--- taxonomy.module	Fri Jan 16 05:21:36 1970
+++ taxonomy.module	Fri Jan 16 05:21:36 1970
@@ -349,9 +349,17 @@
     db_query('INSERT INTO {term_hierarchy} (tid, parent) VALUES (%d, %d)', $form_values['tid'], $form_values['parent']);
   }
 
+  $values = false;
+  $saved_synonyms = db_fetch_object(db_query('SELECT GROUP_CONCAT(name) AS names FROM term_synonym WHERE tid = %d', $form_values['tid']))->names;
   db_query('DELETE FROM {term_synonym} WHERE tid = %d', $form_values['tid']);
   if (!empty($form_values['synonyms'])) {
-    foreach (explode ("\n", str_replace("\r", '', $form_values['synonyms'])) as $synonym) {
+    $values = explode ("\n", str_replace("\r", '', $form_values['synonyms']));
+  }
+  elseif ($saved_synonyms !== null && !isset($form_values['synonyms'])) {
+    $values = preg_split('/,/', $saved_synonyms);
+  }
+  if ($values !== false) {
+    foreach ($values as $synonym) {
       if ($synonym) {
         db_query("INSERT INTO {term_synonym} (tid, name) VALUES (%d, '%s')", $form_values['tid'], chop($synonym));
       }