Index: includes/common.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/common.inc,v
retrieving revision 1.756.2.84
diff -u -p -r1.756.2.84 common.inc
--- includes/common.inc	19 May 2010 14:59:34 -0000	1.756.2.84
+++ includes/common.inc	20 May 2010 19:52:10 -0000
@@ -2443,9 +2443,22 @@ function drupal_to_js($var) {
       return $var;
     case 'resource':
     case 'string':
-      return '"'. str_replace(array("\r", "\n", "<", ">", "&"),
-                              array('\r', '\n', '\x3c', '\x3e', '\x26'),
-                              addslashes($var)) .'"';
+      $replace_pairs = array(
+        "\\" => '\u005c',
+        "<" => '\u003c',
+        ">" => '\u003e',
+        "&" => '\u0026',
+        '"' => '\u0022',
+        '/' => '\u002f',
+        "\xc2\x85" => '\u0085', // Next Line
+        "\xe2\x80\xa8" => '\u2028', // Line Separator
+        "\xe2\x80\xa9" => '\u2029', // Paragraph Separator
+      );
+      // Remaining unicode replacements.
+      for ($i = 0; $i < 32; $i++) {
+        $replace_pairs[html_entity_decode('&#'. $i .';', ENT_NOQUOTES, 'UTF-8')] = '\u00' . sprintf("%02s", dechex($i));
+      }
+      return '"'. strtr($var, $replace_pairs) .'"';
     case 'array':
       // Arrays in JSON can't be associative. If the array is empty or if it
       // has sequential whole number keys starting with 0, it's not associative