+
+function is_conversion_safe($input_charset) {
+ global $languages, $sm_notAlias, $default_charset;
+
+ // convert to lower case
+ $input_charset = strtolower($input_charset);
+
+ // Is user's locale Unicode based ?
+ if ( $default_charset == "utf-8" ) {
+ return true;
+ }
+
+ // Charsets that are similar
+switch ($default_charset):
+case "windows-1251":
+ if ( $input_charset == "iso-8859-5" ||
+ $input_charset == "koi8-r" ||
+ $input_charset == "koi8-u" ) {
+ return true;
+ } else {
+ return false;
+ }
+case "windows-1257":
+ if ( $input_charset == "iso-8859-13" ||
+ $input_charset == "iso-8859-4" ) {
+ return true;
+ } else {
+ return false;
+ }
+case "iso-8859-4":
+ if ( $input_charset == "iso-8859-13" ||
+ $input_charset == "windows-1257" ) {
+ return true;
+ } else {
+ return false;
+ }
+case "iso-8859-5":
+ if ( $input_charset == "windows-1251" ||
+ $input_charset == "koi8-r" ||
+ $input_charset == "koi8-u" ) {
+ return true;
+ } else {
+ return false;
+ }
+case "iso-8859-13":
+ if ( $input_charset == "iso-8859-4" ||
+ $input_charset == "windows-1257" ) {
+ return true;
+ } else {
+ return false;
+ }
+case "koi8-r":
+ if ( $input_charset == "windows-1251" ||
+ $input_charset == "iso-8859-5" ||
+ $input_charset == "koi8-u" ) {
+ return true;
+ } else {
+ return false;
+ }
+case "koi8-u":
+ if ( $input_charset == "windows-1251" ||
+ $input_charset == "iso-8859-5" ||
+ $input_charset == "koi8-r" ) {
+ return true;
+ } else {
+ return false;
+ }
+default:
+ return false;
+endswitch;
+}