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function wp_sanitize_html_kses( $content, $allowed_html, $allowed_protocols = array() ) {
	global $wp_kses_operating_mode;

	$specified_allowed_html = $allowed_html;

	$allowed_protocols = empty( $allowed_protocols )
		? wp_allowed_protocols()
		: $allowed_protocols;

	// Preserve legacy behavior of stripping unwanted C0 control characters.
	$content = preg_replace( '/[\x01-\x08\x0B\x0C\x0E-\x1F]/', '', $content );

	/*
	 * Call legacy pre-kses filters that might have been added by plugins.
	 *
	 * Also set the operating mode to bypass the pre-filters from the legacy
	 * implementation of `wp_kses()`, as these filters are now run in-band
	 * during the processing of the input document.
	 */
	try {
		$previous_kses_mode     = $wp_kses_operating_mode;
		$wp_kses_operating_mode = 'html-api';
		$content                = wp_kses_hook( $content, $specified_allowed_html, $allowed_protocols );
	} finally {
		$wp_kses_operating_mode = $previous_kses_mode;
	}

	$allowed_html = is_array( $allowed_html )
		? $allowed_html
		: wp_kses_allowed_html( $allowed_html );

	/*
	 * The explanation for this call is that “the quoting from `preg_replace(//e)`
	 * requires” it, but this version of `wp_kses()` doesn’t rely on PCRE functions
	 * to parse HTML. Given that this corrupts text, it will be skipped.
	 */
	//$content = wp_kses_stripslashes( $content );

	$processor = new class( $content, $specified_allowed_html, $allowed_html, $allowed_protocols, wp_kses_uri_attributes() ) extends WP_HTML_Tag_Processor {
		/**
		 * An array of allowed HTML elements and attributes, or a context name such as 'post'.
		 *
		 * It’s important to store this alongside the resolved allowable HTML because some
		 * filters in some plugins look for the string values, e.g. for “post” instead of
		 * the resolved array, and apply logic based on that context.
		 *
		 * @see wp_kses_allowed_html() for the list of accepted context names.
		 * @see self::$allowed_html for the resolved array of allowable HTML elements and attributes.
		 *
		 * @since 7.2.0
		 *
		 * @var array[]|string
		 */
		private $specified_allowed_html;

		/**
		 * An array of allowed HTML elements and attributes.
		 *
		 * This array of allowable HTML elements and attributes is resolved from the value provided
		 * to the sanitizer function. It’s resolved at the start to avoid repeatedly calling the
		 * filter stack and array-merging computations. However, it’s still necessary to carry along
		 * the provided context so that filters expecting the array-or-string version continue to
		 * operate properly.
		 *
		 * @see self::$specified_allowed_html
		 *
		 * @since 7.2.0
		 *
		 * @var array[]
		 */
		private $allowed_html;

		/**
		 * Array of allowed URL protocols.
		 *
		 * @see \wp_allowed_protocols()
		 *
		 * @since 7.2.0
		 *
		 * @var string[]
		 */
		private $allowed_protocols;

		/**
		 * List of attributes whose values are expected to be considered URLs.
		 *
		 * @see \wp_kses_uri_attributes()
		 *
		 * @since 7.2.0
		 *
		 * @var string[]
		 */
		private $uri_attributes;

		/**
		 * Tracks balanced tags when inside foreign content.
		 *
		 * @since 7.2.0
		 *
		 * @var string[]
		 */
		private $foreign_content_stack = array();

		/**
		 * Tracks how deeply into a MathML ANNOTATION-XML element the current token is;
		 * an optimization to avoid checking up the open-element stack on every token.
		 *
		 * @since 7.2.0
		 *
		 * @var int
		 */
		private $math_annotation_xml_depth = 0;

		/**
		 * Constructor function, used internally.
		 *
		 * @since 7.2.0
		 * @access private
		 *
		 * @param string         $html                   Content to filter.
		 * @param array[]|string $specified_allowed_html Context passed into sanitizer.
		 * @param array[]        $allowed_html           Resolved allowable HTML.
		 * @param string[]       $allowed_protocols      Resolved allowable protocols.
		 * @param string[]       $uri_attributes         Resolved URI attributes.
		 */
		public function __construct( $html, $specified_allowed_html, $allowed_html, $allowed_protocols, $uri_attributes ) {
			parent::__construct( $html );

			$this->specified_allowed_html = $specified_allowed_html;
			$this->allowed_html           = $allowed_html;
			$this->allowed_protocols      = $allowed_protocols;
			$this->uri_attributes         = $uri_attributes;
		}

		/**
		 * Returns the raw byte-span of the currently-matched token,
		 * assuming that the parser is matched on a token.
		 *
		 * @since 7.2.0
		 * @access private
		 *
		 * @return WP_HTML_Span|null
		 */
		private function get_span() {
			$this->set_bookmark( 'here' );

			if ( ! isset( $this->bookmarks['here'] ) ) {
				return null;
			}

			return $this->bookmarks['here'];
		}

		/**
		 * Sets the value of a given HTML attribute, adjusting URL attributes
		 * to ensure compatibility with legacy {@see wp_kses()} behavior.
		 *
		 * @since 7.2.0
		 * @access private
		 *
		 * @param string      $name  Name of HTML attribute to set.
		 * @param string|true $value Value to set; `true` for boolean attribute.
		 * @return bool Whether the attribute was set.
		 */
		public function set_attribute( $name, $value ): bool {
			$lower_name = strtolower( $name );
			$is_url_ish = in_array( $lower_name, $this->uri_attributes, true );

			if ( ! $is_url_ish || ! is_string( $value ) ) {
				return parent::set_attribute( $name, $value );
			}

			$escaped = strtr(
				$value,
				array(
					'<' => '&lt;',
					'>' => '&gt;',
					'&' => '&amp;',
					'"' => '&quot;',
					"'" => '&apos;',
				)
			);

			// Set a benign placeholder to replace below.
			if ( ! parent::set_attribute( $name, true ) ) {
				return false;
			}

			$this->lexical_updates[ $lower_name ]->text = " {$lower_name}=\"{$escaped}\"";

			return true;
		}

		/**
		 * Indicates if the currently-matched token, given the parsed context, would require more
		 * complicated parsing rules to proceed without risking escape from foreign content.
		 *
		 * @since 7.2.0
		 * @access private
		 *
		 * @param bool $is_inside_mathml_text_integration_point
		 * @param bool $is_inside_svg_html_integration_point
		 * @return bool
		 */
		private function could_escape_foreign_content( bool $is_inside_mathml_text_integration_point, bool $is_inside_svg_html_integration_point ): bool {
			$token_name   = $this->get_token_name();
			$is_closer    = $this->is_tag_closer();
			$namespace    = $this->get_namespace();
			$self_closing = ! $is_closer && $this->has_self_closing_flag();

			if ( ! $is_closer && $is_inside_svg_html_integration_point ) {
				return true;
			}

			/*
			 * These two elements are excepted in HTML from the normal processing
			 * rules because they function in similar ways to character data.
			 *
			 * > The mglyph element is used to represent non-standard characters or
			 * > symbols by images; the malignmark element establishes an alignment
			 * > point for use within table constructs, and is otherwise invisible.
			 *
			 * They must contain no elements, so only allow self-closing tags.
			 */
			if ( ! $is_closer && $is_inside_mathml_text_integration_point ) {
				return ! ( $self_closing && ( 'MGLYPH' === $token_name || 'MALIGNMARK' === $token_name ) );
			}

			if (
				! $is_closer &&
				'FONT' === $token_name &&
				(
					null !== $this->get_attribute( 'color' ) ||
					null !== $this->get_attribute( 'face' ) ||
					null !== $this->get_attribute( 'size' )
				)
			) {
				return true;
			}

			if (
				! $is_closer &&
				in_array(
					$token_name,
					array(
						'B',
						'BIG',
						'BLOCKQUOTE',
						'BODY',
						'BR',
						'CENTER',
						'CODE',
						'DD',
						'DIV',
						'DL',
						'DT',
						'EM',
						'EMBED',
						'H1',
						'H2',
						'H3',
						'H4',
						'H5',
						'H6',
						'HEAD',
						'HR',
						'I',
						'IMG',
						'LI',
						'LISTING',
						'MENU',
						'META',
						'NOBR',
						'OL',
						'P',
						'PRE',
						'RUBY',
						'S',
						'SMALL',
						'SPAN',
						'STRONG',
						'STRIKE',
						'SUB',
						'SUP',
						'TABLE',
						'TT',
						'U',
						'UL',
						'VAR',
					),
					true
				) ||
				(
					$is_closer &&
					in_array(
						$token_name,
						array(
							'BR',
							'P',
						),
						true
					)
				)
			) {
				return true;
			}

			if ( 'math' === $namespace && ! $is_closer && ! $self_closing ) {
				$encoding = $this->get_attribute( 'encoding' );
				if (
					'ANNOTATION-XML' === $token_name &&
					is_string( $encoding ) &&
					(
						0 === strcasecmp( $encoding, 'text/html' ) ||
						0 === strcasecmp( $encoding, 'application/xhtml+xml' )
					)
				) {
					return true;
				}

				/*
				 * When SVG becomes a direct descendant of a MathML ANNOTATION-XML,
				 * the namespace remains `math` but there could be an SVG element
				 * with an HTML integration point. Conservatively reject any child
				 * SVG element inside a MathML ANNOTATION-XML to prevent this.
				 */
				if ( 'SVG' === $token_name && $this->math_annotation_xml_depth > 0 ) {
					return true;
				}
			}

			return false;
		}

		/**
		 * Indicates if a given string contains text that would parse as a block delimiter.
		 *
		 * @since 7.2.0
		 * @access private
		 *
		 * @param string $text Does a block comment delimiter exist in this string value?
		 * @return bool Whether a block comment delimiter of any kind was found in the given string.
		 */
		private static function contains_a_block_delimiter( string $text ): bool {
			if ( '' === $text ) {
				return false;
			}

			$processor = new WP_Block_Processor( $text );

			return $processor->next_delimiter();
		}

		/**
		 * Returns a sanitized copy of the input HTML.
		 *
		 * @since 7.2.0
		 * @access private
		 *
		 * @return string Sanitized copy of given input HTML.
		 */
		public function sanitize() {
			$template_depth            = 0;
			$output                    = '';
			$special_newline_at        = PHP_INT_MIN;
			$foreign_content_starts_at = PHP_INT_MAX;
			$open_blocks               = array();
			$open_blocks_at            = array();
			$foreign_closed_blocks     = array();

			$is_in_mathml_text_integration_point = false;
			$is_in_svg_html_integration_point    = false;

			/**
			 * These are treated as void elements inside the HTML API
			 * due to the special handling of their inner text content.
			 */
			$special_atomic_elements = array(
				'IFRAME',
				'NOEMBED',
				'NOFRAMES',
				'SCRIPT',
				'STYLE',
				'TEXTAREA',
				'TITLE',
				'XMP',
			);

			while ( $this->next_token() ) {
				$token_name = $this->get_token_name();
				$token_type = $this->get_token_type();
				$namespace  = $this->get_namespace();
				$is_closer  = $this->is_tag_closer();
				$here       = $this->get_span();

				/*
				 * Prevent allowing NOSCRIPT elements whose parsing rules change
				 * based on whether the scripting flag is enabled in a browser.
				 * Rely on trusted inputs for producing the appropriate NOSCRIPT
				 * content, and prevent untrusted inputs from generating it.
				 */
				if ( 'NOSCRIPT' === $token_name && ! $is_closer ) {
					break;
				}

				/*
				 * PLAINTEXT is unique in that it changes the tokenization. Everything in
				 * a document following the PLAINTEXT opening tag is interpreted as character
				 * data, meaning there are no more tags, comments, or anything. Because of
				 * this, it is the only element without a closing tag.
				 *
				 * Because of its unique role, it’s risky to leave in place because very few
				 * parsers are going to recognize the tag and properly switch modes for the
				 * rest of the document. Instead, the PLAINTEXT tag is removed and its content
				 * is re-written as an escaped text node.
				 *
				 * This changes the structure of the document, because no PLAINTEXT element
				 * will appear, and it won’t be possible to style its contents, but the element
				 * is discouraged anyway and should not be allowed from untrusted inputs.
				 */
				if ( 'PLAINTEXT' === $token_name && 'html' === $namespace && ! $is_closer ) {
					if ( $template_depth > 0 && ! isset( $this->allowed_html['template'] ) ) {
						break;
					}

					$text = substr( $this->html, $here->start + $here->length );

					$needs_special_newline = (
						strlen( $output ) === $special_newline_at &&
						1 === strspn( $text, "\n\r", 0, 1 )
					);

					if ( $needs_special_newline ) {
						$output .= "\n";
					}

					$output .= strtr(
						$text,
						array(
							"\x00" => "\u{FFFD}",
							"\r\n" => "\n",
							"\r"   => "\n",
							'<'    => '&lt;',
							'&'    => '&amp;',
							'>'    => '&gt;',
						)
					);

					break;
				}

				$is_in_text_integration_point = (
					$is_in_mathml_text_integration_point ||
					( ! $is_closer && $is_in_svg_html_integration_point )
				);

				/*
				 * While content inside integration points is generally not allowed here,
				 * character data inside the MathML text elements _is_ allowed. This is
				 * because the rules only change slightly: NULL bytes are removed instead
				 * of being replaced with the Unicode replacement character U+FFFD; and
				 * active formats are reconstructed. The format reconstruction doesn’t
				 * occur here but a browser will still do so; this sanitizer is generally
				 * unaware of nesting structure.
				 */
				if ( $is_in_text_integration_point && '#text' === $token_type ) {
					$this->change_parsing_namespace( 'html' );
					$text = $this->get_modifiable_text();
					$this->change_parsing_namespace( $namespace );
				} else {
					$text = $this->get_modifiable_text();
				}

				/*
				 * Enter the foreign content and change the parsing namespace
				 * so that the parser recognizes real self-closing elements.
				 */
				$is_svg_or_math        = 'MATH' === $token_name || 'SVG' === $token_name;
				$has_self_closing_flag = ! $is_closer && $this->has_self_closing_flag();
				if ( $is_svg_or_math && ! $is_closer && 'html' === $namespace ) {
					$this->change_parsing_namespace( strtolower( $token_name ) );
					$namespace = $this->get_namespace();
				}

				if ( 'html' !== $namespace && '#tag' === $token_type ) {
					/*
					 * Ensure that only well-formed foreign content is allowed.
					 * Since un-balanced closing tags might implicitly close the
					 * open foreign-content element, these must be rejected.
					 */
					if ( $is_closer ) {
						$open_element = array_pop( $this->foreign_content_stack );
						if ( null === $open_element || $token_name !== $open_element ) {
							break;
						}

						if ( 'math' === $namespace && 'ANNOTATION-XML' === $open_element ) {
							--$this->math_annotation_xml_depth;
						}

						/*
						 * Reset the foreign content tracker so it doesn’t truncate
						 * unintentionally after foreign content has properly closed.
						 */
						if ( empty( $this->foreign_content_stack ) ) {
							$foreign_content_starts_at = PHP_INT_MAX;
						}
					} else {
						/*
						 * Track the opening of the last transition into foreign
						 * content so that it can be discarded when encountering
						 * tags that would require more substantial parsing.
						 */
						if ( empty( $this->foreign_content_stack ) ) {
							$foreign_content_starts_at = strlen( $output );
						}

						$this->foreign_content_stack[] = $token_name;

						if ( 'math' === $namespace && 'ANNOTATION-XML' === $token_name ) {
							++$this->math_annotation_xml_depth;
						}
					}
				}

				if ( 'TEMPLATE' === $token_name && 'html' === $namespace && ! $is_closer ) {
					++$template_depth;
				}

				$skip_token = (
					(
						$template_depth > 0 &&
						! isset( $this->allowed_html['template'] )
					) ||
					(
						! empty( $this->foreign_content_stack ) &&
						! isset( $this->allowed_html[ strtolower( $this->foreign_content_stack[0] ) ] )
					)
				);

				switch ( $token_type ) {
					case '#text':
						if ( $skip_token ) {
							break;
						}

						$needs_special_newline = (
							strlen( $output ) === $special_newline_at &&
							1 === strspn( $text, "\n\r", 0, 1 )
						);

						$text = strtr(
							$text,
							array(
								"\r" => '&#xD;',
								'<'  => '&lt;',
								'&'  => '&amp;',
								'>'  => '&gt;',
							)
						);

						if ( $needs_special_newline ) {
							$output .= "\n{$text}";
						} else {
							$output .= $text;
						}
						break;

					/*
					 * Untrusted sources should not be creating these kinds of tokens,
					 * so remove them entirely from the output.
					 */
					case '#doctype':
					case '#presumptuous-tag':
					case '#processing-instruction':
						break;

					/*
					 * It’s questionable whether these should be allowed through, but
					 * the legacy behavior supports it. Therefore, allow them as long
					 * as they don’t contain potentially confusing syntax characters.
					 */
					case '#funky-comment':
						if ( ! $skip_token && ! str_contains( $text, '<' ) ) {
							$output .= substr( $this->html, $here->start, $here->length );
						}
						break;

					/*
					 * `wp_kses()` runs iteratively on the content inside of these tokens,
					 * but the content is benign in a browser.
					 */
					case '#comment':
						if ( $skip_token ) {
							break;
						}

						/*
						 * There are several kinds of malformed HTML which are handled by interpreting
						 * them as HTML comments. For example, `<?>` is called a “bogus comment” by the
						 * HTML specification, but when loaded by a browser is equivalent to `<!--?-->`.
						 * In this way, interacting with the DOM via JavaScript differs from handling
						 * the textual representation of a page in PHP.
						 *
						 * Ignore these non-normative comment forms to protect downstream parsers which
						 * might not be expecting their kinds of syntax. This prevents mis-parses for
						 * code which over-simplifies HTML parsing.
						 */
						if ( WP_HTML_Tag_Processor::COMMENT_AS_HTML_COMMENT !== $this->get_comment_type() ) {
							break;
						}

						// Apply special filtering for block comment delimiters with JSON attributes.
						$comment = substr( $this->html, $here->start, $here->length );

						/*
						 * A comment like `<!-- notes --!>` still appears as a normative HTML comment,
						 * but as an incorrectly-closed comment. Ignore these as well, as part of only
						 * allowing normative comment contents.
						 */
						$was_incorrectly_closed = '!' === $comment[ strlen( $comment ) - 2 ];
						if ( $was_incorrectly_closed ) {
							break;
						}

						$block_processor = new WP_Block_Processor( $comment );
						if ( $block_processor->next_token() && ! $block_processor->is_html() ) {
							$block_type          = $block_processor->get_block_type();
							$implicit_block_type = str_starts_with( $block_type, 'core/' )
								? substr( $block_type, /* 'core/' */ 5 )
								: $block_type;

							switch ( $block_processor->get_delimiter_type() ) {
								// Track when blocks open and when they don’t self-close.
								case WP_Block_Processor::OPENER:
									$open_blocks[]    = $implicit_block_type;
									$open_blocks_at[] = strlen( $output );
									break;

								// Track when blocks close.
								case WP_Block_Processor::CLOSER:
									if ( empty( $open_blocks ) ) {
										break 2;
									}

									/*
									 * The default parser closes any open block, even when
									 * the names don’t match. Preserve this behavior here
									 * to avoid differences in sanitization and parsing.
									 */
									$closed_block    = array_pop( $open_blocks );
									$closed_block_at = array_pop( $open_blocks_at );

									if ( 'html' !== $namespace && $closed_block_at < $foreign_content_starts_at ) {
										$foreign_closed_blocks[] = $closed_block;
									}
							}

							// Filter block attributes for opening delimiters.
							$attributes = $block_processor->allocate_and_return_parsed_attributes();
							$voider     = WP_Block_Processor::VOID === $block_processor->get_delimiter_type() ? '/' : '';
							if ( $block_processor->opens_block() ) {
								if ( isset( $attributes ) ) {
									$attributes = filter_block_kses_value(
										$attributes,
										$this->specified_allowed_html,
										$this->allowed_protocols,
										array( 'blockName' => $block_type )
									);
								}
							}

							// Fully normalize all block delimiters: name, whitespace, attributes, flags.
							if ( WP_Block_Processor::CLOSER === $block_processor->get_delimiter_type() ) {
								$text = " /wp:{$implicit_block_type} ";
							} elseif ( ! empty( $attributes ) ) {
								$serialized_attributes = serialize_block_attributes( $attributes );

								$text = " wp:{$implicit_block_type} {$serialized_attributes} {$voider}";
							} else {
								$text = " wp:{$implicit_block_type} {$voider}";
							}
						}

						/*
						 * Legacy `wp_kses()` recursively calls itself on the contents of comments.
						 * Since comment content is not escaped, this changes the meaning of those
						 * comments when parsed. Still, code often expects to find tag-like syntax
						 * only when they are real tags. This legacy defect is preserved to avoid
						 * presenting content that downstream parsers might misinterpret as markup.
						 */
						$text = strtr( $text, array( '<' => '&lt;' ) );

						$output .= "<!--{$text}-->";
						break;

					/*
					 * True CDATA sections only exist within embedded SVG and MathML content,
					 * where they represent text data without any escaping. However, because
					 * parsers tend to vary on how to parse these, for untrusted inputs,
					 * rewrite all CDATA sections as normal escaped text.
					 */
					case '#cdata-section':
						if ( ! $skip_token ) {
							$output .= strtr(
								$text,
								array(
									"\x00" => "\u{FFFD}",
									'<'    => '&lt;',
									'&'    => '&amp;',
									'>'    => '&gt;',
								)
							);
						}

						break;

					case '#tag':
						/*
						 * Any failures inside foreign content should return the part of
						 * the post processed up until the entrance of the foreign content.
						 * This is necessary because it’s only inside foreign content that
						 * the self-closing flag indicates a self-closing element.
						 *
						 * While the HTML Processor can enter into SVG and MATH and track
						 * when they close, it’s substantially more complicated and requires
						 * considerable accounting. To avoid all of that, and to accept the
						 * kind of content that is nominal and safe, track only when the
						 * next tag _could_ lead to implicit changing of the parsing namespace
						 * or insertion mode.
						 */
						if (
							'html' !== $namespace &&
							$this->could_escape_foreign_content(
								$is_in_mathml_text_integration_point,
								$is_in_svg_html_integration_point
							)
						) {
							break 2;
						}

						if ( $skip_token ) {
							break;
						}

						$tag_name = strtolower( $token_name );

						// Skip unallowed elements by tag name
						if ( ! isset( $this->allowed_html[ $tag_name ] ) ) {
							break;
						}

						if ( $is_closer ) {
							$output .= "</{$tag_name}>";
							break;
						}

						$is_special_atomic_element = (
							'html' === $namespace &&
							in_array( $token_name, $special_atomic_elements, true )
						);

						$expects_closer = ! (
							'html' === $namespace
								? ( WP_HTML_Processor::is_void( $token_name ) || $is_special_atomic_element )
								: $has_self_closing_flag
						);

						$self_closer = ( 'html' !== $namespace && $has_self_closing_flag ) ? ' /' : '';
						$closing_tag = $is_special_atomic_element ? "</{$tag_name}>" : '';

						$attribute_names    = $this->get_attribute_names_with_prefix( '' );
						$element_attributes = $this->allowed_html[ $tag_name ];

						// Check for required attributes.
						$required_attributes = array();
						if ( is_array( $element_attributes ) ) {
							foreach ( $element_attributes as $name => $spec ) {
								if ( true === ( $spec['required'] ?? false ) ) {
									$required_attributes[ $name ] = true;
								}
							}
						}

						/*
						 * Allow `data-*` attributes.
						 *
						 * When specifying `$allowed_html`, the attribute name should be set as
						 * `data-*` (not to be mixed with the HTML 4.0 `data` attribute, see
						 * https://www.w3.org/TR/html40/struct/objects.html#adef-data).
						 *
						 * Note: the attribute name should only contain `A-Za-z0-9_-` chars.
						 */
						if ( ! empty( $element_attributes['data-*'] ) ) {
							if ( is_array( $attribute_names ) ) {
								foreach ( $attribute_names as $name ) {
									if (
										1 === preg_match( '/^data-[a-z0-9_-]+$/', $name ) &&
										(
											! isset( $element_attributes[ $name ] ) ||
											'' === $element_attributes[ $name ]
										)
									) {
										$element_attributes[ $name ] = $element_attributes['data-*'];
									}
								}
							}

							unset( $element_attributes['data-*'] );
						}

						$tag_maker = new self(
							"<{$tag_name}{$self_closer}>{$closing_tag}",
							$this->specified_allowed_html,
							$this->allowed_html,
							$this->allowed_protocols,
							$this->uri_attributes
						);
						$tag_maker->change_parsing_namespace( $namespace );
						$tag_maker->next_token();
						if ( is_array( $attribute_names ) ) {
							foreach ( $attribute_names as $name ) {
								$spec = $element_attributes[ $name ] ?? null;

								// This attribute is not specified, thus not allowed. Skip it.
								if ( null === $spec || '' === $spec ) {
									continue;
								}

								$raw_value = $this->get_attribute( $name );
								$value     = is_string( $raw_value ) ? $raw_value : '';

								// Process the style attribute through CSS sanitization.
								if ( 'style' === $name ) {
									if ( ! is_string( $raw_value ) ) {
										continue;
									}

									$value = safecss_filter_attr( $value );
									if ( '' === trim( $value ) ) {
										continue;
									}
								}

								$is_url_ish = in_array( strtolower( $name ), $this->uri_attributes, true );
								if ( $is_url_ish ) {
									$value = wp_kses_bad_protocol( $value, $this->allowed_protocols );
								}

								/*
								 * Process the remaining attributes according to their policies.
								 *
								 * Non-array values for the attribute specification are assumed
								 * to be `true`, thus permitting the attribute.
								 */
								if ( is_array( $spec ) ) {
									foreach ( $spec as $property => $constraint ) {
										$vless = true === $raw_value ? 'y' : 'n';

										if ( ! wp_kses_check_attr_val( $value, $vless, $property, $constraint ) ) {
											continue 2;
										}
									}
								}

								$did_set = ( true === $raw_value && '' === $value )
									? $tag_maker->set_attribute( $name, true )
									: $tag_maker->set_attribute( $name, $value );

								if ( $did_set ) {
									unset( $required_attributes[ $name ] );
								}
							}
						}

						$needs_special_newline = 'html' === $namespace && ( 'PRE' === $token_name || 'LISTING' === $token_name );

						if ( ! empty( $required_attributes ) ) {
							if ( ! $expects_closer ) {
								break;
							}

							/*
							 * Since this processor cannot track nesting of HTML elements
							 * generally, leave opening tags when required attributes are
							 * missing, but strip them of their attributes.
							 */
							$output .= "<{$tag_name}>";
							if ( $needs_special_newline ) {
								$special_newline_at = strlen( $output );
							}
							break;
						}

						if ( $is_special_atomic_element ) {
							if ( 'TITLE' === $token_name || 'TEXTAREA' === $token_name ) {
								/*
								 * RCDATA nodes can be safely escaped, but this must be
								 * done after enqueing the update to avoid double-escaping.
								 */
								$tag_maker->set_modifiable_text( $text );
								$tag_maker->lexical_updates['modifiable text']->text = strtr(
									$tag_maker->lexical_updates['modifiable text']->text,
									array(
										"\x00" => "\u{FFFD}",
										"\r"   => '&#xD;',
									)
								);
							} elseif ( ! self::contains_a_block_delimiter( $text ) ) {
								// Other nodes not containing a block delimiter are safe.
								$tag_maker->set_modifiable_text( $text );
							} else {
								/*
								 * But RAWTEXT and SCRIPT cannot be generally escaped, so reject
								 * updates which would include something that could be misparsed
								 * as a block comment delimiter.
								 */
								$tag_maker->set_modifiable_text( '' );
							}
						}

						$output .= $tag_maker->get_updated_html();
						if ( $needs_special_newline ) {
							$special_newline_at = strlen( $output );
						}

						break;
				}

				// Re-enter the HTML namespace.
				if ( 'html' !== $namespace ) {
					if ( $has_self_closing_flag ) {
						array_pop( $this->foreign_content_stack );

						if ( 'math' === $namespace && 'ANNOTATION-XML' === $token_name ) {
							--$this->math_annotation_xml_depth;
						}
					}

					if ( empty( $this->foreign_content_stack ) ) {
						$is_in_mathml_text_integration_point = false;
						$is_in_svg_html_integration_point    = false;
						$this->change_parsing_namespace( 'html' );
						$foreign_content_starts_at = PHP_INT_MAX;
						$foreign_closed_blocks     = array();
					} elseif ( '#tag' === $token_type && ! $has_self_closing_flag ) {
						switch ( $token_name ) {
							case 'MI':
							case 'MN':
							case 'MO':
							case 'MS':
							case 'MTEXT':
								$is_in_mathml_text_integration_point = ! $is_closer && 'math' === $namespace;
								break;

							case 'DESC':
							case 'FOREIGNOBJECT':
							case 'TITLE':
								$is_in_svg_html_integration_point = ! $is_closer && 'svg' === $namespace;
								break;
						}
					}
				}

				if ( 'TEMPLATE' === $token_name && $template_depth > 0 && $is_closer && 'html' === $namespace ) {
					--$template_depth;
				}
			}

			/*
			 * While there might have been an incomplete token in the output stream,
			 * there is no need to render it to the output. They would disappear on
			 * their own in a browser if they ended the document, but here they do
			 * not end the document; instead, they are likely being inserted into an
			 * existing document, where the incomplete token might mess with the rest
			 * of the page’s HTML structure.
			 */

			$sanitized = substr( $output, 0, $foreign_content_starts_at );

			// Templates should be contained within blocks, so close them first.
			if ( $template_depth > 0 && isset( $this->allowed_html['template'] ) ) {
				$sanitized .= str_repeat( '</template>', $template_depth );
			}

			// Close any remaining-open blocks ensure isolation of block content.
			foreach ( $foreign_closed_blocks as $block_name ) {
				$sanitized .= "<!-- /wp:{$block_name} -->";
			}

			for ( $i = count( $open_blocks ) - 1; $i >= 0; $i-- ) {
				// Skip blocks that were opened when inside truncated foreign content.
				if ( $open_blocks_at[ $i ] >= $foreign_content_starts_at ) {
					continue;
				}

				$block_name = $open_blocks[ $i ];
				$sanitized .= "<!-- /wp:{$block_name} -->";
			}

			return $sanitized;
		}
	};

	return $processor->sanitize();
}