Index: wp-includes/formatting.php
===================================================================
--- wp-includes/formatting.php	(revision 25954)
+++ wp-includes/formatting.php	(working copy)
@@ -33,6 +33,10 @@
 
 	// No need to set up these static variables more than once
 	if ( ! isset( $static_characters ) ) {
+		// Spaces include new lines, tabs, and the UTF-8 nbsp.
+		// Replaces the PCRE \s sequence per ticket #22692.
+		$spaces = apply_filters( 'texturize_spaces_regex', '[\r\n\t ]|\xC2\xA0' );
+
 		/* translators: opening curly double quote */
 		$opening_quote = _x( '“', 'opening curly double quote' );
 		/* translators: closing curly double quote */
@@ -73,27 +77,43 @@
 		$static_characters = array_merge( array( '---', ' -- ', '--', ' - ', 'xn–', '...', '``', '\'\'', ' (tm)' ), $cockney );
 		$static_replacements = array_merge( array( $em_dash, ' ' . $em_dash . ' ', $en_dash, ' ' . $en_dash . ' ', 'xn--', '…', $opening_quote, $closing_quote, ' ™' ), $cockneyreplace );
 
+		// Pattern-based replacements of static characters.
 		$dynamic = array();
-		if ( "'" != $apos ) {
-			$dynamic[ '/\'(\d\d(?:’|\')?s)/' ] = $apos . '$1'; // '99's
-			$dynamic[ '/\'(\d)/'                   ] = $apos . '$1'; // '99
-		}
+
+		// '99s (apostrophe)
+		if ( "'" != $apos )
+			$dynamic[ '/\'(?=\d)/' ] = $apos;
+
+		// Single quote at start, or preceded by (, {, <, [, ", or spaces.
 		if ( "'" != $opening_single_quote )
-			$dynamic[ '/(\s|\A|[([{<]|")\'/'       ] = '$1' . $opening_single_quote; // opening single quote, even after (, {, <, [
+			$dynamic[ '/(?<=\A|[([{<"]|' . $spaces . ')\'/' ] = $opening_single_quote;
+
+		// 9" (double prime)
 		if ( '"' != $double_prime )
-			$dynamic[ '/(\d)"/'                    ] = '$1' . $double_prime; // 9" (double prime)
+			$dynamic[ '/(?<=\d)"/' ] = $double_prime;
+
+		// 9' (prime)
 		if ( "'" != $prime )
-			$dynamic[ '/(\d)\'/'                   ] = '$1' . $prime; // 9' (prime)
+			$dynamic[ '/(?<=\d)\'/' ] = $prime;
+
+		// Apostrophe in a word.  No spaces or double primes.
 		if ( "'" != $apos )
-			$dynamic[ '/(\S)\'([^\'\s])/'          ] = '$1' . $apos . '$2'; // apostrophe in a word
+			$dynamic[ '/(?<!' . $spaces . ')\'(?!\'|' . $spaces . ')/' ] = $apos;
+
+		// Double quote at start, or preceded by (, {, <, [, or spaces, and not followed by spaces.
 		if ( '"' != $opening_quote )
-			$dynamic[ '/(\s|\A|[([{<])"(?!\s)/'    ] = '$1' . $opening_quote . '$2'; // opening double quote, even after (, {, <, [
+			$dynamic[ '/(?<=\A|[([{<]|' . $spaces . ')"(?!' . $spaces . ')/' ] = $opening_quote;
+
+		// Any remaining double quotes.
 		if ( '"' != $closing_quote )
-			$dynamic[ '/"(\s|\S|\Z)/'              ] = $closing_quote . '$1'; // closing double quote
+			$dynamic[ '/"/' ] = $closing_quote;
+
+		// Single quotes followed by spaces.
 		if ( "'" != $closing_single_quote )
-			$dynamic[ '/\'([\s.]|\Z)/'             ] = $closing_single_quote . '$1'; // closing single quote
+			$dynamic[ '/\'(?=\Z|' . $spaces . ')/' ] = $closing_single_quote; 
 
-		$dynamic[ '/\b(\d+)x(\d+)\b/'              ] = '$1&#215;$2'; // 9x9 (times)
+		// 9x9 (times)
+		$dynamic[ '/\b(\d+)x(\d+)\b/' ] = '$1&#215;$2';
 
 		$dynamic_characters = array_keys( $dynamic );
 		$dynamic_replacements = array_values( $dynamic );