, or

tag if missing. $pee = preg_replace( '!

([^<]+)!', '

', $pee ); // If an opening or closing block element tag is wrapped in a

, unwrap it. $pee = preg_replace( '!

\s*(]*>)\s*

!', '$1', $pee ); // In some cases

may get wrapped in

, fix them. $pee = preg_replace( '|

(|', '$1', $pee ); // If a

is wrapped with a
, move it inside the
. $pee = preg_replace( '|
]*)>|i', '
', $pee ); $pee = str_replace( '
', '

', $pee ); // If an opening or closing block element tag is preceded by an opening

tag, remove it. $pee = preg_replace( '!

\s*(]*>)!', '$1', $pee ); // If an opening or closing block element tag is followed by a closing

tag, remove it. $pee = preg_replace( '!(]*>)\s*

!', '$1', $pee ); // Optionally insert line breaks. if ( $br ) { // Replace newlines that shouldn't be touched with a placeholder. $pee = preg_replace_callback( '/<(script|style|svg).*?<\/\\1>/s', '_autop_newline_preservation_helper', $pee ); // Normalize
$pee = str_replace( array( '
', '
' ), '
', $pee ); // Replace any new line characters that aren't preceded by a
with a
. $pee = preg_replace( '|(?)\s*\n|', "
\n", $pee ); // Replace newline placeholders with newlines. $pee = str_replace( '', "\n", $pee ); } // If a
tag is after an opening or closing block tag, remove it. $pee = preg_replace( '!(]*>)\s*
!', '$1', $pee ); // If a
tag is before a subset of opening or closing block tags, remove it. $pee = preg_replace( '!
(\s*]*>)!', '$1', $pee ); $pee = preg_replace( "|\n

$|", '

', $pee ); // Replace placeholder

 tags with their original content.
        if ( ! empty( $pre_tags ) ) {
            $pee = str_replace( array_keys( $pre_tags ), array_values( $pre_tags ), $pee );
        }
    
        // Restore newlines in all elements.
        if ( false !== strpos( $pee, '' ) ) {
            $pee = str_replace( array( '  ', '' ), "\n", $pee );
        }
    
        return $pee;
    }

    function _autop_newline_preservation_helper( $matches ) {
        return str_replace( "\n", '', $matches[0] );
    }

    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.
            foreach ( $replace_pairs as $needle => $replace ) {
            }
     
            // Loop through delimiters (elements) only.
            for ( $i = 1, $c = count( $textarr ); $i < $c; $i += 2 ) {
                if ( false !== strpos( $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 ( false !== strpos( $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;
    }

    function wp_html_split( $input ) {
        return preg_split( get_html_split_regex(), $input, -1, PREG_SPLIT_DELIM_CAPTURE );
    }

    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;
    }