fa fa-chevron-circle-down"></i></a></span>',
+                );
+                foreach ( $legacy_text_examples as $legacy_text_example ) {
+                        $instance = array_merge( $base_instance, array(
+                                'text' => $legacy_text_example,
+                                'filter' => true,
+                        ) );
+                        $this->assertTrue( $widget->is_legacy_instance( $instance ), 'Legacy when wpautop and there is HTML that is not liable to be mutated.' );
+
+                        $instance = array_merge( $base_instance, array(
+                                'text' => $legacy_text_example,
+                                'filter' => false,
+                        ) );
+                        $this->assertTrue( $widget->is_legacy_instance( $instance ), 'Legacy when not-wpautop and there is HTML that is not liable to be mutated.' );
+                }
+
+                // Check text examples that will migrate to TinyMCE, where elements and attributes are not in whitelist.
+                $migratable_text_examples = array(
+                        'Check out <a href="http://example.com">Example</a>',
+                        '<img src="http://example.com/img.jpg" alt="Img">',
+                        '<strong><em>Hello</em></strong>',
+                        '<b><i><u><s>Hello</s></u></i></b>',
+                        "<ul>\n<li>One</li>\n<li>One</li>\n<li>One</li>\n</ul>",
+                        "<ol>\n<li>One</li>\n<li>One</li>\n<li>One</li>\n</ol>",
+                        "Text\n<hr>\nAddendum",
+                        "Look at this code:\n\n<code>echo 'Hello World!';</code>",
+                );
+                foreach ( $migratable_text_examples as $migratable_text_example ) {
+                        $instance = array_merge( $base_instance, array(
+                                'text' => $migratable_text_example,
+                                'filter' => true,
+                        ) );
+                        $this->assertFalse( $widget->is_legacy_instance( $instance ), 'Legacy when wpautop and there is HTML that is not liable to be mutated.' );
+                }
+        }
+
+        /**
+         * Test update method.
+         *
+         * @covers WP_Widget_Text::form
+         */
+        function test_form() {
+                $widget = new WP_Widget_Text();
+                $instance = array(
+                        'title' => 'Title',
+                        'text' => 'Text',
+                        'filter' => false,
+                        'legacy' => true,
+                );
+                $this->assertTrue( $widget->is_legacy_instance( $instance ) );
+                ob_start();
+                $widget->form( $instance );
+                $form = ob_get_clean();
+                $this->assertContains( 'class="legacy"', $form );
+
+                $instance = array(
+                        'title' => 'Title',
+                        'text' => 'Text',
+                        'filter' => 'content',
+                );
+                $this->assertFalse( $widget->is_legacy_instance( $instance ) );
+                ob_start();
+                $widget->form( $instance );
+                $form = ob_get_clean();
+                $this->assertNotContains( 'class="legacy"', $form );
+        }
+
+        /**
          * Test update method.
          *
          * @covers WP_Widget_Text::update
@@ -161 +382 @@
                 $instance = array(
                         'title' => "The\nTitle",
                         'text'  => "The\n\nText",
-                        'filter' => false,
+                        'filter' => 'content',
                 );
 
                 wp_set_current_user( $this->factory()->user->create( array(
                         'role' => 'administrator',
                 ) ) );
 
-                // Should return valid instance.
+                // Should return valid instance in legacy mode since filter=false and there are line breaks.
                 $expected = array(
                         'title'  => sanitize_text_field( $instance['title'] ),
                         'text'   => $instance['text'],
                         'filter' => 'content',
                 );
                 $result = $widget->update( $instance, array() );
-                $this->assertEquals( $result, $expected );
+                $this->assertEquals( $expected, $result );
                 $this->assertTrue( ! empty( $expected['filter'] ), 'Expected filter prop to be truthy, to handle case where 4.8 is downgraded to 4.7.' );
 
                 // Make sure KSES is applying as expected.
@@ -184 +405 @@
                 $instance['text'] = '<script>alert( "Howdy!" );</script>';
                 $expected['text'] = $instance['text'];
                 $result = $widget->update( $instance, array() );
-                $this->assertEquals( $result, $expected );
+                $this->assertEquals( $expected, $result );
                 remove_filter( 'map_meta_cap', array( $this, 'grant_unfiltered_html_cap' ) );
 
                 add_filter( 'map_meta_cap', array( $this, 'revoke_unfiltered_html_cap' ), 10, 2 );
@@ -192 +413 @@
                 $instance['text'] = '<script>alert( "Howdy!" );</script>';
                 $expected['text'] = wp_kses_post( $instance['text'] );
                 $result = $widget->update( $instance, array() );
-                $this->assertEquals( $result, $expected );
+                $this->assertEquals( $expected, $result );
                 remove_filter( 'map_meta_cap', array( $this, 'revoke_unfiltered_html_cap' ), 10 );
         }
 
         /**
+         * Test update for legacy widgets.
+         *
+         * @covers WP_Widget_Text::update
+         */
+        function test_update_legacy() {
+                $widget = new WP_Widget_Text();
+
+                // Updating a widget with explicit filter=true persists with legacy mode.
+                $instance = array(
+                        'title' => 'Legacy',
+                        'text' => 'Text',
+                        'filter' => true,
+                );
+                $result = $widget->update( $instance, array() );
+                $expected = array_merge( $instance, array(
+                        'legacy' => true,
+                        'filter' => true,
+                ) );
+                $this->assertEquals( $expected, $result );
+
+                // Updating a widget with explicit filter=false persists with legacy mode.
+                $instance['filter'] = false;
+                $result = $widget->update( $instance, array() );
+                $expected = array_merge( $instance, array(
+                        'legacy' => true,
+                        'filter' => false,
+                ) );
+                $this->assertEquals( $expected, $result );
+
+                // Updating a widget in legacy form results in filter=false when checkbox not checked.
+                $instance['filter'] = true;
+                $result = $widget->update( $instance, array() );
+                $expected = array_merge( $instance, array(
+                        'legacy' => true,
+                        'filter' => true,
+                ) );
+                $this->assertEquals( $expected, $result );
+
+                // Updating a widget that previously had legacy form results in filter persisting.
+                unset( $instance['legacy'] );
+                $instance['filter'] = true;
+                $result = $widget->update( $instance, array(
+                        'legacy' => true,
+                ) );
+                $expected = array_merge( $instance, array(
+                        'legacy' => true,
+                        'filter' => true,
+                ) );
+                $this->assertEquals( $expected, $result );
+        }
+
+        /**
          * Grant unfiltered_html cap via map_meta_cap.
          *
          * @param array  $caps    Returns the user's actual capabilities.