Incorrect expression evaluation in drush_print() function

See code (includes\drush.inc, in function drush_print(), line 572):

572:  if ($charset = drush_get_option('output_charset') && function_exists('iconv')) {
573:    $msg = iconv('UTF-8', $charset, $msg);
574:  }

Variable $charset evaluates as boolean (logical AND between drush_get_option() and function_exists()) but should be a string. Parentheses will fix this bug:

if ( ( $charset = drush_get_option('output_charset') ) && function_exists('iconv')) {