+ // else use normal substr_replace()
+ //
+ return is_null($length) ? substr_replace($string, $replacement, $start)
+ : substr_replace($string, $replacement, $start, $length);
+
+}
+
+/**
+ * Wrapper that is used to switch between vanilla and multibyte strpos
+ * functions.
+ * @param string $haystack
+ * @param mixed $needle
+ * @param integer $offset
+ * @param string $charset
+ * @return string
+ * @since 1.5.1
+ * @link http://www.php.net/strpos
+ * @link http://www.php.net/mb_strpos
+ */
+function sq_strpos($haystack,$needle,$offset,$charset='auto') {
+ // use automatic charset detection, if function call asks for it
+ static $charset_auto, $bUse_mb;
+
+ if ($charset=='auto') {
+ if (!isset($charset_auto)) {
+ global $default_charset, $squirrelmail_language;
+ set_my_charset();
+ $charset=$default_charset;
+ if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
+ $charset_auto = $charset;
+ } else {
+ $charset = $charset_auto;
+ }
+ }
+ $charset = strtolower($charset);
+
+ // in_array call is expensive => do it once and use a static var for
+ // storing the results
+ if (!isset($bUse_mb)) {
+ if (in_array($charset,sq_mb_list_encodings())) {
+ $bUse_mb = true;
+ } else {
+ $bUse_mb = false;
+ }
+ }
+ if ($bUse_mb) {
+ return mb_strpos($haystack,$needle,$offset,$charset);
+ }
+ // TODO: add mbstring independent code
+
+ // use vanilla string functions as last option
+ return strpos($haystack,$needle,$offset);
+}
+
+/**
+ * Wrapper that is used to switch between vanilla and multibyte strtoupper
+ * functions.
+ * @param string $string
+ * @param string $charset
+ * @return string
+ * @since 1.5.1
+ * @link http://www.php.net/strtoupper
+ * @link http://www.php.net/mb_strtoupper
+ */
+function sq_strtoupper($string,$charset='auto') {
+ // use automatic charset detection, if function call asks for it
+ static $charset_auto, $bUse_mb;
+
+ if ($charset=='auto') {
+ if (!isset($charset_auto)) {
+ global $default_charset, $squirrelmail_language;
+ set_my_charset();
+ $charset=$default_charset;
+ if ($squirrelmail_language=='ja_JP') $charset='euc-jp';
+ $charset_auto = $charset;
+ } else {
+ $charset = $charset_auto;
+ }
+ }
+ $charset = strtolower($charset);
+
+ // in_array call is expensive => do it once and use a static var for
+ // storing the results
+ if (!isset($bUse_mb)) {
+ if (function_exists('mb_strtoupper') &&
+ in_array($charset,sq_mb_list_encodings())) {
+ $bUse_mb = true;
+ } else {
+ $bUse_mb = false;
+ }
+ }
+
+ if ($bUse_mb) {
+ return mb_strtoupper($string,$charset);
+ }
+ // TODO: add mbstring independent code
+
+ // use vanilla string functions as last option
+ return strtoupper($string);
+}
+
+/**
+ * Counts 8bit bytes in string
+ * @param string $string tested string
+ * @return integer number of 8bit bytes
+ */
+function sq_count8bit($string) {
+ $count=0;
+ for ($i=0; $i<strlen($string); $i++) {
+ if (ord($string[$i]) > 127) $count++;
+ }
+ return $count;
+}
+
+/**
+ * Callback function to trim whitespace from a value, to be used in array_walk
+ * @param string $value value to trim
+ * @since 1.5.2 and 1.4.7
+ */
+function sq_trim_value ( &$value ) {
+ $value = trim($value);
+}
+
+/**
+ * Truncates the given string so that it has at
+ * most $max_chars characters. NOTE that a "character"
+ * may be a multibyte character, or (optionally), an
+ * HTML entity , so this function is different than
+ * using substr() or mb_substr().
+ *
+ * NOTE that if $elipses is given and used, the returned
+ * number of characters will be $max_chars PLUS the
+ * length of $elipses
+ *
+ * @param string $string The string to truncate
+ * @param int $max_chars The maximum allowable characters
+ * @param string $elipses A string that will be added to
+ * the end of the truncated string
+ * (ONLY if it is truncated) (OPTIONAL;
+ * default not used)
+ * @param boolean $html_entities_as_chars Whether or not to keep
+ * HTML entities together
+ * (OPTIONAL; default ignore
+ * HTML entities)
+ *
+ * @return string The truncated string
+ *
+ * @since 1.4.20 and 1.5.2 (replaced truncateWithEntities())
+ *
+ */
+function sm_truncate_string($string, $max_chars, $elipses='',
+ $html_entities_as_chars=FALSE)
+{
+
+ // if the length of the string is less than
+ // the allowable number of characters, just
+ // return it as is (even if it contains any
+ // HTML entities, that would just make the
+ // actual length even smaller)
+ //
+ $actual_strlen = sq_strlen($string, 'auto');
+ if ($max_chars <= 0 || $actual_strlen <= $max_chars)
+ return $string;
+
+
+ // if needed, count the number of HTML entities in
+ // the string up to the maximum character limit,
+ // pushing that limit up for each entity found
+ //
+ $adjusted_max_chars = $max_chars;
+ if ($html_entities_as_chars)
+ {
+
+ // $loop_count is needed to prevent an endless loop
+ // which is caused by buggy mbstring versions that
+ // return 0 (zero) instead of FALSE in some rare
+ // cases. Thanks, PHP.
+ // see: http://bugs.php.net/bug.php?id=52731
+ // also: tracker $3053349
+ //
+ $loop_count = 0;
+ $entity_pos = $entity_end_pos = -1;
+ while ($entity_end_pos + 1 < $actual_strlen
+ && ($entity_pos = sq_strpos($string, '&', $entity_end_pos + 1)) !== FALSE
+ && ($entity_end_pos = sq_strpos($string, ';', $entity_pos)) !== FALSE
+ && $entity_pos <= $adjusted_max_chars
+ && $loop_count++ < $max_chars)
+ {
+ $adjusted_max_chars += $entity_end_pos - $entity_pos;