Merge branch '0.9.x' into 1.0.x

diff --cc lib/util.php
index b20ed8225f4a991f2e9842fddda8843734ae4b97,35fcfdb090a7f862b446fc6f77e09e61e82d3d12..df339d4b1e39e6058c84ea3d31becf2e1bb05210
--- 1/lib/util.php
--- 2/lib/util.php
+++ b/lib/util.php
@@@ -916,23 -901,33 +916,45 @@@ function common_linkify($url) 
  
  function common_shorten_links($text, $always = false)
  {
 -    $maxLength = Notice::maxContent();
 -    if (!$always && ($maxLength == 0 || mb_strlen($text) <= $maxLength)) return $text;
 -    return common_replace_urls_callback($text, array('File_redirection', 'makeShort'));
 +    common_debug("common_shorten_links() called");
 +
 +    $user = common_current_user();
 +
 +    $maxLength = User_urlshortener_prefs::maxNoticeLength($user);
 +
 +    common_debug("maxLength = $maxLength");
 +
 +    if ($always || mb_strlen($text) > $maxLength) {
 +        common_debug("Forcing shortening");
 +        return common_replace_urls_callback($text, array('File_redirection', 'forceShort'));
 +    } else {
 +        common_debug("Not forcing shortening");
 +        return common_replace_urls_callback($text, array('File_redirection', 'makeShort'));
 +    }
  }
  
+ /**
+  * Very basic stripping of invalid UTF-8 input text.
+  *
+  * @param string $str
+  * @return mixed string or null if invalid input
+  *
+  * @todo ideally we should drop bad chars, and maybe do some of the checks
+  *       from common_xml_safe_str. But we can't strip newlines, etc.
+  * @todo Unicode normalization might also be useful, but not needed now.
+  */
+ function common_validate_utf8($str)
+ {
+     // preg_replace will return NULL on invalid UTF-8 input.
+     return preg_replace('//u', '', $str);
+ }
+ 
+ /**
+  * Make sure an arbitrary string is safe for output in XML as a single line.
+  *
+  * @param string $str
+  * @return string
+  */
  function common_xml_safe_str($str)
  {
      // Replace common eol and extra whitespace input chars