formatting.php

<?php
/**
 * Main WordPress Formatting API.
 *
 * Handles many functions for formatting output.
 *
 * @package WordPress
 */

/**
 * Replaces common plain text characters with formatted entities.
 *
 * Returns given text with transformations of quotes into smart quotes, apostrophes,
 * dashes, ellipses, the trademark symbol, and the multiplication symbol.
 *
 * As an example,
 *
 *     'cause today's effort makes it worth tomorrow's "holiday" ...
 *
 * Becomes:
 *
 *     &#8217;cause today&#8217;s effort makes it worth tomorrow&#8217;s &#8220;holiday&#8221; &#8230;
 *
 * Code within certain HTML blocks are skipped.
 *
 * Do not use this function before the {@see 'init'} action hook; everything will break.
 *
 * @since 0.71
 *
 * @global array $wp_cockneyreplace Array of formatted entities for certain common phrases.
 * @global array $shortcode_tags
 *
 * @param string $text  The text to be formatted.
 * @param bool   $reset Set to true for unit testing. Translated patterns will reset.
 * @return string The string replaced with HTML entities.
 */
function wptexturize( $text, $reset = false ) {
	global $wp_cockneyreplace, $shortcode_tags;
	static $static_characters            = null,
		$static_replacements             = null,
		$dynamic_characters              = null,
		$dynamic_replacements            = null,
		$default_no_texturize_tags       = null,
		$default_no_texturize_shortcodes = null,
		$run_texturize                   = true,
		$apos                            = null,
		$prime                           = null,
		$double_prime                    = null,
		$opening_quote                   = null,
		$closing_quote                   = null,
		$opening_single_quote            = null,
		$closing_single_quote            = null,
		$open_q_flag                     = '<!--oq-->',
		$open_sq_flag                    = '<!--osq-->',
		$apos_flag                       = '<!--apos-->';

	// If there's nothing to do, just stop.
	if ( empty( $text ) || false === $run_texturize ) {
		return $text;
	}

	// Set up static variables. Run once only.
	if ( $reset || ! isset( $static_characters ) ) {
		/**
		 * Filters whether to skip running wptexturize().
		 *
		 * Returning false from the filter will effectively short-circuit wptexturize()
		 * and return the original text passed to the function instead.
		 *
		 * The filter runs only once, the first time wptexturize() is called.
		 *
		 * @since 4.0.0
		 *
		 * @see wptexturize()
		 *
		 * @param bool $run_texturize Whether to short-circuit wptexturize().
		 */
		$run_texturize = apply_filters( 'run_wptexturize', $run_texturize );
		if ( false === $run_texturize ) {
			return $text;
		}

		/* translators: Opening curly double quote. */
		$opening_quote = _x( '&#8220;', 'opening curly double quote' );
		/* translators: Closing curly double quote. */
		$closing_quote = _x( '&#8221;', 'closing curly double quote' );

		/* translators: Apostrophe, for example in 'cause or can't. */
		$apos = _x( '&#8217;', 'apostrophe' );

		/* translators: Prime, for example in 9' (nine feet). */
		$prime = _x( '&#8242;', 'prime' );
		/* translators: Double prime, for example in 9" (nine inches). */
		$double_prime = _x( '&#8243;', 'double prime' );

		/* translators: Opening curly single quote. */
		$opening_single_quote = _x( '&#8216;', 'opening curly single quote' );
		/* translators: Closing curly single quote. */
		$closing_single_quote = _x( '&#8217;', 'closing curly single quote' );

		/* translators: En dash. */
		$en_dash = _x( '&#8211;', 'en dash' );
		/* translators: Em dash. */
		$em_dash = _x( '&#8212;', 'em dash' );

		$default_no_texturize_tags       = array( 'pre', 'code', 'kbd', 'style', 'script', 'tt' );
		$default_no_texturize_shortcodes = array( 'code' );

		// If a plugin has provided an autocorrect array, use it.
		if ( isset( $wp_cockneyreplace ) ) {
			$cockney        = array_keys( $wp_cockneyreplace );
			$cockneyreplace = array_values( $wp_cockneyreplace );
		} else {
			/*
			 * translators: This is a comma-separated list of words that defy the syntax of quotations in normal use,
			 * for example... 'We do not have enough words yet'... is a typical quoted phrase. But when we write
			 * lines of code 'til we have enough of 'em, then we need to insert apostrophes instead of quotes.
			 */
			$cockney = explode(
				',',
				_x(
					"'tain't,'twere,'twas,'tis,'twill,'til,'bout,'nuff,'round,'cause,'em",
					'Comma-separated list of words to texturize in your language'
				)
			);

			$cockneyreplace = explode(
				',',
				_x(
					'&#8217;tain&#8217;t,&#8217;twere,&#8217;twas,&#8217;tis,&#8217;twill,&#8217;til,&#8217;bout,&#8217;nuff,&#8217;round,&#8217;cause,&#8217;em',
					'Comma-separated list of replacement words in your language'
				)
			);
		}

		$static_characters   = array_merge( array( '...', '``', '\'\'', ' (tm)' ), $cockney );
		$static_replacements = array_merge( array( '&#8230;', $opening_quote, $closing_quote, ' &#8482;' ), $cockneyreplace );

		/*
		 * Pattern-based replacements of characters.
		 * Sort the remaining patterns into several arrays for performance tuning.
		 */
		$dynamic_characters   = array(
			'apos'  => array(),
			'quote' => array(),
			'dash'  => array(),
		);
		$dynamic_replacements = array(
			'apos'  => array(),
			'quote' => array(),
			'dash'  => array(),
		);
		$dynamic              = array();
		$spaces               = wp_spaces_regexp();

		// '99' and '99" are ambiguous among other patterns; assume it's an abbreviated year at the end of a quotation.
		if ( "'" !== $apos || "'" !== $closing_single_quote ) {
			$dynamic[ '/\'(\d\d)\'(?=\Z|[.,:;!?)}\-\]]|&gt;|' . $spaces . ')/' ] = $apos_flag . '$1' . $closing_single_quote;
		}
		if ( "'" !== $apos || '"' !== $closing_quote ) {
			$dynamic[ '/\'(\d\d)"(?=\Z|[.,:;!?)}\-\]]|&gt;|' . $spaces . ')/' ] = $apos_flag . '$1' . $closing_quote;
		}

		// '99 '99s '99's (apostrophe)  But never '9 or '99% or '999 or '99.0.
		if ( "'" !== $apos ) {
			$dynamic['/\'(?=\d\d(?:\Z|(?![%\d]|[.,]\d)))/'] = $apos_flag;
		}

		// Quoted numbers like '0.42'.
		if ( "'" !== $opening_single_quote && "'" !== $closing_single_quote ) {
			$dynamic[ '/(?<=\A|' . $spaces . ')\'(\d[.,\d]*)\'/' ] = $open_sq_flag . '$1' . $closing_single_quote;
		}

		// Single quote at start, or preceded by (, {, <, [, ", -, or spaces.
		if ( "'" !== $opening_single_quote ) {
			$dynamic[ '/(?<=\A|[([{"\-]|&lt;|' . $spaces . ')\'/' ] = $open_sq_flag;
		}

		// Apostrophe in a word. No spaces, double apostrophes, or other punctuation.
		if ( "'" !== $apos ) {
			$dynamic[ '/(?<!' . $spaces . ')\'(?!\Z|[.,:;!?"\'(){}[\]\-]|&[lg]t;|' . $spaces . ')/' ] = $apos_flag;
		}

		$dynamic_characters['apos']   = array_keys( $dynamic );
		$dynamic_replacements['apos'] = array_values( $dynamic );
		$dynamic                      = array();

		// Quoted numbers like "42".
		if ( '"' !== $opening_quote && '"' !== $closing_quote ) {
			$dynamic[ '/(?<=\A|' . $spaces . ')"(\d[.,\d]*)"/' ] = $open_q_flag . '$1' . $closing_quote;
		}

		// Double quote at start, or preceded by (, {, <, [, -, or spaces, and not followed by spaces.
		if ( '"' !== $opening_quote ) {
			$dynamic[ '/(?<=\A|[([{\-]|&lt;|' . $spaces . ')"(?!' . $spaces . ')/' ] = $open_q_flag;
		}

		$dynamic_characters['quote']   = array_keys( $dynamic );
		$dynamic_replacements['quote'] = array_values( $dynamic );
		$dynamic                       = array();

		// Dashes and spaces.
		$dynamic['/---/'] = $em_dash;
		$dynamic[ '/(?<=^|' . $spaces . ')--(?=$|' . $spaces . ')/' ] = $em_dash;
		$dynamic['/(?<!xn)--/']                                       = $en_dash;
		$dynamic[ '/(?<=^|' . $spaces . ')-(?=$|' . $spaces . ')/' ]  = $en_dash;

		$dynamic_characters['dash']   = array_keys( $dynamic );
		$dynamic_replacements['dash'] = array_values( $dynamic );
	}

	// Must do this every time in case plugins use these filters in a context sensitive manner.
	/**
	 * Filters the list of HTML elements not to texturize.
	 *
	 * @since 2.8.0
	 *
	 * @param string[] $default_no_texturize_tags An array of HTML element names.
	 */
	$no_texturize_tags = apply_filters( 'no_texturize_tags', $default_no_texturize_tags );
	/**
	 * Filters the list of shortcodes not to texturize.
	 *
	 * @since 2.8.0
	 *
	 * @param string[] $default_no_texturize_shortcodes An array of shortcode names.
	 */
	$no_texturize_shortcodes = apply_filters( 'no_texturize_shortcodes', $default_no_texturize_shortcodes );

	$no_texturize_tags_stack       = array();
	$no_texturize_shortcodes_stack = array();

	// Look for shortcodes and HTML elements.

	preg_match_all( '@\[/?([^<>&/\[\]\x00-\x20=]++)@', $text, $matches );
	$tagnames         = array_intersect( array_keys( $shortcode_tags ), $matches[1] );
	$found_shortcodes = ! empty( $tagnames );
	$shortcode_regex  = $found_shortcodes ? _get_wptexturize_shortcode_regex( $tagnames ) : '';
	$regex            = _get_wptexturize_split_regex( $shortcode_regex );

	$textarr = preg_split( $regex, $text, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );

	foreach ( $textarr as &$curl ) {
		// Only call _wptexturize_pushpop_element if $curl is a delimiter.
		$first = $curl[0];
		if ( '<' === $first ) {
			if ( str_starts_with( $curl, '<!--' ) ) {
				// This is an HTML comment delimiter.
				continue;
			} else {
				// This is an HTML element delimiter.

				// Replace each & with &#038; unless it already looks like an entity.
				$curl = preg_replace( '/&(?!#(?:\d+|x[a-f0-9]+);|[a-z1-4]{1,8};)/i', '&#038;', $curl );

				_wptexturize_pushpop_element( $curl, $no_texturize_tags_stack, $no_texturize_tags );
			}
		} elseif ( '' === trim( $curl ) ) {
			// This is a newline between delimiters. Performance improves when we check this.
			continue;

		} elseif ( '[' === $first && $found_shortcodes && 1 === preg_match( '/^' . $shortcode_regex . '$/', $curl ) ) {
			// This is a shortcode delimiter.

			if ( ! str_starts_with( $curl, '[[' ) && ! str_ends_with( $curl, ']]' ) ) {
				// Looks like a normal shortcode.
				_wptexturize_pushpop_element( $curl, $no_texturize_shortcodes_stack, $no_texturize_shortcodes );
			} else {
				// Looks like an escaped shortcode.
				continue;
			}
		} elseif ( empty( $no_texturize_shortcodes_stack ) && empty( $no_texturize_tags_stack ) ) {
			// This is neither a delimiter, nor is this content inside of no_texturize pairs. Do texturize.

			$curl = str_replace( $static_characters, $static_replacements, $curl );

			if ( str_contains( $curl, "'" ) ) {
				$curl = preg_replace( $dynamic_characters['apos'], $dynamic_replacements['apos'], $curl );
				$curl = wptexturize_primes( $curl, "'", $prime, $open_sq_flag, $closing_single_quote );
				$curl = str_replace( $apos_flag, $apos, $curl );
				$curl = str_replace( $open_sq_flag, $opening_single_quote, $curl );
			}
			if ( str_contains( $curl, '"' ) ) {
				$curl = preg_replace( $dynamic_characters['quote'], $dynamic_replacements['quote'], $curl );
				$curl = wptexturize_primes( $curl, '"', $double_prime, $open_q_flag, $closing_quote );
				$curl = str_replace( $open_q_flag, $opening_quote, $curl );
			}
			if ( str_contains( $curl, '-' ) ) {
				$curl = preg_replace( $dynamic_characters['dash'], $dynamic_replacements['dash'], $curl );
			}

			// 9x9 (times), but never 0x9999.
			if ( 1 === preg_match( '/(?<=\d)x\d/', $curl ) ) {
				// Searching for a digit is 10 times more expensive than for the x, so we avoid doing this one!
				$curl = preg_replace( '/\b(\d(?(?<=0)[\d\.,]+|[\d\.,]*))x(\d[\d\.,]*)\b/', '$1&#215;$2', $curl );
			}

			// Replace each & with &#038; unless it already looks like an entity.
			$curl = preg_replace( '/&(?!#(?:\d+|x[a-f0-9]+);|[a-z1-4]{1,8};)/i', '&#038;', $curl );
		}
	}

	return implode( '', $textarr );
}

/**
 * Implements a logic tree to determine whether or not "7'." represents seven feet,
 * then converts the special char into either a prime char or a closing quote char.
 *
 * @since 4.3.0
 *
 * @param string $haystack    The plain text to be searched.
 * @param string $needle      The character to search for such as ' or ".
 * @param string $prime       The prime char to use for replacement.
 * @param string $open_quote  The opening quote char. Opening quote replacement must be
 *                            accomplished already.
 * @param string $close_quote The closing quote char to use for replacement.
 * @return string The $haystack value after primes and quotes replacements.
 */
function wptexturize_primes( $haystack, $needle, $prime, $open_quote, $close_quote ) {
	$spaces           = wp_spaces_regexp();
	$flag             = '<!--wp-prime-or-quote-->';
	$quote_pattern    = "/$needle(?=\\Z|[.,:;!?)}\\-\\]]|&gt;|" . $spaces . ')/';
	$prime_pattern    = "/(?<=\\d)$needle/";
	$flag_after_digit = "/(?<=\\d)$flag/";
	$flag_no_digit    = "/(?<!\\d)$flag/";

	$sentences = explode( $open_quote, $haystack );

	foreach ( $sentences as $key => &$sentence ) {
		if ( ! str_contains( $sentence, $needle ) ) {
			continue;
		} elseif ( 0 !== $key && 0 === substr_count( $sentence, $close_quote ) ) {
			$sentence = preg_replace( $quote_pattern, $flag, $sentence, -1, $count );
			if ( $count > 1 ) {
				// This sentence appears to have multiple closing quotes. Attempt Vulcan logic.
				$sentence = preg_replace( $flag_no_digit, $close_quote, $sentence, -1, $count2 );
				if ( 0 === $count2 ) {
					// Try looking for a quote followed by a period.
					$count2 = substr_count( $sentence, "$flag." );
					if ( $count2 > 0 ) {
						// Assume the rightmost quote-period match is the end of quotation.
						$pos = strrpos( $sentence, "$flag." );
					} else {
						/*
						 * When all else fails, make the rightmost candidate a closing quote.
						 * This is most likely to be problematic in the context of bug #18549.
						 */
						$pos = strrpos( $sentence, $flag );
					}
					$sentence = substr_replace( $sentence, $close_quote, $pos, strlen( $flag ) );
				}
				// Use conventional replacement on any remaining primes and quotes.
				$sentence = preg_replace( $prime_pattern, $prime, $sentence );
				$sentence = preg_replace( $flag_after_digit, $prime, $sentence );
				$sentence = str_replace( $flag, $close_quote, $sentence );
			} elseif ( 1 === $count ) {
				// Found only one closing quote candidate, so give it priority over primes.
				$sentence = str_replace( $flag, $close_quote, $sentence );
				$sentence = preg_replace( $prime_pattern, $prime, $sentence );
			} else {
				// No closing quotes found. Just run primes pattern.
				$sentence = preg_replace( $prime_pattern, $prime, $sentence );
			}
		} else {
			$sentence = preg_replace( $prime_pattern, $prime, $sentence );
			$sentence = preg_replace( $quote_pattern, $close_quote, $sentence );
		}
		if ( '"' === $needle && str_contains( $sentence, '"' ) ) {
			$sentence = str_replace( '"', $close_quote, $sentence );
		}
	}

	return implode( $open_quote, $sentences );
}

/**
 * Searches for disabled element tags. Pushes element to stack on tag open
 * and pops on tag close.
 *
 * Assumes first char of `$text` is tag opening and last char is tag closing.
 * Assumes second char of `$text` is optionally `/` to indicate closing as in `</html>`.
 *
 * @since 2.9.0
 * @access private
 *
 * @param string   $text              Text to check. Must be a tag like `<html>` or `[shortcode]`.
 * @param string[] $stack             Array of open tag elements.
 * @param string[] $disabled_elements Array of tag names to match against. Spaces are not allowed in tag names.
 */
function _wptexturize_pushpop_element( $text, &$stack, $disabled_elements ) {
	// Is it an opening tag or closing tag?
	if ( isset( $text[1] ) && '/' !== $text[1] ) {
		$opening_tag = true;
		$name_offset = 1;
	} elseif ( 0 === count( $stack ) ) {
		// Stack is empty. Just stop.
		return;
	} else {
		$opening_tag = false;
		$name_offset = 2;
	}

	// Parse out the tag name.
	$space = strpos( $text, ' ' );
	if ( false === $space ) {
		$space = -1;
	} else {
		$space -= $name_offset;
	}
	$tag = substr( $text, $name_offset, $space );

	// Handle disabled tags.
	if ( in_array( $tag, $disabled_elements, true ) ) {
		if ( $opening_tag ) {
			/*
			 * This disables texturize until we find a closing tag of our type
			 * (e.g. <pre>) even if there was invalid nesting before that.
			 *
			 * Example: in the case <pre>sadsadasd</code>"baba"</pre>
			 *          "baba" won't be texturized.
			 */

			array_push( $stack, $tag );
		} elseif ( end( $stack ) === $tag ) {
			array_pop( $stack );
		}
	}
}

/**
 * Replaces double line breaks with paragraph elements.
 *
 * A group of regex replaces used to identify text formatted with newlines and
 * replace double line breaks with HTML paragraph tags. The remaining line breaks
 * after conversion become `<br />` tags, unless `$br` is set to '0' or 'false'.
 *
 * @since 0.71
 *
 * @param string $text The text which has to be formatted.
 * @param bool   $br   Optional. If set, this will convert all remaining line breaks
 *                     after paragraphing. Line breaks within `<script>`, `<style>`,
 *                     and `<svg>` tags are not affected. Default true.
 * @return string Text which has been converted into correct paragraph tags.
 */
function wpautop( $text, $br = true ) {
	$pre_tags = array();

	if ( '' === trim( $text ) ) {
		return '';
	}

	// Just to make things a little easier, pad the end.
	$text = $text . "\n";

	/*
	 * Pre tags shouldn't be touched by autop.
	 * Replace pre tags with placeholders and bring them back after autop.
	 */
	if ( str_contains( $text, '<pre' ) ) {
		$text_parts = explode( '</pre>', $text );
		$last_part  = array_pop( $text_parts );
		$text       = '';
		$i          = 0;

		foreach ( $text_parts as $text_part ) {
			$start = strpos( $text_part, '<pre' );

			// Malformed HTML?
			if ( false === $start ) {
				$text .= $text_part;
				continue;
			}

			$name              = "<pre wp-pre-tag-$i></pre>";
			$pre_tags[ $name ] = substr( $text_part, $start ) . '</pre>';

			$text .= substr( $text_part, 0, $start ) . $name;
			++$i;
		}

		$text .= $last_part;
	}
	// Change multiple <br>'s into two line breaks, which will turn into paragraphs.
	$text = preg_replace( '|<br\s*/?>\s*<br\s*/?>|', "\n\n", $text );

	$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|form|map|area|blockquote|address|style|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';

	// Add a double line break above block-level opening tags.
	$text = preg_replace( '!(<' . $allblocks . '[\s/>])!', "\n\n$1", $text );

	// Add a double line break below block-level closing tags.
	$text = preg_replace( '!(</' . $allblocks . '>)!', "$1\n\n", $text );

	// Add a double line break after hr tags, which are self closing.
	$text = preg_replace( '!(<hr\s*?/?>)!', "$1\n\n", $text );

	// Standardize newline characters to "\n".
	$text = str_replace( array( "\r\n", "\r" ), "\n", $text );

	// Find newlines in all elements and add placeholders.
	$text = wp_replace_in_html_tags( $text, array( "\n" => ' <!-- wpnl --> ' ) );

	// Collapse line breaks before and after <option> elements so they don't get autop'd.
	if ( str_contains( $text, '<option' ) ) {
		$text = preg_replace( '|\s*<option|', '<option', $text );
		$text = preg_replace( '|</option>\s*|', '</option>', $text );
	}

	/*
	 * Collapse line breaks inside <object> elements, before <param> and <embed> elements
	 * so they don't get autop'd.
	 */
	if ( str_contains( $text, '</object>' ) ) {
		$text = preg_replace( '|(<object[^>]*>)\s*|', '$1', $text );
		$text = preg_replace( '|\s*</object>|', '</object>', $text );
		$text = preg_replace( '%\s*(</?(?:param|embed)[^>]*>)\s*%', '$1', $text );
	}

	/*
	 * Collapse line breaks inside <audio> and <video> elements,
	 * before and after <source> and <track> elements.
	 */
	if ( str_contains( $text, '<source' ) || str_contains( $text, '<track' ) ) {
		$text = preg_replace( '%([<\[](?:audio|video)[^>\]]*[>\]])\s*%', '$1', $text );
		$text = preg_replace( '%\s*([<\[]/(?:audio|video)[>\]])%', '$1', $text );
		$text = preg_replace( '%\s*(<(?:source|track)[^>]*>)\s*%', '$1', $text );
	}

	// Collapse line breaks before and after <figcaption> elements.
	if ( str_contains( $text, '<figcaption' ) ) {
		$text = preg_replace( '|\s*(<figcaption[^>]*>)|', '$1', $text );
		$text = preg_replace( '|</figcaption>\s*|', '</figcaption>', $text );
	}

	// Remove more than two contiguous line breaks.
	$text = preg_replace( "/\n\n+/", "\n\n", $text );

	// Split up the contents into an array of strings, separated by double line breaks.
	$paragraphs = preg_split( '/\n\s*\n/', $text, -1, PREG_SPLIT_NO_EMPTY );

	// Reset $text prior to rebuilding.
	$text = '';

	// Rebuild the content as a string, wrapping every bit with a <p>.
	foreach ( $paragraphs as $paragraph ) {
		$text .= '<p>' . trim( $paragraph, "\n" ) . "</p>\n";
	}

	// Under certain strange conditions it could create a P of entirely whitespace.
	$text = preg_replace( '|<p>\s*</p>|', '', $text );

	// Add a closing <p> inside <div>, <address>, or <form> tag if missing.
	$text = preg_replace( '!<p>([^<]+)</(div|address|form)>!', '<p>$1</p></$2>', $text );

	// If an opening or closing block element tag is wrapped in a <p>, unwrap it.
	$text = preg_replace( '!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', '$1', $text );

	// In some cases <li> may get wrapped in <p>, fix them.
	$text = preg_replace( '|<p>(<li.+?)</p>|', '$1', $text );

	// If a <blockquote> is wrapped with a <p>, move it inside the <blockquote>.
	$text = preg_replace( '|<p><blockquote([^>]*)>|i', '<blockquote$1><p>', $text );
	$text = str_replace( '</blockquote></p>', '</p></blockquote>', $text );

	// If an opening or closing block element tag is preceded by an opening <p> tag, remove it.
	$text = preg_replace( '!<p>\s*(</?' . $allblocks . '[^>]*>)!', '$1', $text );

	// If an opening or closing block element tag is followed by a closing <p> tag, remove it.
	$text = preg_replace( '!(</?' . $allblocks . '[^>]*>)\s*</p>!', '$1', $text );

	// Optionally insert line breaks.
	if ( $br ) {
		// Replace newlines that shouldn't be touched with a placeholder.
		$text = preg_replace_callback( '/<(script|style|svg|math).*?<\/\\1>/s', '_autop_newline_preservation_helper', $text );

		// Normalize <br>.
		$text = str_replace( array( '<br>', '<br/>' ), '<br />', $text );

		// Replace any new line characters that aren't preceded by a <br /> with a <br />.
		$text = preg_replace( '|(?<!<br />)\s*\n|', "<br />\n", $text );

		// Replace newline placeholders with newlines.
		$text = str_replace( '<WPPreserveNewline />', "\n", $text );
	}

	// If a <br /> tag is after an opening or closing block tag, remove it.
	$text = preg_replace( '!(</?' . $allblocks . '[^>]*>)\s*<br />!', '$1', $text );

	// If a <br /> tag is before a subset of opening or closing block tags, remove it.
	$text = preg_replace( '!<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)!', '$1', $text );
	$text = preg_replace( "|\n</p>$|", '</p>', $text );

	// Replace placeholder <pre> tags with their original content.
	if ( ! empty( $pre_tags ) ) {
		$text = str_replace( array_keys( $pre_tags ), array_values( $pre_tags ), $text );
	}

	// Restore newlines in all elements.
	if ( str_contains( $text, '<!-- wpnl -->' ) ) {
		$text = str_replace( array( ' <!-- wpnl --> ', '<!-- wpnl -->' ), "\n", $text );
	}

	return $text;
}

/**
 * Separates HTML elements and comments from the text.
 *
 * @since 4.2.4
 *
 * @param string $input The text which has to be formatted.
 * @return string[] Array of the formatted text.
 */
function wp_html_split( $input ) {
	return preg_split( get_html_split_regex(), $input, -1, PREG_SPLIT_DELIM_CAPTURE );
}

/**
 * Retrieves the regular expression for an HTML element.
 *
 * @since 4.4.0
 *
 * @return string The regular expression.
 */
function get_html_split_regex() {
	static $regex;

	if ( ! isset( $regex ) ) {
		// phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound -- don't remove regex indentation
		$comments =
			'!'             // Start of comment, after the <.
			. '(?:'         // Unroll the loop: Consume everything until --> is found.
			.     '-(?!->)' // Dash not followed by end of comment.
			.     '[^\-]*+' // Consume non-dashes.
			. ')*+'         // Loop possessively.
			. '(?:-->)?';   // End of comment. If not found, match all input.

		$cdata =
			'!\[CDATA\['    // Start of comment, after the <.
			. '[^\]]*+'     // Consume non-].
			. '(?:'         // Unroll the loop: Consume everything until ]]> is found.
			.     '](?!]>)' // One ] not followed by end of comment.
			.     '[^\]]*+' // Consume non-].
			. ')*+'         // Loop possessively.
			. '(?:]]>)?';   // End of comment. If not found, match all input.

		$escaped =
			'(?='             // Is the element escaped?
			.    '!--'
			. '|'
			.    '!\[CDATA\['
			. ')'
			. '(?(?=!-)'      // If yes, which type?
			.     $comments
			. '|'
			.     $cdata
			. ')';

		$regex =
			'/('                // Capture the entire match.
			.     '<'           // Find start of element.
			.     '(?'          // Conditional expression follows.
			.         $escaped  // Find end of escaped element.
			.     '|'           // ...else...
			.         '[^>]*>?' // Find end of normal element.
			.     ')'
			. ')/';
		// phpcs:enable
	}

	return $regex;
}

/**
 * Retrieves the combined regular expression for HTML and shortcodes.
 *
 * @access private
 * @ignore
 * @internal This function will be removed in 4.5.0 per Shortcode API Roadmap.
 * @since 4.4.0
 *
 * @param string $shortcode_regex Optional. The result from _get_wptexturize_shortcode_regex().
 * @return string The regular expression.
 */
function _get_wptexturize_split_regex( $shortcode_regex = '' ) {
	static $html_regex;

	if ( ! isset( $html_regex ) ) {
		// phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound -- don't remove regex indentation
		$comment_regex =
			'!'             // Start of comment, after the <.
			. '(?:'         // Unroll the loop: Consume everything until --> is found.
			.     '-(?!->)' // Dash not followed by end of comment.
			.     '[^\-]*+' // Consume non-dashes.
			. ')*+'         // Loop possessively.
			. '(?:-->)?';   // End of comment. If not found, match all input.

		$html_regex = // Needs replaced with wp_html_split() per Shortcode API Roadmap.
			'<'                  // Find start of element.
			. '(?(?=!--)'        // Is this a comment?
			.     $comment_regex // Find end of comment.
			. '|'
			.     '[^>]*>?'      // Find end of element. If not found, match all input.
			. ')';
		// phpcs:enable
	}

	if ( empty( $shortcode_regex ) ) {
		$regex = '/(' . $html_regex . ')/';
	} else {
		$regex = '/(' . $html_regex . '|' . $shortcode_regex . ')/';
	}

	return $regex;
}

/**
 * Retrieves the regular expression for shortcodes.
 *
 * @access private
 * @ignore
 * @since 4.4.0
 *
 * @param string[] $tagnames Array of shortcodes to find.
 * @return string The regular expression.
 */
function _get_wptexturize_shortcode_regex( $tagnames ) {
	$tagregexp = implode( '|', array_map( 'preg_quote', $tagnames ) );
	$tagregexp = "(?:$tagregexp)(?=[\\s\\]\\/])"; // Excerpt of get_shortcode_regex().
	// phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound -- don't remove regex indentation
	$regex =
		'\['                // Find start of shortcode.
		. '[\/\[]?'         // Shortcodes may begin with [/ or [[.
		. $tagregexp        // Only match registered shortcodes, because performance.
		. '(?:'
		.     '[^\[\]<>]+'  // Shortcodes do not contain other shortcodes. Quantifier critical.
		. '|'
		.     '<[^\[\]>]*>' // HTML elements permitted. Prevents matching ] before >.
		. ')*+'             // Possessive critical.
		. '\]'              // Find end of shortcode.
		. '\]?';            // Shortcodes may end with ]].
	// phpcs:enable

	return $regex;
}

/**
 * Replaces characters or phrases within HTML elements only.
 *
 * @since 4.2.3
 *
 * @param string $haystack      The text which has to be formatted.
 * @param array  $replace_pairs In the form array('from' => 'to', ...).
 * @return string The formatted text.
 */
function wp_replace_in_html_tags( $haystack, $replace_pairs ) {
	// Find all elements.
	$textarr = wp_html_split( $haystack );
	$changed = false;

	// Optimize when searching for one item.
	if ( 1 === count( $replace_pairs ) ) {
		// Extract $needle and $replace.
		$needle  = array_key_first( $replace_pairs );
		$replace = $replace_pairs[ $needle ];

		// Loop through delimiters (elements) only.
		for ( $i = 1, $c = count( $textarr ); $i < $c; $i += 2 ) {
			if ( str_contains( $textarr[ $i ], $needle ) ) {
				$textarr[ $i ] = str_replace( $needle, $replace, $textarr[ $i ] );
				$changed       = true;
			}
		}
	} else {
		// Extract all $needles.
		$needles = array_keys( $replace_pairs );

		// Loop through delimiters (elements) only.
		for ( $i = 1, $c = count( $textarr ); $i < $c; $i += 2 ) {
			foreach ( $needles as $needle ) {
				if ( str_contains( $textarr[ $i ], $needle ) ) {
					$textarr[ $i ] = strtr( $textarr[ $i ], $replace_pairs );
					$changed       = true;
					// After one strtr() break out of the foreach loop and look at next element.
					break;
				}
			}
		}
	}

	if ( $changed ) {
		$haystack = implode( $textarr );
	}

	return $haystack;
}

/**
 * Newline preservation help function for wpautop().
 *
 * @since 3.1.0
 * @access private
 *
 * @param array $matches preg_replace_callback matches array
 * @return string
 */
function _autop_newline_preservation_helper( $matches ) {
	return str_replace( "\n", '<WPPreserveNewline />', $matches[0] );
}

/**
 * Don't auto-p wrap shortcodes that stand alone.
 *
 * Ensures that shortcodes are not wrapped in `<p>...</p>`.
 *
 * @since 2.9.0
 *
 * @global array $shortcode_tags
 *
 * @param string $text The content.
 * @return string The filtered content.
 */
function shortcode_unautop( $text ) {
	global $shortcode_tags;

	if ( empty( $shortcode_tags ) || ! is_array( $shortcode_tags ) ) {
		return $text;
	}

	$tagregexp = implode( '|', array_map( 'preg_quote', array_keys( $shortcode_tags ) ) );
	$spaces    = wp_spaces_regexp();

	// phpcs:disable Squiz.Strings.ConcatenationSpacing.PaddingFound,Universal.WhiteSpace.PrecisionAlignment.Found -- don't remove regex indentation
	$pattern =
		'/'
		. '<p>'                              // Opening paragraph.
		. '(?:' . $spaces . ')*+'            // Optional leading whitespace.
		. '('                                // 1: The shortcode.
		.     '\\['                          // Opening bracket.
		.     "($tagregexp)"                 // 2: Shortcode name.
		.     '(?![\\w-])'                   // Not followed by word character or hyphen.
											 // Unroll the loop: Inside the opening shortcode tag.
		.     '[^\\]\\/]*'                   // Not a closing bracket or forward slash.
		.     '(?:'
		.         '\\/(?!\\])'               // A forward slash not followed by a closing bracket.
		.         '[^\\]\\/]*'               // Not a closing bracket or forward slash.
		.     ')*?'
		.     '(?:'
		.         '\\/\\]'                   // Self closing tag and closing bracket.
		.     '|'
		.         '\\]'                      // Closing bracket.
		.         '(?:'                      // Unroll the loop: Optionally, anything between the opening and closing shortcode tags.
		.             '[^\\[]*+'             // Not an opening bracket.
		.             '(?:'
		.                 '\\[(?!\\/\\2\\])' // An opening bracket not followed by the closing shortcode tag.
		.                 '[^\\[]*+'         // Not an opening bracket.
		.             ')*+'
		.             '\\[\\/\\2\\]'         // Closing shortcode tag.
		.         ')?'
		.     ')'
		. ')'
		. '(?:' . $spaces . ')*+'            // Optional trailing whitespace.
		. '<\\/p>'                           // Closing paragraph.
		. '/';
	// phpcs:enable

	return preg_replace( $pattern, '$1', $text );
}

/**
 * Checks to see if a string is utf8 encoded.
 *
 * NOTE: This function checks for 5-Byte sequences, UTF8
 *       has Bytes Sequences with a maximum length of 4.
 *
 * @author bmorel at ssi dot fr (modified)
 * @since 1.2.1
 * @deprecated 6.9.0 Use {@see wp_is_valid_utf8()} instead.
 *
 * @param string $str The string to be checked.
 * @return bool True if $str fits a UTF-8 model, false otherwise.
 */
function seems_utf8( $str ) {
	_deprecated_function( __FUNCTION__, '6.9.0', 'wp_is_valid_utf8()' );

	mbstring_binary_safe_encoding();
	$length = strlen( $str );
	reset_mbstring_encoding();

	for ( $i = 0; $i < $length; $i++ ) {
		$c = ord( $str[ $i ] );

		if ( $c < 0x80 ) {
			$n = 0; // 0bbbbbbb
		} elseif ( ( $c & 0xE0 ) === 0xC0 ) {
			$n = 1; // 110bbbbb
		} elseif ( ( $c & 0xF0 ) === 0xE0 ) {
			$n = 2; // 1110bbbb
		} elseif ( ( $c & 0xF8 ) === 0xF0 ) {
			$n = 3; // 11110bbb
		} elseif ( ( $c & 0xFC ) === 0xF8 ) {
			$n = 4; // 111110bb
		} elseif ( ( $c & 0xFE ) === 0xFC ) {
			$n = 5; // 1111110b
		} else {
			return false; // Does not match any model.
		}

		for ( $j = 0; $j < $n; $j++ ) { // n bytes matching 10bbbbbb follow?
			if ( ( ++$i === $length ) || ( ( ord( $str[ $i ] ) & 0xC0 ) !== 0x80 ) ) {
				return false;
			}
		}
	}

	return true;
}

/**
 * Converts a number of special characters into their HTML entities.
 *
 * Specifically deals with: `&`, `<`, `>`, `"`, and `'`.
 *
 * `$quote_style` can be set to ENT_COMPAT to encode `"` to
 * `&quot;`, or ENT_QUOTES to do both. Default is ENT_NOQUOTES where no quotes are encoded.
 *
 * @since 1.2.2
 * @since 5.5.0 `$quote_style` also accepts `ENT_XML1`.
 * @access private
 *
 * @param string       $text          The text which is to be encoded.
 * @param int|string   $quote_style   Optional. Converts double quotes if set to ENT_COMPAT,
 *                                    both single and double if set to ENT_QUOTES or none if set to ENT_NOQUOTES.
 *                                    Converts single and double quotes, as well as converting HTML
 *                                    named entities (that are not also XML named entities) to their
 *                                    code points if set to ENT_XML1. Also compatible with old values;
 *                                    converting single quotes if set to 'single',
 *                                    double if set to 'double' or both if otherwise set.
 *                                    Default is ENT_NOQUOTES.
 * @param false|string $charset       Optional. The character encoding of the string. Default false.
 * @param bool         $double_encode Optional. Whether to encode existing HTML entities. Default false.
 * @return string The encoded text with HTML entities.
 */
function _wp_specialchars( $text, $quote_style = ENT_NOQUOTES, $charset = false, $double_encode = false ) {
	$text = (string) $text;

	if ( 0 === strlen( $text ) ) {
		return '';
	}

	// Don't bother if there are no specialchars - saves some processing.
	if ( ! preg_match( '/[&<>"\']/', $text ) ) {
		return $text;
	}

	// Account for the previous behavior of the function when the $quote_style is not an accepted value.
	if ( empty( $quote_style ) ) {
		$quote_style = ENT_NOQUOTES;
	} elseif ( ENT_XML1 === $quote_style ) {
		$quote_style = ENT_QUOTES | ENT_XML1;
	} elseif ( ! in_array( $quote_style, array( ENT_NOQUOTES, ENT_COMPAT, ENT_QUOTES, 'single', 'double' ), true ) ) {
		$quote_style = ENT_QUOTES;
	}

	$charset = _canonical_charset( $charset ? $charset : get_option( 'blog_charset' ) );

	$_quote_style = $quote_style;

	if ( 'double' === $quote_style ) {
		$quote_style  = ENT_COMPAT;
		$_quote_style = ENT_COMPAT;
	} elseif ( 'single' === $quote_style ) {
		$quote_style = ENT_NOQUOTES;
	}

	if ( ! $double_encode ) {
		/*
		 * Guarantee every &entity; is valid, convert &garbage; into &amp;garbage;
		 * This is required for PHP < 5.4.0 because ENT_HTML401 flag is unavailable.
		 */
		$text = wp_kses_normalize_entities( $text, ( $quote_style & ENT_XML1 ) ? 'xml' : 'html' );
	}

	$text = htmlspecialchars( $text, $quote_style, $charset, $double_encode );

	// Back-compat.
	if ( 'single' === $_quote_style ) {
		$text = str_replace( "'", '&#039;', $text );
	}

	return $text;
}

/**
 * Converts a number of HTML entities into their special characters.
 *
 * Specifically deals with: `&`, `<`, `>`, `"`, and `'`.
 *
 * `$quote_style` can be set to ENT_COMPAT to decode `"` entities,