CRM-13745 - fix mysql exception

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* CRM-13745: CRM_Contact_Form_Search_Custom_FullText: broken links from search results
  http://issues.civicrm.org/jira/browse/CRM-13745

CRM/Contact/Form/Search/Custom/FullText.php

@@ -838,10 +838,16 @@ WHERE      (c.sort_name LIKE {$this->_text} OR c.display_name LIKE {$this->_text
     }
   }
 
-  function contactIDs($offset = 0, $rowcount = 0, $sort = NULL) {
+  function contactIDs($offset = 0, $rowcount = 0, $sort = NULL, $returnSQL = FALSE) {
     $this->initialize();
 
-    return CRM_Core_DAO::singleValueQuery("SELECT contact_id FROM {$this->_tableName}");
+    $sql = "SELECT contact_id FROM {$this->_tableName}";
+    if ($returnSQL) {
+      return $sql;
+    }
+    else {
+      return CRM_Core_DAO::singleValueQuery($sql);
+    }
   }
 
   function all($offset = 0, $rowcount = 0, $sort = NULL, $includeContactIDs = FALSE, $justIDs = FALSE) {