WP_HTML_Processor::step_in_foreign_content(): bool

4789	private function step_in_foreign_content(): bool {4790		$tag_name   = $this->get_token_name();4791		$token_type = $this->get_token_type();4792		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';4793		$op         = "{$op_sigil}{$tag_name}";4794 4795		/*4796		 * > A start tag whose name is "font", if the token has any attributes named "color", "face", or "size"4797		 *4798		 * This section drawn out above the switch to more easily incorporate4799		 * the additional rules based on the presence of the attributes.4800		 */4801		if (4802			'+FONT' === $op &&4803			(4804				null !== $this->get_attribute( 'color' ) ||4805				null !== $this->get_attribute( 'face' ) ||4806				null !== $this->get_attribute( 'size' )4807			)4808		) {4809			$op = '+FONT with attributes';4810		}4811 4812		switch ( $op ) {4813			case '#text':4814				/*4815				 * > A character token that is U+0000 NULL4816				 *4817				 * This is handled by `get_modifiable_text()`.4818				 */4819 4820				/*4821				 * Whitespace-only text does not affect the frameset-ok flag.4822				 * It is probably inter-element whitespace, but it may also4823				 * contain character references which decode only to whitespace.4824				 */4825				if ( parent::TEXT_IS_GENERIC === $this->text_node_classification ) {4826					$this->state->frameset_ok = false;4827				}4828 4829				$this->insert_foreign_element( $this->state->current_token, false );4830				return true;4831 4832			/*4833			 * CDATA sections are alternate wrappers for text content and therefore4834			 * ought to follow the same rules as text nodes.4835			 */4836			case '#cdata-section':4837				/*4838				 * NULL bytes and whitespace do not change the frameset-ok flag.4839				 */4840				$current_token        = $this->bookmarks[ $this->state->current_token->bookmark_name ];4841				$cdata_content_start  = $current_token->start + 9;4842				$cdata_content_length = $current_token->length - 12;4843				if ( strspn( $this->html, "\0 \t\n\f\r", $cdata_content_start, $cdata_content_length ) !== $cdata_content_length ) {4844					$this->state->frameset_ok = false;4845				}4846 4847				$this->insert_foreign_element( $this->state->current_token, false );4848				return true;4849 4850			/*4851			 * > A comment token4852			 */4853			case '#comment':4854			case '#funky-comment':4855			case '#presumptuous-tag':4856				$this->insert_foreign_element( $this->state->current_token, false );4857				return true;4858 4859			/*4860			 * > A DOCTYPE token4861			 */4862			case 'html':4863				// Parse error: ignore the token.4864				return $this->step();4865 4866			/*4867			 * > A start tag whose tag name is "b", "big", "blockquote", "body", "br", "center",4868			 * > "code", "dd", "div", "dl", "dt", "em", "embed", "h1", "h2", "h3", "h4", "h5",