Remove invalid chars from displayed string per XML specification

dregad · dregad · commit 2b5d66217bd4 · 2012-09-26T18:20:41.000+02:00
Strict XHTML requires that data comply with XML 1.0 specification [1], which only allows a subset of the UTF-8 charset. Function string_html_specialchars() has been modified to remove from the string to print, any character which is not in the defined range Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] Fixes #14744 [1] http://www.w3.org/TR/xml/
diff --git a/core/string_api.php b/core/string_api.php
@@ -910,6 +910,10 @@ function string_html_entities( $p_string ) {
  * @return string
  */
 function string_html_specialchars( $p_string ) {
+	# Remove any invalid character from the string per XML 1.0 specification
+	# http://www.w3.org/TR/2008/REC-xml-20081126/#NT-Char
+	$p_string = preg_replace( '/[^\x9\xA\xD\x20-\xD7FF\xE000-\xFFFD\x{10000}-\x{10FFFF}]/u', '', $p_string );
+
 	# achumakov: @ added to avoid warning output in unsupported codepages
 	# e.g. 8859-2, windows-1257, Korean, which are treated as 8859-1.
 	# This is VERY important for Eastern European, Baltic and Korean languages
