#315047 by Josh Waihi: Escape PostgreSQL column names in the changeField function.

includes/database/pgsql/schema.inc

@@ -547,7 +547,7 @@ public function dropIndex(&$ret, $table, $name) {
    *   table specification but without the 'fields' element.
    */
   public function changeField(&$ret, $table, $field, $field_new, $spec, $new_keys = array()) {
-    $ret[] = update_sql("ALTER TABLE {" . $table . "} RENAME $field TO " . $field . "_old");
+    $ret[] = update_sql('ALTER TABLE {' . $table . '} RENAME "' . $field . '" TO "' . $field . '_old"');
     $not_null = isset($spec['not null']) ? $spec['not null'] : FALSE;
     unset($spec['not null']);