X-Git-Url: https://scripts.mit.edu/gitweb/autoinstalls/wordpress.git/blobdiff_plain/874d2a2f468a0d1e69aab49b1fe2d9d79d3e1142..899389d1e4043331309c0433543419258b230b60:/wp-includes/formatting.php

diff --git a/wp-includes/formatting.php b/wp-includes/formatting.php
index e79043bc..acdc3d78 100644
--- a/wp-includes/formatting.php
+++ b/wp-includes/formatting.php
@@ -11,13 +11,13 @@
  * Replaces common plain text characters into formatted entities
  *
  * As an example,
- * <code>
- * 'cause today's effort makes it worth tomorrow's "holiday"...
- * </code>
+ *
+ *     'cause today's effort makes it worth tomorrow's "holiday" ...
+ *
  * Becomes:
- * <code>
- * &#8217;cause today&#8217;s effort makes it worth tomorrow&#8217;s &#8220;holiday&#8221;&#8230;
- * </code>
+ *
+ *     &#8217;cause today&#8217;s effort makes it worth tomorrow&#8217;s &#8220;holiday&#8221; &#8230;
+ *
  * Code within certain html blocks are skipped.
  *
  * @since 0.71
@@ -86,11 +86,11 @@ function wptexturize($text, $reset = false) {
 
 		// if a plugin has provided an autocorrect array, use it
 		if ( isset($wp_cockneyreplace) ) {
-			$cockney = array_keys($wp_cockneyreplace);
-			$cockneyreplace = array_values($wp_cockneyreplace);
+			$cockney = array_keys( $wp_cockneyreplace );
+			$cockneyreplace = array_values( $wp_cockneyreplace );
 		} elseif ( "'" != $apos ) { // Only bother if we're doing a replacement.
-			$cockney = array( "'tain't", "'twere", "'twas", "'tis", "'twill", "'til", "'bout", "'nuff", "'round", "'cause" );
-			$cockneyreplace = array( $apos . "tain" . $apos . "t", $apos . "twere", $apos . "twas", $apos . "tis", $apos . "twill", $apos . "til", $apos . "bout", $apos . "nuff", $apos . "round", $apos . "cause" );
+			$cockney = array( "'tain't", "'twere", "'twas", "'tis", "'twill", "'til", "'bout", "'nuff", "'round", "'cause", "'em" );
+			$cockneyreplace = array( $apos . "tain" . $apos . "t", $apos . "twere", $apos . "twas", $apos . "tis", $apos . "twill", $apos . "til", $apos . "bout", $apos . "nuff", $apos . "round", $apos . "cause", $apos . "em" );
 		} else {
 			$cockney = $cockneyreplace = array();
 		}
@@ -174,9 +174,9 @@ function wptexturize($text, $reset = false) {
 
 		// Dashes and spaces
 		$dynamic[ '/---/' ] = $em_dash;
-		$dynamic[ '/(?<=' . $spaces . ')--(?=' . $spaces . ')/' ] = $em_dash;
+		$dynamic[ '/(?<=^|' . $spaces . ')--(?=$|' . $spaces . ')/' ] = $em_dash;
 		$dynamic[ '/(?<!xn)--/' ] = $en_dash;
-		$dynamic[ '/(?<=' . $spaces . ')-(?=' . $spaces . ')/' ] = $en_dash;
+		$dynamic[ '/(?<=^|' . $spaces . ')-(?=$|' . $spaces . ')/' ] = $en_dash;
 
 		$dynamic_characters['dash'] = array_keys( $dynamic );
 		$dynamic_replacements['dash'] = array_values( $dynamic );
@@ -215,26 +215,30 @@ function wptexturize($text, $reset = false) {
 		.     '-(?!->)' // Dash not followed by end of comment.
 		.     '[^\-]*+' // Consume non-dashes.
 		. ')*+'         // Loop possessively.
-		. '-->';        // End of comment.
-
-	$regex =  '/('			// Capture the entire match.
-		.	'<'		// Find start of element.
-		.	'(?(?=!--)'	// Is this a comment?
-		.		$comment_regex	// Find end of comment
-		.	'|'
-		.		'[^>]+>'	// Find end of element
-		.	')'
+		. '(?:-->)?';   // End of comment. If not found, match all input.
+
+	$shortcode_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.
 		. '|'
-		.	'\['		// 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 ]]
+		.     '<[^\[\]>]*>' // HTML elements permitted. Prevents matching ] before >.
+		. ')*+'             // Possessive critical.
+		. '\]'              // Find end of shortcode.
+		. '\]?';            // Shortcodes may end with ]]
+
+	$regex =
+		  '/('                   // Capture the entire match.
+		.     '<'                // Find start of element.
+		.     '(?(?=!--)'        // Is this a comment?
+		.         $comment_regex // Find end of comment.
+		.     '|'
+		.         '[^>]*>'       // Find end of element.
+		.     ')'
+		. '|'
+		.     $shortcode_regex   // Find shortcodes.
 		. ')/s';
 
 	$textarr = preg_split( $regex, $text, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
@@ -242,30 +246,31 @@ function wptexturize($text, $reset = false) {
 	foreach ( $textarr as &$curl ) {
 		// Only call _wptexturize_pushpop_element if $curl is a delimiter.
 		$first = $curl[0];
-		if ( '<' === $first && '>' === substr( $curl, -1 ) ) {
-			// This is an HTML delimiter.
+		if ( '<' === $first && '<!--' === substr( $curl, 0, 4 ) ) {
+			// This is an HTML comment delimeter.
 
-			if ( '<!--' !== substr( $curl, 0, 4 ) ) {
-				_wptexturize_pushpop_element( $curl, $no_texturize_tags_stack, $no_texturize_tags );
-			}
+			continue;
+
+		} elseif ( '<' === $first && '>' === substr( $curl, -1 ) ) {
+			// This is an HTML element delimiter.
+
+			_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 && 1 === preg_match( '/^\[\/?' . $tagregexp . '(?:[^\[\]<>]+|<[^\[\]>]*>)*+\]$/', $curl ) ) {
+		} elseif ( '[' === $first && 1 === preg_match( '/^' . $shortcode_regex . '$/', $curl ) ) {
 			// This is a shortcode delimiter.
 
-			_wptexturize_pushpop_element( $curl, $no_texturize_shortcodes_stack, $no_texturize_shortcodes );
-
-		} elseif ( '[' === $first && 1 === preg_match( '/^\[[\/\[]?' . $tagregexp . '(?:[^\[\]<>]+|<[^\[\]>]*>)*+\]\]?$/', $curl ) ) {
-			// This is an escaped shortcode delimiter.
-
-			// Do not texturize.
-			// Do not push to the shortcodes stack.
-
-			continue;
+			if ( '[[' !== substr( $curl, 0, 2 ) && ']]' !== substr( $curl, -2 ) ) {
+				// 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( $no_texturize_tags_stack ) ) {
 			// This is neither a delimiter, nor is this content inside of no_texturize pairs.  Do texturize.
@@ -283,9 +288,9 @@ function wptexturize($text, $reset = false) {
 			}
 
 			// 9x9 (times), but never 0x9999
-			if ( 1 === preg_match( '/(?<=\d)x-?\d/', $curl ) ) {
+			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 );
+				$curl = preg_replace( '/\b(\d(?(?<=0)[\d\.,]+|[\d\.,]*))x(\d[\d\.,]*)\b/', '$1&#215;$2', $curl );
 			}
 		}
 	}
@@ -307,7 +312,7 @@ function wptexturize($text, $reset = false) {
  * @since 2.9.0
  * @access private
  *
- * @param string $text Text to check. Must be a tag like <html> or [shortcode].
+ * @param string $text Text to check. Must be a tag like `<html>` or `[shortcode]`.
  * @param array $stack List of open tag elements.
  * @param array $disabled_elements The tag names to match against. Spaces are not allowed in tag names.
  */
@@ -326,7 +331,7 @@ function _wptexturize_pushpop_element($text, &$stack, $disabled_elements) {
 
 	// Parse out the tag name.
 	$space = strpos( $text, ' ' );
-	if ( FALSE === $space ) {
+	if ( false === $space ) {
 		$space = -1;
 	} else {
 		$space -= $name_offset;
@@ -355,14 +360,14 @@ function _wptexturize_pushpop_element($text, &$stack, $disabled_elements) {
  * 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'.
+ * 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 $pee The text which has to be formatted.
- * @param bool $br Optional. If set, this will convert all remaining line-breaks after paragraphing. Default true.
+ * @param bool   $br  Optional. If set, this will convert all remaining line-breaks
+ *                    after paragraphing. Default true.
  * @return string Text which has been converted into correct paragraph tags.
  */
 function wpautop($pee, $br = true) {
@@ -371,8 +376,13 @@ function wpautop($pee, $br = true) {
 	if ( trim($pee) === '' )
 		return '';
 
-	$pee = $pee . "\n"; // just to make things a little easier, pad the end
+	// Just to make things a little easier, pad the end.
+	$pee = $pee . "\n";
 
+	/*
+	 * Pre tags shouldn't be touched by autop.
+	 * Replace pre tags with placeholders and bring them back after autop.
+	 */
 	if ( strpos($pee, '<pre') !== false ) {
 		$pee_parts = explode( '</pre>', $pee );
 		$last_pee = array_pop($pee_parts);
@@ -397,62 +407,102 @@ function wpautop($pee, $br = true) {
 
 		$pee .= $last_pee;
 	}
-
+	// Change multiple <br>s into two line breaks, which will turn into paragraphs.
 	$pee = preg_replace('|<br />\s*<br />|', "\n\n", $pee);
-	// Space things out a little
-	$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|form|map|area|blockquote|address|math|style|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|details|menu|summary)';
+
+	$allblocks = '(?:table|thead|tfoot|caption|col|colgroup|tbody|tr|td|th|div|dl|dd|dt|ul|ol|li|pre|form|map|area|blockquote|address|math|style|p|h[1-6]|hr|fieldset|legend|section|article|aside|hgroup|header|footer|nav|figure|figcaption|details|menu|summary)';
+
+	// Add a single line break above block-level opening tags.
 	$pee = preg_replace('!(<' . $allblocks . '[^>]*>)!', "\n$1", $pee);
+
+	// Add a double line break below block-level closing tags.
 	$pee = preg_replace('!(</' . $allblocks . '>)!', "$1\n\n", $pee);
-	$pee = str_replace(array("\r\n", "\r"), "\n", $pee); // cross-platform newlines
 
+	// Standardize newline characters to "\n".
+	$pee = str_replace(array("\r\n", "\r"), "\n", $pee); 
+
+	// Collapse line breaks before and after <option> elements so they don't get autop'd.
 	if ( strpos( $pee, '<option' ) !== false ) {
-		// no P/BR around option
 		$pee = preg_replace( '|\s*<option|', '<option', $pee );
 		$pee = preg_replace( '|</option>\s*|', '</option>', $pee );
 	}
 
+	/*
+	 * Collapse line breaks inside <object> elements, before <param> and <embed> elements
+	 * so they don't get autop'd.
+	 */
 	if ( strpos( $pee, '</object>' ) !== false ) {
-		// no P/BR around param and embed
 		$pee = preg_replace( '|(<object[^>]*>)\s*|', '$1', $pee );
 		$pee = preg_replace( '|\s*</object>|', '</object>', $pee );
 		$pee = preg_replace( '%\s*(</?(?:param|embed)[^>]*>)\s*%', '$1', $pee );
 	}
 
+	/*
+	 * Collapse line breaks inside <audio> and <video> elements,
+	 * before and after <source> and <track> elements.
+	 */
 	if ( strpos( $pee, '<source' ) !== false || strpos( $pee, '<track' ) !== false ) {
-		// no P/BR around source and track
 		$pee = preg_replace( '%([<\[](?:audio|video)[^>\]]*[>\]])\s*%', '$1', $pee );
 		$pee = preg_replace( '%\s*([<\[]/(?:audio|video)[>\]])%', '$1', $pee );
 		$pee = preg_replace( '%\s*(<(?:source|track)[^>]*>)\s*%', '$1', $pee );
 	}
 
-	$pee = preg_replace("/\n\n+/", "\n\n", $pee); // take care of duplicates
-	// make paragraphs, including one at the end
+	// Remove more than two contiguous line breaks.
+	$pee = preg_replace("/\n\n+/", "\n\n", $pee);
+
+	// Split up the contents into an array of strings, separated by double line breaks.
 	$pees = preg_split('/\n\s*\n/', $pee, -1, PREG_SPLIT_NO_EMPTY);
+
+	// Reset $pee prior to rebuilding.
 	$pee = '';
 
+	// Rebuild the content as a string, wrapping every bit with a <p>.
 	foreach ( $pees as $tinkle ) {
 		$pee .= '<p>' . trim($tinkle, "\n") . "</p>\n";
 	}
 
-	$pee = preg_replace('|<p>\s*</p>|', '', $pee); // under certain strange conditions it could create a P of entirely whitespace
+	// Under certain strange conditions it could create a P of entirely whitespace.
+	$pee = preg_replace('|<p>\s*</p>|', '', $pee); 
+
+	// Add a closing <p> inside <div>, <address>, or <form> tag if missing.
 	$pee = preg_replace('!<p>([^<]+)</(div|address|form)>!', "<p>$1</p></$2>", $pee);
-	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee); // don't pee all over a tag
-	$pee = preg_replace("|<p>(<li.+?)</p>|", "$1", $pee); // problem with nested lists
+	
+	// If an opening or closing block element tag is wrapped in a <p>, unwrap it.
+	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee); 
+	
+	// In some cases <li> may get wrapped in <p>, fix them.
+	$pee = preg_replace("|<p>(<li.+?)</p>|", "$1", $pee); 
+	
+	// If a <blockquote> is wrapped with a <p>, move it inside the <blockquote>.
 	$pee = preg_replace('|<p><blockquote([^>]*)>|i', "<blockquote$1><p>", $pee);
 	$pee = str_replace('</blockquote></p>', '</p></blockquote>', $pee);
+	
+	// If an opening or closing block element tag is preceded by an opening <p> tag, remove it.
 	$pee = preg_replace('!<p>\s*(</?' . $allblocks . '[^>]*>)!', "$1", $pee);
+	
+	// If an opening or closing block element tag is followed by a closing <p> tag, remove it.
 	$pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*</p>!', "$1", $pee);
 
+	// Optionally insert line breaks.
 	if ( $br ) {
+		// Replace newlines that shouldn't be touched with a placeholder.
 		$pee = preg_replace_callback('/<(script|style).*?<\/\\1>/s', '_autop_newline_preservation_helper', $pee);
-		$pee = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $pee); // optionally make line breaks
+
+		// Replace any new line characters that aren't preceded by a <br /> with a <br />.
+		$pee = preg_replace('|(?<!<br />)\s*\n|', "<br />\n", $pee); 
+
+		// Replace newline placeholders with newlines.
 		$pee = str_replace('<WPPreserveNewline />', "\n", $pee);
 	}
 
+	// If a <br /> tag is after an opening or closing block tag, remove it.
 	$pee = preg_replace('!(</?' . $allblocks . '[^>]*>)\s*<br />!', "$1", $pee);
+	
+	// If a <br /> tag is before a subset of opening or closing block tags, remove it.
 	$pee = preg_replace('!<br />(\s*</?(?:p|li|div|dl|dd|dt|th|pre|td|ul|ol)[^>]*>)!', '$1', $pee);
 	$pee = preg_replace( "|\n</p>$|", '</p>', $pee );
 
+	// Replace placeholder <pre> tags with their original content.
 	if ( !empty($pre_tags) )
 		$pee = str_replace(array_keys($pre_tags), array_values($pre_tags), $pee);
 
@@ -475,7 +525,7 @@ function _autop_newline_preservation_helper( $matches ) {
 /**
  * Don't auto-p wrap shortcodes that stand alone
  *
- * Ensures that shortcodes are not wrapped in <<p>>...<</p>>.
+ * Ensures that shortcodes are not wrapped in `<p>...</p>`.
  *
  * @since 2.9.0
  *
@@ -545,14 +595,14 @@ function seems_utf8($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; $j++) { # n bytes matching 10bbbbbb follow ?
+		if ($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[$i]) & 0xC0) != 0x80))
 				return false;
 		}
@@ -572,7 +622,7 @@ function seems_utf8($str) {
  * @access private
  *
  * @param string $string The text which is to be encoded.
- * @param mixed $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. 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 int $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. 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 string $charset Optional. The character encoding of the string. Default is false.
  * @param boolean $double_encode Optional. Whether to encode existing html entities. Default is false.
  * @return string The encoded text with HTML entities.
@@ -628,9 +678,9 @@ function _wp_specialchars( $string, $quote_style = ENT_NOQUOTES, $charset = fals
 		// Now re-encode everything except &entity;
 		$string = preg_split( '/(&#?x?[0-9a-z]+;)/i', $string, -1, PREG_SPLIT_DELIM_CAPTURE );
 
-		for ( $i = 0; $i < count( $string ); $i += 2 )
+		for ( $i = 0, $c = count( $string ); $i < $c; $i += 2 ) {
 			$string[$i] = @htmlspecialchars( $string[$i], $quote_style, $charset );
-
+		}
 		$string = implode( '', $string );
 	}
 
@@ -780,21 +830,27 @@ function utf8_uri_encode( $utf8_string, $length = 0 ) {
 			$unicode .= chr($value);
 			$unicode_length++;
 		} else {
-			if ( count( $values ) == 0 ) $num_octets = ( $value < 224 ) ? 2 : 3;
+			if ( count( $values ) == 0 ) {
+				if ( $value < 224 ) {
+					$num_octets = 2;
+				} elseif ( $value < 240 ) {
+					$num_octets = 3;
+				} else {
+					$num_octets = 4;
+				}
+			}
 
 			$values[] = $value;
 
 			if ( $length && ( $unicode_length + ($num_octets * 3) ) > $length )
 				break;
 			if ( count( $values ) == $num_octets ) {
-				if ($num_octets == 3) {
-					$unicode .= '%' . dechex($values[0]) . '%' . dechex($values[1]) . '%' . dechex($values[2]);
-					$unicode_length += 9;
-				} else {
-					$unicode .= '%' . dechex($values[0]) . '%' . dechex($values[1]);
-					$unicode_length += 6;
+				for ( $j = 0; $j < $num_octets; $j++ ) {
+					$unicode .= '%' . dechex( $values[ $j ] );
 				}
 
+				$unicode_length += $num_octets * 3;
+
 				$values = array();
 				$num_octets = 1;
 			}
@@ -1017,6 +1073,7 @@ function remove_accents($string) {
 
 		$string = strtr($string, $chars);
 	} else {
+		$chars = array();
 		// Assume ISO-8859-1 if not UTF-8
 		$chars['in'] = chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
 			.chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
@@ -1032,6 +1089,7 @@ function remove_accents($string) {
 		$chars['out'] = "EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy";
 
 		$string = strtr($string, $chars['in'], $chars['out']);
+		$double_chars = array();
 		$double_chars['in'] = array(chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254));
 		$double_chars['out'] = array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th');
 		$string = str_replace($double_chars['in'], $double_chars['out'], $string);
@@ -1067,10 +1125,10 @@ function sanitize_file_name( $filename ) {
 	 */
 	$special_chars = apply_filters( 'sanitize_file_name_chars', $special_chars, $filename_raw );
 	$filename = preg_replace( "#\x{00a0}#siu", ' ', $filename );
-	$filename = str_replace($special_chars, '', $filename);
+	$filename = str_replace( $special_chars, '', $filename );
 	$filename = str_replace( array( '%20', '+' ), '-', $filename );
-	$filename = preg_replace('/[\s-]+/', '-', $filename);
-	$filename = trim($filename, '.-_');
+	$filename = preg_replace( '/[\r\n\t -]+/', '-', $filename );
+	$filename = trim( $filename, '.-_' );
 
 	// Split the filename into a base and extension[s]
 	$parts = explode('.', $filename);
@@ -1229,7 +1287,6 @@ function sanitize_title( $title, $fallback_title = '', $context = 'save' ) {
  * Used for querying the database for a value from URL.
  *
  * @since 3.1.0
- * @uses sanitize_title()
  *
  * @param string $title The string to be sanitized.
  * @return string The sanitized string.
@@ -1305,21 +1362,23 @@ function sanitize_title_with_dashes( $title, $raw_title = '', $context = 'displa
 }
 
 /**
- * Ensures a string is a valid SQL order by clause.
+ * Ensures a string is a valid SQL 'order by' clause.
  *
- * Accepts one or more columns, with or without ASC/DESC, and also accepts
- * RAND().
+ * Accepts one or more columns, with or without a sort order (ASC / DESC).
+ * e.g. 'column_1', 'column_1, column_2', 'column_1 ASC, column_2 DESC' etc.
+ *
+ * Also accepts 'RAND()'.
  *
  * @since 2.5.1
  *
- * @param string $orderby Order by string to be checked.
- * @return string|bool Returns the order by clause if it is a match, false otherwise.
+ * @param string $orderby Order by clause to be validated.
+ * @return string|bool Returns $orderby if valid, false otherwise.
  */
-function sanitize_sql_orderby( $orderby ){
-	preg_match('/^\s*([a-z0-9_]+(\s+(ASC|DESC))?(\s*,\s*|\s*$))+|^\s*RAND\(\s*\)\s*$/i', $orderby, $obmatches);
-	if ( !$obmatches )
-		return false;
-	return $orderby;
+function sanitize_sql_orderby( $orderby ) {
+	if ( preg_match( '/^\s*(([a-z0-9_]+|`[a-z0-9_]+`)(\s+(ASC|DESC))?\s*(,\s*(?=[a-z0-9_`])|$))+$/i', $orderby ) || preg_match( '/^\s*RAND\(\s*\)\s*$/i', $orderby ) ) {
+		return $orderby;
+	}
+	return false;
 }
 
 /**
@@ -1362,7 +1421,7 @@ function sanitize_html_class( $class, $fallback = '' ) {
 /**
  * Converts a number of characters from a string.
  *
- * Metadata tags <<title>> and <<category>> are removed, <<br>> and <<hr>> are
+ * Metadata tags `<title>` and `<category>` are removed, `<br>` and `<hr>` are
  * converted into correct XHTML and Unicode characters are converted to the
  * valid range.
  *
@@ -1496,7 +1555,7 @@ function force_balance_tags( $text ) {
 				// or close to be safe $tag = '/' . $tag;
 			}
 			// if stacktop value = tag close value then pop
-			else if ( $tagstack[$stacksize - 1] == $tag ) { // found closing tag
+			elseif ( $tagstack[$stacksize - 1] == $tag ) { // found closing tag
 				$tag = '</' . $tag . '>'; // Close Tag
 				// Pop
 				array_pop( $tagstack );
@@ -1753,7 +1812,7 @@ function rawurlencode_deep( $value ) {
  */
 function antispambot( $email_address, $hex_encoding = 0 ) {
 	$email_no_spam_address = '';
-	for ( $i = 0; $i < strlen( $email_address ); $i++ ) {
+	for ( $i = 0, $len = strlen( $email_address ); $i < $len; $i++ ) {
 		$j = rand( 0, 1 + $hex_encoding );
 		if ( $j == 0 ) {
 			$email_no_spam_address .= '&#' . ord( $email_address[$i] ) . ';';
@@ -1931,19 +1990,17 @@ function make_clickable( $text ) {
  *
  * Input string must have no null characters (or eventual transformations on output chunks must not care about null characters)
  *
- * <code>
- * _split_str_by_whitespace( "1234 67890 1234 67890a cd 1234   890 123456789 1234567890a    45678   1 3 5 7 90 ", 10 ) ==
- * array (
- *   0 => '1234 67890 ',  // 11 characters: Perfect split
- *   1 => '1234 ',        //  5 characters: '1234 67890a' was too long
- *   2 => '67890a cd ',   // 10 characters: '67890a cd 1234' was too long
- *   3 => '1234   890 ',  // 11 characters: Perfect split
- *   4 => '123456789 ',   // 10 characters: '123456789 1234567890a' was too long
- *   5 => '1234567890a ', // 12 characters: Too long, but no inner whitespace on which to split
- *   6 => '   45678   ',  // 11 characters: Perfect split
- *   7 => '1 3 5 7 9',    //  9 characters: End of $string
- * );
- * </code>
+ *     _split_str_by_whitespace( "1234 67890 1234 67890a cd 1234   890 123456789 1234567890a    45678   1 3 5 7 90 ", 10 ) ==
+ *     array (
+ *         0 => '1234 67890 ',  // 11 characters: Perfect split
+ *         1 => '1234 ',        //  5 characters: '1234 67890a' was too long
+ *         2 => '67890a cd ',   // 10 characters: '67890a cd 1234' was too long
+ *         3 => '1234   890 ',  // 11 characters: Perfect split
+ *         4 => '123456789 ',   // 10 characters: '123456789 1234567890a' was too long
+ *         5 => '1234567890a ', // 12 characters: Too long, but no inner whitespace on which to split
+ *         6 => '   45678   ',  // 11 characters: Perfect split
+ *         7 => '1 3 5 7 90 ',  // 11 characters: End of $string
+ *     );
  *
  * @since 3.4.0
  * @access private
@@ -2017,7 +2074,7 @@ function wp_rel_nofollow_callback( $matches ) {
  *
  * Callback handler for {@link convert_smilies()}.
  * Looks up one smiley code in the $wpsmiliestrans global array and returns an
- * <img> string for that smiley.
+ * `<img>` string for that smiley.
  *
  * @global array $wpsmiliestrans
  * @since 2.8.0
@@ -2034,6 +2091,15 @@ function translate_smiley( $matches ) {
 	$smiley = trim( reset( $matches ) );
 	$img = $wpsmiliestrans[ $smiley ];
 
+	$matches = array();
+	$ext = preg_match( '/\.([^.]+)$/', $img, $matches ) ? strtolower( $matches[1] ) : false;
+	$image_exts = array( 'jpg', 'jpeg', 'jpe', 'gif', 'png' );
+
+	// Don't convert smilies that aren't images - they're probably emoji.
+	if ( ! in_array( $ext, $image_exts ) ) {
+		return $img;
+	}
+
 	/**
 	 * Filter the Smiley image URL before it's used in the image element.
 	 *
@@ -2045,7 +2111,7 @@ function translate_smiley( $matches ) {
 	 */
 	$src_url = apply_filters( 'smilies_src', includes_url( "images/smilies/$img" ), $img, site_url() );
 
-	return sprintf( '<img src="%s" alt="%s" class="wp-smiley" />', esc_url( $src_url ), esc_attr( $smiley ) );
+	return sprintf( '<img src="%s" alt="%s" class="wp-smiley" style="height: 1em; max-height: 1em;" />', esc_url( $src_url ), esc_attr( $smiley ) );
 }
 
 /**
@@ -2217,7 +2283,7 @@ function wp_iso_descrambler($string) {
  * @access private
  *
  * @param array $match The preg_replace_callback matches array
- * @return array Converted chars
+ * @return string Converted chars
  */
 function _wp_iso_convert( $match ) {
 	return chr( hexdec( strtolower( $match[1] ) ) );
@@ -2233,7 +2299,6 @@ function _wp_iso_convert( $match ) {
  *
  * @since 1.2.0
  *
- * @uses get_option() to retrieve the value of 'gmt_offset'.
  * @param string $string The date to be converted.
  * @param string $format The format string for the returned date (default is Y-m-d H:i:s)
  * @return string GMT version of the date provided.
@@ -2334,7 +2399,7 @@ function iso8601_to_datetime($date_string, $timezone = 'user') {
 
 		return gmdate('Y-m-d H:i:s', $timestamp);
 
-	} else if ($timezone == 'user') {
+	} elseif ($timezone == 'user') {
 		return preg_replace('#([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2}):([0-9]{2}):([0-9]{2})(Z|[\+|\-][0-9]{2,4}){0,1}#', '$1-$2-$3 $4:$5:$6', $date_string);
 	}
 }
@@ -3026,8 +3091,6 @@ function esc_sql( $data ) {
  * is applied to the returned cleaned URL.
  *
  * @since 2.8.0
- * @uses wp_kses_bad_protocol() To only permit protocols in the URL set
- *		via $protocols or the common ones set in the function.
  *
  * @param string $url The URL to be cleaned.
  * @param array $protocols Optional. An array of acceptable protocols.
@@ -3085,7 +3148,6 @@ function esc_url( $url, $protocols = null, $_context = 'display' ) {
  * Performs esc_url() for database usage.
  *
  * @since 2.8.0
- * @uses esc_url()
  *
  * @param string $url The URL to be cleaned.
  * @param array $protocols An array of acceptable protocols.
@@ -3242,12 +3304,13 @@ function tag_escape($tag_name) {
  * beginning, so it isn't a true relative link, but from the web root base.
  *
  * @since 2.1.0
+ * @since 4.1.0 Support was added for relative URLs.
  *
  * @param string $link Full URL path.
  * @return string Absolute path.
  */
 function wp_make_link_relative( $link ) {
-	return preg_replace( '|https?://[^/]+(/.*)|i', '$1', $link );
+	return preg_replace( '|^(https?:)?//[^/]+(/.*)|i', '$2', $link );
 }
 
 /**
@@ -3263,10 +3326,12 @@ function wp_make_link_relative( $link ) {
  * @return string Sanitized value.
  */
 function sanitize_option($option, $value) {
+	global $wpdb;
 
 	switch ( $option ) {
 		case 'admin_email' :
 		case 'new_admin_email' :
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			$value = sanitize_email( $value );
 			if ( ! is_email( $value ) ) {
 				$value = get_option( $option ); // Resets option to stored value in the case of failed sanitization
@@ -3315,6 +3380,7 @@ function sanitize_option($option, $value) {
 
 		case 'blogdescription':
 		case 'blogname':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			$value = wp_kses_post( $value );
 			$value = esc_html( $value );
 			break;
@@ -3337,6 +3403,7 @@ function sanitize_option($option, $value) {
 		case 'mailserver_login':
 		case 'mailserver_pass':
 		case 'upload_path':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			$value = strip_tags( $value );
 			$value = wp_kses_data( $value );
 			break;
@@ -3353,6 +3420,7 @@ function sanitize_option($option, $value) {
 			break;
 
 		case 'siteurl':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			if ( (bool)preg_match( '#http(s?)://(.+)#i', $value) ) {
 				$value = esc_url_raw($value);
 			} else {
@@ -3363,6 +3431,7 @@ function sanitize_option($option, $value) {
 			break;
 
 		case 'home':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			if ( (bool)preg_match( '#http(s?)://(.+)#i', $value) ) {
 				$value = esc_url_raw($value);
 			} else {
@@ -3383,6 +3452,7 @@ function sanitize_option($option, $value) {
 			break;
 
 		case 'illegal_names':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			if ( ! is_array( $value ) )
 				$value = explode( ' ', $value );
 
@@ -3394,6 +3464,7 @@ function sanitize_option($option, $value) {
 
 		case 'limited_email_domains':
 		case 'banned_email_domains':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			if ( ! is_array( $value ) )
 				$value = explode( "\n", $value );
 
@@ -3420,6 +3491,7 @@ function sanitize_option($option, $value) {
 		case 'permalink_structure':
 		case 'category_base':
 		case 'tag_base':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			$value = esc_url_raw( $value );
 			$value = str_replace( 'http://', '', $value );
 			break;
@@ -3431,6 +3503,7 @@ function sanitize_option($option, $value) {
 
 		case 'moderation_keys':
 		case 'blacklist_keys':
+			$value = $wpdb->strip_invalid_text_for_column( $wpdb->options, 'option_value', $value );
 			$value = explode( "\n", $value );
 			$value = array_filter( array_map( 'trim', $value ) );
 			$value = array_unique( $value );
@@ -3481,7 +3554,6 @@ function wp_parse_str( $string, &$array ) {
  *
  * KSES already converts lone greater than signs.
  *
- * @uses wp_pre_kses_less_than_callback in the callback function.
  * @since 2.3.0
  *
  * @param string $text Text to be converted.
@@ -3494,7 +3566,6 @@ function wp_pre_kses_less_than( $text ) {
 /**
  * Callback function used by preg_replace.
  *
- * @uses esc_html to format the $matches text.
  * @since 2.3.0
  *
  * @param array $matches Populated by matches to preg_replace.
@@ -3513,7 +3584,7 @@ function wp_pre_kses_less_than_callback( $matches ) {
  * @link http://www.php.net/sprintf
  *
  * @param string $pattern The string which formatted args are inserted.
- * @param mixed $args,... Arguments to be formatted into the $pattern string.
+ * @param mixed  $args ,... Arguments to be formatted into the $pattern string.
  * @return string The formatted string.
  */
 function wp_sprintf( $pattern ) {
@@ -3697,17 +3768,18 @@ function _links_add_base($m) {
 	return $m[1] . '=' . $m[2] .
 		( preg_match( '#^(\w{1,20}):#', $m[3], $protocol ) && in_array( $protocol[1], wp_allowed_protocols() ) ?
 			$m[3] :
-			path_join( $_links_add_base, $m[3] ) )
+			WP_HTTP::make_absolute_url( $m[3], $_links_add_base )
+		)
 		. $m[2];
 }
 
 /**
  * Adds a Target attribute to all links in passed content.
  *
- * This function by default only applies to <a> tags, however this can be
+ * This function by default only applies to `<a>` tags, however this can be
  * modified by the 3rd param.
  *
- * <b>NOTE:</b> Any current target attributed will be stripped and replaced.
+ * *NOTE:* Any current target attributed will be stripped and replaced.
  *
  * @since 2.7.0
  *
@@ -3758,7 +3830,7 @@ function normalize_whitespace( $str ) {
  * Properly strip all HTML tags including script and style
  *
  * This differs from strip_tags() because it removes the contents of
- * the <script> and <style> tags. E.g. strip_tags( '<script>something</script>' )
+ * the `<script>` and `<style>` tags. E.g. `strip_tags( '<script>something</script>' )`
  * will return 'something'. wp_strip_all_tags will return ''
  *
  * @since 2.9.0
@@ -4005,3 +4077,301 @@ function wp_spaces_regexp() {
 
 	return $spaces;
 }
+
+/**
+ * Print the important emoji-related styles.
+ *
+ * @since 4.2.0
+ */
+function print_emoji_styles() {
+	static $printed = false;
+
+	if ( $printed ) {
+		return;
+	}
+
+	$printed = true;
+?>
+<style type="text/css">
+img.wp-smiley,
+img.emoji {
+	display: inline !important;
+	border: none !important;
+	box-shadow: none !important;
+	height: 1em !important;
+	width: 1em !important;
+	margin: 0 .07em !important;
+	vertical-align: -0.1em !important;
+	background: none !important;
+	padding: 0 !important;
+}
+</style>
+<?php
+}
+
+function print_emoji_detection_script() {
+	global $wp_version;
+	static $printed = false;
+
+	if ( $printed ) {
+		return;
+	}
+
+	$printed = true;
+
+	$settings = array(
+		/**
+		 * Filter the URL where emoji images are hosted.
+		 *
+		 * @since 4.2.0
+		 *
+		 * @param string The emoji base URL.
+		 */
+		'baseUrl' => apply_filters( 'emoji_url', set_url_scheme( '//s.w.org/images/core/emoji/72x72/' ) ),
+
+		/**
+		 * Filter the extension of the emoji files.
+		 *
+		 * @since 4.2.0
+		 *
+		 * @param string The emoji extension. Default .png.
+		 */
+		'ext' => apply_filters( 'emoji_ext', '.png' ),
+	);
+
+	$version = 'ver=' . $wp_version;
+
+	if ( SCRIPT_DEBUG ) {
+		$settings['source'] = array(
+			/** This filter is documented in wp-includes/class.wp-scripts.php */
+			'wpemoji' => apply_filters( 'script_loader_src', includes_url( "js/wp-emoji.js?$version" ), 'wpemoji' ),
+			/** This filter is documented in wp-includes/class.wp-scripts.php */
+			'twemoji' => apply_filters( 'script_loader_src', includes_url( "js/twemoji.js?$version" ), 'twemoji' ),
+		);
+
+		?>
+		<script type="text/javascript">
+			window._wpemojiSettings = <?php echo wp_json_encode( $settings ); ?>;
+			<?php readfile( ABSPATH . WPINC . "/js/wp-emoji-loader.js" ); ?>
+		</script>
+		<?php
+	} else {
+		$settings['source'] = array(
+			/** This filter is documented in wp-includes/class.wp-scripts.php */
+			'concatemoji' => apply_filters( 'script_loader_src', includes_url( "js/wp-emoji-release.min.js?$version" ), 'concatemoji' ),
+		);
+
+		/*
+		 * If you're looking at a src version of this file, you'll see an "include"
+		 * statement below. This is used by the `grunt build` process to directly
+		 * include a minified version of wp-emoji-loader.js, instead of using the
+		 * readfile() method from above.
+		 *
+		 * If you're looking at a build version of this file, you'll see a string of
+		 * minified JavaScript. If you need to debug it, please turn on SCRIPT_DEBUG
+		 * and edit wp-emoji-loader.js directly.
+		 */
+		?>
+		<script type="text/javascript">
+			window._wpemojiSettings = <?php echo wp_json_encode( $settings ); ?>;
+			!function(a,b,c){function d(a){var c=b.createElement("canvas"),d=c.getContext&&c.getContext("2d");return d&&d.fillText?(d.textBaseline="top",d.font="600 32px Arial","flag"===a?(d.fillText(String.fromCharCode(55356,56812,55356,56807),0,0),c.toDataURL().length>3e3):(d.fillText(String.fromCharCode(55357,56835),0,0),0!==d.getImageData(16,16,1,1).data[0])):!1}function e(a){var c=b.createElement("script");c.src=a,c.type="text/javascript",b.getElementsByTagName("head")[0].appendChild(c)}var f,g;c.supports={simple:d("simple"),flag:d("flag")},c.DOMReady=!1,c.readyCallback=function(){c.DOMReady=!0},c.supports.simple&&c.supports.flag||(g=function(){c.readyCallback()},b.addEventListener?(b.addEventListener("DOMContentLoaded",g,!1),a.addEventListener("load",g,!1)):(a.attachEvent("onload",g),b.attachEvent("onreadystatechange",function(){"complete"===b.readyState&&c.readyCallback()})),f=c.source||{},f.concatemoji?e(f.concatemoji):f.wpemoji&&f.twemoji&&(e(f.twemoji),e(f.wpemoji)))}(window,document,window._wpemojiSettings);
+		</script>
+		<?php
+	}
+}
+
+/**
+ * Convert any 4 byte emoji in a string to their equivalent HTML entity.
+ *
+ * Currently, only Unicode 7 emoji are supported. Skin tone modifiers are allowed,
+ * all other Unicode 8 emoji will be added when the spec is finalised.
+ *
+ * This allows us to store emoji in a DB using the utf8 character set.
+ *
+ * @since 4.2.0
+ *
+ * @param string $content The content to encode.
+ * @return string The encoded content.
+ */
+function wp_encode_emoji( $content ) {
+	if ( function_exists( 'mb_convert_encoding' ) ) {
+		$regex = '/(
+		     \x23\xE2\x83\xA3               # Digits
+		     [\x30-\x39]\xE2\x83\xA3
+		   | \xF0\x9F[\x85-\x88][\xA6-\xBF] # Enclosed characters
+		   | \xF0\x9F[\x8C-\x97][\x80-\xBF] # Misc
+		   | \xF0\x9F\x98[\x80-\xBF]        # Smilies
+		   | \xF0\x9F\x99[\x80-\x8F]
+		   | \xF0\x9F\x9A[\x80-\xBF]        # Transport and map symbols
+		)/x';
+
+		$matches = array();
+		if ( preg_match_all( $regex, $content, $matches ) ) {
+			if ( ! empty( $matches[1] ) ) {
+				foreach( $matches[1] as $emoji ) {
+					/*
+					 * UTF-32's hex encoding is the same as HTML's hex encoding.
+					 * So, by converting the emoji from UTF-8 to UTF-32, we magically
+					 * get the correct hex encoding.
+					 */
+					$unpacked = unpack( 'H*', mb_convert_encoding( $emoji, 'UTF-32', 'UTF-8' ) );
+					if ( isset( $unpacked[1] ) ) {
+						$entity = '&#x' . ltrim( $unpacked[1], '0' ) . ';';
+						$content = str_replace( $emoji, $entity, $content );
+					}
+				}
+			}
+		}
+	}
+
+	return $content;
+}
+
+/**
+ * Convert emoji to a static img element.
+ *
+ * @since 4.2.0
+ *
+ * @param string $text The content to encode.
+ * @return string The encoded content.
+ */
+function wp_staticize_emoji( $text ) {
+	$text = wp_encode_emoji( $text );
+
+	/** This filter is documented in wp-includes/formatting.php */
+	$cdn_url = apply_filters( 'emoji_url', set_url_scheme( '//s.w.org/images/core/emoji/72x72/' ) );
+
+	/** This filter is documented in wp-includes/formatting.php */
+	$ext = apply_filters( 'emoji_ext', '.png' );
+
+	$output = '';
+	/*
+	 * HTML loop taken from smiley function, which was taken from texturize function.
+	 * It'll never be consolidated.
+	 *
+	 * First, capture the tags as well as in between.
+	 */
+	$textarr = preg_split( '/(<.*>)/U', $text, -1, PREG_SPLIT_DELIM_CAPTURE );
+	$stop = count( $textarr );
+
+	// Ignore processing of specific tags.
+	$tags_to_ignore = 'code|pre|style|script|textarea';
+	$ignore_block_element = '';
+
+	for ( $i = 0; $i < $stop; $i++ ) {
+		$content = $textarr[$i];
+
+		// If we're in an ignore block, wait until we find its closing tag.
+		if ( '' == $ignore_block_element && preg_match( '/^<(' . $tags_to_ignore . ')>/', $content, $matches ) )  {
+			$ignore_block_element = $matches[1];
+		}
+
+		// If it's not a tag and not in ignore block.
+		if ( '' ==  $ignore_block_element && strlen( $content ) > 0 && '<' != $content[0] ) {
+			$matches = array();
+			if ( preg_match_all( '/(&#x1f1(e[6-9a-f]|f[0-9a-f]);){2}/', $content, $matches ) ) {
+				if ( ! empty( $matches[0] ) ) {
+					foreach ( $matches[0] as $flag ) {
+						$chars = str_replace( array( '&#x', ';'), '', $flag );
+
+						list( $char1, $char2 ) = str_split( $chars, 5 );
+						$entity = sprintf( '<img src="%s" alt="%s" class="wp-smiley" style="height: 1em; max-height: 1em;" />', $cdn_url . $char1 . '-' . $char2 . $ext, html_entity_decode( $flag ) );
+
+						$content = str_replace( $flag, $entity, $content );
+					}
+				}
+			}
+
+			// Loosely match the Emoji Unicode range.
+			$regex = '/(&#x[2-3][0-9a-f]{3};|&#x1f[1-6][0-9a-f]{2};)/';
+
+			$matches = array();
+			if ( preg_match_all( $regex, $content, $matches ) ) {
+				if ( ! empty( $matches[1] ) ) {
+					foreach ( $matches[1] as $emoji ) {
+						$char = str_replace( array( '&#x', ';'), '', $emoji );
+						$entity = sprintf( '<img src="%s" alt="%s" class="wp-smiley" style="height: 1em; max-height: 1em;" />', $cdn_url . $char . $ext, html_entity_decode( $emoji ) );
+
+						$content = str_replace( $emoji, $entity, $content );
+					}
+				}
+			}
+		}
+
+		// Did we exit ignore block.
+		if ( '' != $ignore_block_element && '</' . $ignore_block_element . '>' == $content )  {
+			$ignore_block_element = '';
+		}
+
+		$output .= $content;
+	}
+
+	return $output;
+}
+
+/**
+ * Convert emoji in emails into static images.
+ *
+ * @since 4.2.0
+ *
+ * @param array $mail The email data array.
+ * @return array The email data array, with emoji in the message staticized.
+ */
+function wp_staticize_emoji_for_email( $mail ) {
+	if ( ! isset( $mail['message'] ) ) {
+		return $mail;
+	}
+
+	/*
+	 * We can only transform the emoji into images if it's a text/html email.
+	 * To do that, here's a cut down version of the same process that happens
+	 * in wp_mail() - get the Content-Type from the headers, if there is one,
+	 * then pass it through the wp_mail_content_type filter, in case a plugin
+	 * is handling changing the Content-Type.
+	 */
+	$headers = array();
+	if ( isset( $mail['headers'] ) ) {
+		if ( is_array( $mail['headers'] ) ) {
+			$headers = $mail['headers'];
+		} else {
+			$headers = explode( "\n", str_replace( "\r\n", "\n", $mail['headers'] ) );
+		}
+	}
+
+	foreach ( $headers as $header ) {
+		if ( strpos($header, ':') === false ) {
+			continue;
+		}
+
+		// Explode them out.
+		list( $name, $content ) = explode( ':', trim( $header ), 2 );
+
+		// Cleanup crew.
+		$name    = trim( $name    );
+		$content = trim( $content );
+
+		if ( 'content-type' === strtolower( $name ) ) {
+			if ( strpos( $content, ';' ) !== false ) {
+				list( $type, $charset ) = explode( ';', $content );
+				$content_type = trim( $type );
+			} else {
+				$content_type = trim( $content );
+			}
+			break;
+		}
+	}
+
+	// Set Content-Type if we don't have a content-type from the input headers.
+	if ( ! isset( $content_type ) ) {
+		$content_type = 'text/plain';
+	}
+
+	/** This filter is documented in wp-includes/pluggable.php */
+	$content_type = apply_filters( 'wp_mail_content_type', $content_type );
+
+	if ( 'text/html' === $content_type ) {
+		$mail['message'] = wp_staticize_emoji( $mail['message'] );
+	}
+
+	return $mail;
+}